USRE42161E1 - Power supply for light emitting diode array - Google Patents

Power supply for light emitting diode array Download PDF

Info

Publication number
USRE42161E1
USRE42161E1 US09382702 US38270299A USRE42161E1 US RE42161 E1 USRE42161 E1 US RE42161E1 US 09382702 US09382702 US 09382702 US 38270299 A US38270299 A US 38270299A US RE42161 E1 USRE42161 E1 US RE42161E1
Authority
US
Grant status
Grant
Patent type
Prior art keywords
power
means
input
output
voltage
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US09382702
Inventor
Peter Anthony Hochstein
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
AGREEMENT AND DECLARATION OF TRUST DATED JUNE 1 2009
Original Assignee
Relume Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Grant date
Family has litigation

Links

Images

Classifications

    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02MAPPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00Details of apparatus for conversion
    • H02M1/42Circuits or arrangements for compensating for or adjusting power factor in converters or inverters
    • H02M1/4208Arrangements for improving power factor of AC input
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J9/00Circuit arrangements for emergency or standby power supply, e.g. for emergency lighting
    • H02J9/04Circuit arrangements for emergency or standby power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source
    • H02J9/06Circuit arrangements for emergency or standby power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over
    • H02J9/062Circuit arrangements for emergency or standby power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over involving non rotating DC/AC converters
    • H02J9/065Circuit arrangements for emergency or standby power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over involving non rotating DC/AC converters for lighting purposes
    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05BELECTRIC HEATING; ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR
    • H05B33/00Electroluminescent light sources
    • H05B33/02Details
    • H05B33/08Circuit arrangements not adapted to a particular application
    • H05B33/0803Circuit arrangements not adapted to a particular application for light emitting diodes [LEDs] comprising only inorganic semiconductor materials
    • H05B33/0842Circuit arrangements not adapted to a particular application for light emitting diodes [LEDs] comprising only inorganic semiconductor materials with control
    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05BELECTRIC HEATING; ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR
    • H05B33/00Electroluminescent light sources
    • H05B33/02Details
    • H05B33/08Circuit arrangements not adapted to a particular application
    • H05B33/0803Circuit arrangements not adapted to a particular application for light emitting diodes [LEDs] comprising only inorganic semiconductor materials
    • H05B33/0842Circuit arrangements not adapted to a particular application for light emitting diodes [LEDs] comprising only inorganic semiconductor materials with control
    • H05B33/0845Circuit arrangements not adapted to a particular application for light emitting diodes [LEDs] comprising only inorganic semiconductor materials with control of the light intensity
    • H05B33/0848Circuit arrangements not adapted to a particular application for light emitting diodes [LEDs] comprising only inorganic semiconductor materials with control of the light intensity involving load characteristic sensing means
    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05BELECTRIC HEATING; ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR
    • H05B33/00Electroluminescent light sources
    • H05B33/02Details
    • H05B33/08Circuit arrangements not adapted to a particular application
    • H05B33/0803Circuit arrangements not adapted to a particular application for light emitting diodes [LEDs] comprising only inorganic semiconductor materials
    • H05B33/0884Circuit arrangements not adapted to a particular application for light emitting diodes [LEDs] comprising only inorganic semiconductor materials with monitoring or protection
    • H05B33/0887Circuit arrangements not adapted to a particular application for light emitting diodes [LEDs] comprising only inorganic semiconductor materials with monitoring or protection of the conversion stage
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02BCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/10Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion
    • Y02B70/12Power factor correction technologies for power supplies
    • Y02B70/126Active technologies

Abstract

An apparatus (10) for supplying regulated voltage d.c. electrical power to an LED array (12) includes a rectifier (32) responsive to a.c. power for generating rectified d.c. power and a power factor correcting and voltage regulating buck/boost switchmode converter (38) responsive to the rectified d.c. power for generating regulated voltage d.c. power to illuminate the LED array (12). A battery backup system (62) receives the a.c. power applied to the rectifier (32) for charging a rechargeable battery (66) and sensing an a.c. power failure. A switch-over relay (82) is connected between the battery backup system (62) and the rectifier. Upon sensing a failure of the a.c. power, the battery backup system (62) controls the switch-over relay (82) to connect the battery backup system (62) to the rectifier (32) to provide d.c. power to the switchmode converter (38) to illuminate the LED array (12). A half wave power detector (88) causes the apparatus (10) to reduce regulated d.c. power to dim the LED array (12).

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the parent of a continuation reissue application filed Mar. 5, 2008, and accorded application Ser. No. 12/074,723.

BACKGROUND OF THE INVENTION

The present invention relates generally to an apparatus for generating power to a light emitting diode array and, in particular, to a power supply for operating light emitting diode array traffic signals.

Light emitting diode (LED) arrays are becoming more common in many applications as they are used to replace less efficient incandescent lamps. Status annunciators, message boards, liquid crystal display back lights and traffic signals are common applications for LED arrays. In most of these uses, electrical power is obtained from a.c. mains (120 v.a.c., 60 Hz) and some form of power supply converts the alternating line voltage to d.c., or pulsing d.c., for powering the plurality of LEDs.

LEDs typically exhibit forward voltage drops on the order of 1.2 to 2.0 volts when driven at average currents of 20 to 25 ma. For purposes of efficiency, the LEDs are usually connected in series so that a higher power supply voltage can be used to light an array of LEDs.

In many applications where a relatively large number of LEDs are necessary to deliver substantial light output, several series strings of LEDs with a ballasting resistor in each string are normally connected in parallel. As shown in the FIG. 1., this traditional circuit arrangement provides some redundancy from single point LED failure, as any “open” LED will only extinguish its own series string leaving the other strings active. Since this relatively simple circuit does not provide any regulation, i.e. the light output varies with varying input voltage, it has been generally superseded by the regulated circuit shown in the FIG. 2. The regulated circuit employs a linear current regulator instead of individual ballasting resistors to maintain a given current through the LED strings. The highly dissipative nature of such linear regulators makes such use questionable in heat sensitive apparatus such as LED signals however. Heat generated by the regulator could exacerbate the deterioration of the thermally sensitive LEDs.

A non dissipative. unregulated power supply for LED signals is shown in FIG. 3, and uses a series capacitor as the current limiting element. Such highly reactive power supplies exhibit very poor power factors however, and may be disallowed by power utilities.

Several problems are associated with these prior art simple circuit topologies. The input current wave forms are generally badly distorted and the power factor is poor. Reasons for the poor power factor and high distortion relate to the discontinuous conduction of the diodes in the circuit feeding large capacitors. This phenomenon is well understood, and plagues many small off line power supplies. Until recently these concerns were essentially disregarded by the electrical power industry because the impact to the power grid was relatively small. Of course, as larger numbers of these low power appliances are connected to the power grid, the effect is no longer inconsequential. In fact, many utilities are placing limits on permissible power factor and distortion behavior of electrical devices connected to their lines.

LED traffic signals are being retrofitted in place of incandescent lamps primarily because of the energy savings common to LED signals. For example, an 8 inch diameter incandescent signal might consume 67 watts and its LED equivalent 14 watts, or a 12 inch diameter incandescent signal would consume 150 watts while its LED replacement would consume only 28 watts. The dramatic energy savings translate into greatly reduced operating cost, which is an important criterion, as electrical power is becoming more expensive. Also, in many parts of the country, electrical generating capacity is at its limits, and new capacity cannot be added because of environmental concerns. This strong interest in LED signals as an important energy conservation resource is clouded however by the poor power factor performance of commercially available signals.

Power factor (p.f.) is well understood in the electrical engineering community as the ratio of real power to real power plus reactive power, or more conveniently. p.f.=cos θ where θ is the angle in electrical degrees of the current-voltage phase offset. That is, in many reactive loads powered by sinusoidal (alternating) current, the voltage and current may be out of phase.

The apparent power that has to be delivered to a given load in volt-amperes (VA) is, therefore equal to the true power consumption of the device in Watts divided by the power factor. For example, an appliance with an internal power consumption of 100 Watts that exhibited a power factor of 0.4, would require 100/0.4 or 250 VA of energy from the power line and utility generator. Taken separately, the many small electrical appliances that are widely used have only a moderate effect on generating capacity. However in aggregate, a large number of small devices can have a significant impact on the power grid.

By means of example, a medium size city (San Francisco) may have some 2000 signalized intersections with a total of 16,000 mixed 8 inch and 12 inch traffic signals. If the existing incandescent signals with an average power consumption of 100 watts are replaced with LED variants of 20 watt rating, a significant power saving should result. The 1600 kilowatt (kW) load imposed by the incandescent signals should be reduced to 320 kw by the LED retrofit devices. However, if the LED signals exhibit an actual power factor of 0.3, the resulting load to the power grid is 320 kW divided by 0.3 p.f. or 1067 kW. The energy savings is then only 533 kW, which is the net mount of power that the utility can convert to other uses. Clearly then, the need for power factors close to unity is apparent. Another factor that directly influences the amount of power (apparent VA) that needs to be delivered to a given load is the total harmonic distortion of the current waveform supplying the device. True power factor is adversely affected by current or voltage distortion, and the significance of this influence is only now being widely accepted. There is shown in the FIG. 4, a traditional power factor vector diagram (which is normally two dimensional) which has been expanded to a three dimensional form to indicate the influence of distortion on the apparent power vector. The total power required vector VA (apparent power) is determined by the combination of the working power vector WATTS, the volt-amperes reactive vector VAR (non-working power) and the distortion volt-amperes vector DVA (non-working power).

Harmonic distortion or deviation from true sinusoidal wave forms not only gives rise to further wasted energy, but increases the electromagnetic interference potential of the load. Radiated and conducted interference is a concern because of the interference potential with other services (radio communications for example).

Harmonic distortion is becoming more prevalent in power supplies as these devices are converted from inefficient linear operation to far more efficient switchmode operation. A wide variety of circuit topologies are used in modern switching power supplies such as thyristor and triac phase control, or bipolar or field effect transistor switches. A consequence of these solid state approaches is increased harmonic distortion and poor power factor behavior. In order to mitigate these problems, several approaches to power factor and distortion control have been developed that operate with and use the efficiency of the switchmode power supply itself. That is, instead of correcting for power factor in a separate functional device (that is connected between the power supply and line), the power factor and distortion correcting function is part of the switchmode power supply. A number of manufacturers of integrated circuits (Linear Technology, Silicon General, Motorola and Unitrode for example) offer monolithic devices that perform the power factor and distortion control function. A review of this art is presented in Power Supply Cookbook by Marty Brown, 1994, Butterworth-Heinemann.

SUMMARY OF THE INVENTION

The present invention concerns an apparatus for supplying regulated voltage d.c. electrical power to an LED array. The apparatus includes a rectifier having an input and an output, the rectifier being responsive to a.c power at the input for generating rectified d.c. power at the output, a power factor correction converter having an input connected to the rectifier output and an output, the power factor correction converter being responsive to the rectified d.c. power at the power factor correction converter input for generating regulated voltage, d.c. power at the power factor correction converter output, and an LED array having an input connected to the power factor correction converter output for receiving the d.c. power to illuminate the LED array. The power factor correction converter can be a power factor correcting and voltage regulating buck/boost switchmode converter.

A primary object of the present invention is to provide a power factor correcting, (boost buck/boost or buck) switchmode converter to power a line operated LED signal.

Another object of the present invention is to use the inherent pulse modulating nature of a switchmode power supply to provide voltage regulation to an LED array.

The apparatus according to the present invention also includes an adaptive clamp circuit connected to the rectifier input for eliminating leakage current problems. The adaptive clamp circuit has an input adapted to be connected to a pair of a.c. power lines, a pair of clamp circuit output lines connected to the adaptive clamp circuit input, a voltage sensing means connected across the adaptive clamp circuit input, and a controlled load means connected across the clamp circuit output lines and to the voltage sensing means. The voltage sensing means is responsive to a magnitude of a.c. voltage at the adaptive clamp circuit input lower than a predetermined magnitude for turning on the controlled load means to connect a low impedance load in the controlled load means across the clamp circuit output lines and the voltage sensing means is responsive to a magnitude of the a.c. voltage at the adaptive clamp circuit input equal to or greater than the predetermined magnitude for turning off the controlled load means to disconnect the low impedance load from the clamp circuit output lines.

It is also an objective of the present invention to eliminate leakage current problems by providing an adaptive clamp circuit.

Another feature of the present invention is to provide an adaptive line loading means or clamp that switches itself in or out of the circuit as needed.

The apparatus according to the present invention further includes a battery backup system having an input for receiving a.c. power applied to the rectifier input and having an output at which d.c. power is generated, and a switch-over relay connected to the battery backup system output and to the rectifier input, the battery backup system being responsive to a failure of a.c. power at the battery backup system input for controlling the switch-over relay to connect the battery backup system output to the rectifier input to provide d.c. power to illuminate the LED array and being responsive to a.c. power at the battery backup system input for controlling the switch-over relay to disconnect the battery backup system output from the rectifier input.

Another object of the present invention is the use of a d.c. power supply (instead of the a.c. power line) as a power backup that is activated upon a.c. power line loss.

BRIEF DESCRIPTION OF THE DRAWINGS

The above, as well as other advantages of the present invention, will become readily apparent to those skilled in the art from the following detailed description of a preferred embodiment when considered in the light of the accompanying drawings in which:

FIG. 1 is a schematic diagram of a prior art unregulated power supply for LED signals;

FIG. 2 is a schematic diagram of a prior art linear current regulated power supply for LED signals;

FIG. 3 is a schematic diagram of a prior art reactively ballasted power supply for LED signals;

FIG. 4 is a three dimensional vector diagram of the total power required to operate an LED array;

FIG. 5 is a schematic diagram of a regulated voltage, switchmode power supply for LED signals in accordance with the present invention;

FIG. 6a is a schematic block diagram of the adaptive clamp circuit shown in the FIG. 5;

FIG. 6b is a schematic diagram of the adaptive clamp circuit shown in the FIG. 6a; and

FIG. 7 is a schematic block diagram of a battery backup system for LED signals according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

As noted above, the elementary power supplies that are currently used for powering LED array signals do not meet current standards for efficiency, reliability and performance. The unregulated, resistively ballasted power supply shown in the FIG. 1 does not isolate the LEDs from line voltage variations, and exhibits a poor power factor because of the rectifier and large capacitor. The commercially produced current regulated LED power supply, which is shown in the FIG. 2, does provide much better LED light intensity regulation with input voltage variation. However, the use of a linear, dissipative (heat producing) regulator presents problems. LEDs are thermally sensitive devices which degrade quickly at elevated temperatures. Since most power supplies for LED signals are part of, or are attached to the LED array, heat rise from the linear regulator can be deleterious. Furthermore, the traditional rectifier-capacitor circuit does not produce a satisfactory power factor.

The use of capacitors as non-dissipative current limiters in a.c. circuits is well established, and is shown in the FIG. 3 as another example of a commercially available LED array signal power supply. Current and voltage wave forms are essentially out of phase in this type of circuit so that heat is not generated in the current limiting capacitor (15 μF). However, the power factor and distortion performance of this type of circuit is very poor (P.F.≈0.3).

There is shown in the FIG. 5, a regulated voltage, switchmode power supply 10 according to the present invention connected to an LED array 12. The LED array 12 includes a plurality of strings of series connected LEDs 14 with a ballasting resistor 16 (R1, R2, R3, R4, R5, . . . ) connected in each string. The strings are connected in parallel between a first input line 18 and a second input line 20 of the LED array 12.

The power supply 10 has a pair of power input lines 22 for connection to a source (not shown) of a.c. power such as main power lines at a nominal 120 volts a.c. An input of an adaptive clamp circuit 24 can be connected to the lines 22 as an option. A problem peculiar to signals that are switched by means of solid state relays is the leakage current that can flow through the load when the solid state switch or relay is “OFF”. This phenomenon is common to triac and thyristor switches that are commonly employed in traffic signal controllers. While not apparent when incandescent signals are employed (because they are low impedance loads), the problems surface when relatively low power loads (such as LEDs) are connected to these same controllers. Typically, other safety devices used in traffic signal controllers such as conflict monitors must be “tricked” to reduce this leakage current. Commonly, a large capacitor is placed across the a.c. input leads to the LED load, in order to absorb the leakage current reactively. Of course, such provisions only aggravate the power factor problems.

An output of the adaptive clamp circuit 24 is connected by a pair of clamp circuit output lines 26 to an input of an electromagnetic interference (E.M.I.) filter 28. The E.M.I. filter 28 keeps conducted interference from feeding back into the power lines where it might cause problems to other circuitry on the line. An output of the filter 28 is connected by a pair of filter output lines 30 to an input of a rectifier means 32 which converts the incoming a.c. power to a pulsing d.c. power generated on a positive polarity rectifier output line 34 and a negative polarity rectifier output line 36. Although the rectifier means is shown as a full wave diode bridge rectifier, any type of rectifier can be used. The lines 34 and 36 are connected to an input of a power factor correction, buck/boost converter 38. The converter 38 includes a power factor correction (P.F.C.) integrated circuit (I.C.) controller 40, which is a commercial device available from many sources and functions by allowing current to charge a storage capacitor C (LARGE) only in phase with the rectified a.c. voltage thereby assuring a power factor close to unity. The control I.C. 40 also provides voltage regulation in the switchmode buck/boost converter by monitoring the output voltage and adjusting the high frequency on-off switching period of the pass element commensurately. Although a buck/boost converter is diagrammed, buck or boost topologies are also possible. Voltage output and current-mode control techniques are the primary differences in the various geometries, but these details are incidental to the functionality of the circuit.

A positive polarity output of the converter 38 is connected by a positive polarity converter output line 42 to the first input line 18 of the LED array 12. A negative polarity output of the converter 38 is connected by a negative polarity convener output line 44 to the second input line 20 of the LED array 12 through an optional pulse width modulated (P.W.M.) modulator 46.

The output voltage from the P.F.C. switch mode converter 38 is either fed directly to the LED array 12, or alternatively through the P.W.M. modulator 46. Such pulse modulation has been shown to be advantageous in certain LED signal applications. The functions of the switchmode P.F.C. converter 38 as the off line power supply are the same irrespective of the load. The obvious advantage of using a switching, voltage regulated power supply is efficiency. Line isolation, which is generally not provided by this transformerless design, is generally unnecessary for insulated LED signals, but a high frequency transformer could be incorporated. The intrinsic power factor correction provided by using the switchmode converter 38 in conjunction with the P.F.C. integrated circuit controller 40 is not only cost effective, but allows d.c. backup power to be used in case of line failure.

A primary aspect of the present invention is the use of a power factor correcting, (boost, buck/boost or buck) switchmode converter to power a line operated LED array signal 12. Another function of the present invention is to use the inherent pulse modulating nature of the switchmode power supply to provide voltage regulation to the LED array signal 12. Instead of using dissipative (heat producing) linear regulators for either voltage or current (to accommodate line voltage variations), the power factor and distortion controlling switchmode power supply 10 is used as an efficient voltage regulator. That is, the LED array 12, consisting of a large number of series-parallel connected LED devices 14, can be kept at essentially constant luminosity over a substantial range of input voltages. In actual practice, the output of such LED array signals has been kept within ±10% of nominal value over a power line variation of 85 volts to 140 volts (for a nominal 120 v.a.c. line).

It is also an objective of the present invention to eliminate leakage current problems by providing the adaptive clamp circuit 24 which is shown in more detail in the FIGS. 6a and 6b. The power input lines 22 are connected directly through the adaptive clamp circuit 24 to the clamp circuit output lines 26. The adaptive clamp circuit 24 monitors the input voltage feeding the LED array 12 on the input lines 22 with a voltage sensing means 48 connected across the lines 22 and loads the input lines resistively with a low impedance controlled load means 50, connected across the output lines 26, whenever the line voltage is below some critical amount (typically 40 volts a.c. r.m.s.). The adaptive clamp circuit 24 assumes that voltages lower than a certain value (typically 40 volts) are due to leakage currents through the solid state control relay or switch. The adaptive clamp circuit 24 loads the lines with a resistor to draw current, forcing the leakage voltage to a lower voltage (typically on the order of 10 volts a.c.) that will not cause problems for the conflict monitor or power factor correction (p.f.c.) circuit. Most traffic signals must be capable of being flashed (at least the red and yellow signals) from the traffic controller electronics. It has been found experimentally that residual leakage currents interfere with the ability to flash signals that are equipped with power factor correction circuits. The adaptive clamp circuit 24 prevents this problem by allowing the p.f.c. circuit to completely discharge between power line pulses which flash the signal at a nominal sixty flashes per minute. In summary, the adaptive clamp circuit 24 performs two functions by reducing the leakage voltage: 1) it provides a reactance free means to eliminate problems with conflict monitors (while preventing poor power factors); and 2) it allows the p.f.c. circuit to properly flash the LED array signal 12.

The adaptive clamp circuit 24 is shown in more detail in the FIG. 6b wherein a first pair of diodes D3 and D4 has anodes connected to the lines 22 and cathodes connected together. A second pair of diodes D1 and D2 has cathodes connected to the lines 26 and anodes connected together. A first resistor (R1) 52 is connected between the junction of the second pair of diodes D1 and D2 and an anode of a Zener diode D5. The Zener diode D5 has a cathode connected to the junction of the first pair of diodes D3 and D4. A second resistor (R2) 54 is connected between the anode of the Zener diode D5 and a base of a first NPN transistor Q1. The transistor Q1 has an emitter connected to the junction of the second pair of diodes D1 and D2 and a collector connected through a third resistor (R3) 56 to the junction of the first pair of diodes D3 and D4. A fourth resistor (R4) 58 is connected between the collector of the transistor Q1 and a base of a second NPN transistor Q2. The transistor Q2 has an emitter connected to the junction of the second pair of diodes D1 and D2 and a collector connected through a fifth resistor (R5) 60 to the junction of the first pair of diodes D3 and D4.

The optional adaptive clamping circuit 24 is advantageously placed across the input terminals of the p.f.c., switchmode power supply 10 as shown in the FIG. 5. As noted above, as a consequence of using solid state relays or switches in signal controllers, the power to the signals is not fully disconnected (even when the signal should be off). This leakage current often causes problems with safety devices such as electronic conflict monitors. Additionally, these leakage currents may present problems during flashing operation of LED signals, as the power supply circuits may not be fully discharged between flashes. Switchmode, p.f.c. power suppliers of the type proposed for the present invention are particularly sensitive to such leakage currents and will be inhibited from flashing LEDs at an acceptable rate (55 to 60 flashes per minute).

In current practice, these leakage currents are minimized by “short circuiting” them by means of a reactive, non dissipative element. The input capacitor (typically 1-2 μF), as shown in the FIG. 3 for example, performs this function. However this same capacitor is across the line when the LED array signal is energized, drawing reactive power and contributing to a poor power factor.

Another feature of the present invention is to provide for an adaptive line loading means or clamp that switches itself in or out of circuit as needed. As shown in the FIG. 6b, the adaptive clamp circuit 24 monitors the line voltage, and when only leakage currents are present that drop the line voltage to about 40 v.a.c. the circuit applies a resistive load 60 across the lines 22 by turning on the solid-state switch Q2. When the lines 22 are loaded by the fifth resistor 60, having a suitable value (typically 1 kOhm), the leakage voltage will drop to under 10 volts. At this depressed voltage, the p.f.c. switchmode converter is fully off, and can properly flash the LEDs 14 at the requisite rate.

This adaptive clamp 24 can of course be used with other types of power supplies where the addition of reactive elements could degrade the power factor. The clamping circuit 24 works by using the sensing transistor Q1 and the Zener diode D5 (the voltage sensing means 48 of the FIG. 6a) to determine if the line voltage is below a certain magnitude (typically 40 volts). The sensing transistor Q1 and the Zener diode D5 are the voltage sensing means 48 of the FIG. 6a. If the Zener diode D5 does not conduct, the transistor Q2 is turned on to place the load resistor 60 the power lines 22 causing the leakage voltage to drop below 10 volts. The transistor Q2 and the resistor 60 are the controlled load means 50 of the FIG. 6a. Whenever the traffic signal controller relay “closes”, the line voltage appearing at the input to the adaptive clamping circuit 24 rises to nominally 120 volts and the sensing circuit (Q1 and D5) turn off the controlling transistor Q2, removing the resistor 60 from the circuit thereby preventing unnecessary dissipation of power. Since there are no reactances involved, this circuit does not influence the power factor reflected at the a.c. input lines 22.

Another aspect of the present invention is the use of a d.c. input (instead of the a.c. power line) as a power backup feature that is activated upon power line loss. Conventional practice employs battery driven a.c. inverters to generate the backup power upon line failure. Such inverters are expensive, inefficient and are failure prone. The use of battery power (d.c.) to directly energize the regulated switchmode power supply that powers the LED array signal is very cost effective and energy efficient. The wide input voltage range of most switchmode power supplies allows the batteries to be used optimally as they can be virtually fully discharged in the power backup cycle yielding very good use of battery capacity. Lower cost, smaller batteries are therefore useable.

As noted previously, the use of a direct line operated, non-transformer isolated converter to power the LED array signal allows d.c. power to be used (instead of a.c.) in case of line failure. Using batteries without having to rely on an inverter to perform the d.c. to a.c. conversion is novel, extremely reliable, and cost effective. The importance of battery backup for critical traffic signals is obvious, and the need for reliability is also apparent. As shown in the FIG. 7, a battery backup system 62 includes a temperature compensated, line powered automatic battery charger 64 having an input connected to the lines 22 and an output connected to an input of a rechargeable battery 66 to keep the battery fully charged at all times that a.c. power is available. Temperature compensation can be used to stop the charging process to extend the life of the battery, as it is well known that the optimal end point charging voltage for most secondary cells is a function of temperature.

Because of the critical safety nature of these devices, an automatic battery testing circuit and load 68 is built into the battery backup system 62. Deterioration of the battery 66, which is inevitable ova time, is thereby monitored and degradation past a certain point is nagged or announced. The testing circuit 68 has an input connected to an output of the battery 66 for sensing battery voltage. An alarm signal line 70 is connected to an output of the circuit 68 for generating the alarm signal and a set flag signal line 72 is connected to another output of the circuit 68 for generating the set flag signal. A control line 74 is connected between an output of the circuit 68 and an input of the battery 66. Secondary batteries that are kept in float service for any length of time tend to degrade and loose capacity. This deterioration is far more apparent in high temperature environments, and can adversely affect the safety margins of the backup power supply. That is. instead of providing 8 to 10 hours of flashing red LED array signal backup service, a degraded battery might only last a few hours. Determining the actual condition or serviceability of a storage battery is difficult, because a measurement of terminal voltage does not necessarily indicate loss of capacity. It has been experimentally determined that a good measure of battery capacity can be made by loading the battery with a substantial current (typically 5-10 amperes) for several minutes and measuring the terminal voltage under load. Naturally the battery charger is inhibited during this test. This method is well recognized as a good diagnostic test as it depletes any “surface charge” on the electrodes and more accurately indicates remaining battery ampere-hours.

A voltage comparator circuit in the battery testing circuit and load 68 establishes an “accept” or “reject” level for the battery 66 as it is tested every 24 hours or so. In order to accommodate partly discharged cells, two sequential, battery tests that result in a “reject” are registered in a latch which may trigger a visual or audible alarm signal on the line 70. Alternatively, a relay or contact closure (flag) may be set to generate a signal on the line 72 so that a data modem can relay the degraded battery information to a central service facility. Of course, such calls or alarm signals are triggered well before the battery is no longer serviceable so that safety is not comprised.

A line failure detection circuit 76 has an input connected to the power lines 22 and another input connected to an output of the battery 66 to receive operating power from the battery. The circuit 76 initiates the power switch-over process whenever a.c. input power is disconnected. An output of the line failure detection circuit 76 is connected to an input of a time delay and restoration circuit 78 which has another input connected to an output of the battery 66 to receive operating power from the battery. The time delay function ensures that short, transient line dropouts are disregarded. An output of the time delay and restoration circuit 78 is connected to an input of a d.c. power switch-over and flasher circuit 80 which has another input connected to an output of the battery 66 to receive operating power from the battery. Outputs of the circuit 80 are connected to a first set of input terminals of a switch-over relay 82. The relay has a second set of terminals connected to red signal outputs of a traffic controller 84 having an input connected to the power lines 22. Output terminals of the switch-over relay 82 are connected to the input of the switchmode converter power supply 10 which is connected to the red LED array signal 12. Normally, the switch-over relay 82 is in the position shown to connect a.c. power on the lines 22 through the traffic controller 84 to the power supply 10.

Generally, line loss in excess of 250 msec will cause the d.c. power switch-over relay 82 to switch the output terminals to disconnect the power supply 10 and the red LED array signal 10 from the traffic controller 84 (and the a.c. feed) and connect them to the d.c. battery 66 through the d.c. power switch-over and flasher circuit 80. Note that the d.c. supply is flashed or pulsed by the circuit 80 at a nominal rate of 60 pulses per minute (1 Hz) to place all the red LED array signals at an intersection in a flashing mode, effecting a four way stop. While an electromechanical switch-over relay 82 is shown for complete isolation of the existing traffic controller 84 and the battery backup system 62, solid state devices could be used.

Whenever the line power is restored, the time delay and restoration circuit 78 will wait some period (typically 10-15 seconds) before the LED array signal 12 is switched back to the a.c. power mode. This delay avoids the many transients that usually accompany a.c. line restoration after a power outage. Note that no inverter is employed in this system, as is common practice in existing commercial hardware. The inefficiency and poor reliability of d.c. to a.c. converters is thereby avoided. Because the switchmode power supply 10 can accommodate wide variations in input voltage (both a.c. and d.c.) the storage battery 66 can be discharged virtually completely while maintaining essentially constant luminosity of the LED array signal 12.

Additionally, as shown in the FIG. 7, there are provisions for the introduction of narrow “marker pulses” superimposed on the d.c. supply for use as synchronizing pulses. An optional synchronizing pulse generator 86 has an output connected to an input of the d.c. power switch-over and flasher circuit 80 for generating such pulses. This optional feature permits a number of LED array signals that are pulse modulated to operate in sync in the absence of the 60 Hz a.c. line signal. These “marker pulses” are essentially short (200 μsec) power dropouts that do not affect the operation of the LED array signal 12, but are easily extracted at the signal to effect pulse synchronization of several pulsed LED array signals.

As noted above, the lack of input transformers or series capacitors before the full wave bridge, allows d.c. power to be applied at the input terminals of the power supply 10 in lieu of a.c. power. Since there are no reactive (a.c.) components in the input circuitry, proper operation of the switchmode converter is maintained, and output voltage regulation is still available. Obviously, the p.f.c. portion of the circuit 10 will be nonfunctional during operation on d.c. input power. As shown, the switchmode convener will provide an essentially constant output voltage (nom. 100 volts d.c.) to the LED array 12 over a range of a.c. input voltages from 85 volts r.m.s. to 140 volts r.m.s. and over a d.c. input voltage range of 38 volts d.c. to 65 volts d.c. The wide (input voltage) operating range allows rechargeable batteries to be used very efficiently, since their capacity can be fully utilized in the discharge cycle, as their terminal voltage drops.

As discussed above, LED signals are being used to replace incandescent lamps in many applications. Traffic signals are among the more common devices that are being upgraded for with LEDs because of the tremendous power savings and the dramatic improvement in service life. In most cases the incandescent lamps are merely replaced with an integral LED retrofit assembly that does not require any modification of the existing traffic signal housing or the drive and control circuitry associated with the signal. That is, users expect the LED retrofit lamps to operate normally without added modifications to the housing or traffic controller.

One aspect of this conversion to LED signals from incandescent lamps poses significant problems however. Many existing incandescent lamp traffic signals are dimmed at night to reduce glare and, of course, power consumption. LED signals can be dimmed by reducing the average current through the LED array. A problem arises however because existing traffic signal controllers dim incandescent signals by providing half-wave rectified a.c. to the devices. Normally the traffic lamps are powered by switched a.c. line power which has, in virtually all cases, a sinusoidal wave form. Simply rectifying this power allows the traffic signal controller to reduce the average voltage and current to the load in a loss free manner. This technique has been in common use for many years and has become the “defacto” standard dimming technique.

Most LED traffic signals do not work satisfactorily with half wave rectified a.c.; in fact, many simply do not light. Some LED lamp arrays which are equipped with regulated power supplies will illuminate satisfactorily when powered by half wave rectified a.c. current, but they do not dim. The regulated power supplies accept the half wave rectified a.c. line power and treat it merely as a low line voltage and correct for this phenomenon. The voltage impressed across the LED array is kept relatively constant in spite of such input voltage variations thereby keeping the LED luminous output essentially unchanged, i.e. undimmed.

Certain switchmode, regulating power supplies are able to power LED signals satisfactorily from even half wave rectified a.c. power supplies. A half wave detector circuit in the LED signal power supply can determine whether the traffic signal controller is sending a “dimming” command. Upon detection of this half wave signal, the switchmode power supply can be programmed or adjusted to reduce its output voltage to the LED array. By adjusting either the pulse width or the frequency (at constant pulse width) of the switchmode power supply, the output voltage (and/or current) can be reduced in an efficient, nondissipative manner.

Alternatively, the half wave detector can be used to change the average current through the LED array by reducing the effective pulse width of a pulse width modulation controller that drives the LEDs. In either method, the average LED current and intensity are reduced in response to the detection of a half wave rectified input current. In this way, the LED signal is “transparent” to the user who may now utilize the LED device in the same manner as conventional incandescent signals.

As shown in the FIG. 5, a half wave power detector circuit 88 has inputs connected to the inputs of the full wave rectifier 32 at the clamp circuit output lines 26 to monitor the input a.c. power on the power input lines 22 to the power supply 10. The detector 88 has an output connected to a control signal line 90 which is connected to an input of the control I.C. 40. The detector 88 generates a control signal on the line 90 in response to the detection of a half wave dimming signal on the a.c. power lines 22. The control signal is directed to the power supply regulator circuit 38, where it causes the output voltage of the switchmode power supply 10 to be reduced in response to the dimming command. For current regulated power supplies, the average output current to the LED arrays can be reduced to effect dimming. In cases where the LED array is powered by a pulse width modulator, such as the modulator 46, the connection of the line 90 to the control I.C. 40 is eliminated and the output of the detector 88 is connected by a control signal line 92 to an input of the modulator 46 such that the average current delivered to the LED array may be reduced by decreasing the pulse width of the modulator.

All such dimming methods have one key feature in common; the average current through the LED signal 12 is decreased in response to the detection of a half wave dimming signal impressed on the power supply input lines 22. The detection of half wave power by the detector 88 causes the LED power supply 10 to either adjust the output pulse width at constant frequency or adjust the frequency at constant pulse width. The power supply 10 can be any type of power supply which converts a.c. power to d.c. power suitable for illuminating the LED array 12.

The present invention is an apparatus 10 for supplying regulated voltage d.c. electrical power to an LED array including a rectifier means 32 having an input and an output, the rectifier means 32 being responsive to a.c. power at the input for generating rectified d.c. power at the output, a power factor correction converter means 38 having an input connected to the rectifier means 32 output and an output, the power factor correction converter means 38 being responsive to the rectified d.c. power at the power factor correction converter means input for generating regulated voltage, power factor corrected d.c. power at the power factor correction converter means output, and an LED array 12 having an input connected to the power factor correction converter means 38 output for receiving the power factor corrected d.c. power to illuminate the LED array 12. The power factor correction converter means 38 can be a power factor correcting and voltage regulating buck/boost switchmode converter.

The apparatus 10 includes a pulse width modulated modulator means 46 connected to the power factor correction converter means 38 output and the LED array 12 input for modulating the power factor corrected d.c. power and an electromagnetic interference filter means 28 connected to the full wave rectifier means 32 input for preventing conducted interference from feeding back onto a.c. power lines 22 connected to the rectifier means 32 input. The apparatus 10 also includes an adaptive clamp circuit means 24 connected to the rectifier means 32 input for eliminating leakage current problems. The adaptive clamp circuit means 24 has an input adapted to be connected to a pair of a.c. power lines 22, a pair of clamp circuit output lines 26 connected to the adaptive clamp circuit means 24 input, a voltage sensing means 48 connected across the adaptive clamp circuit means 24 input, and a controlled load means 50 connected across the clamp circuit output lines 26 and to the voltage sensing means 48. The voltage sensing means 48 is responsive to a magnitude of a.c. voltage at the adaptive clamp circuit means 24 input lower than a predetermined magnitude for turning on the controlled load means 50 to connect a low impedance load 60 in the controlled load means 50 across the clamp circuit output lines 26 and the voltage sensing means 48 is responsive to a magnitude of the a.c. voltage at the adaptive clamp circuit means 24 input equal to or greater than the predetermined magnitude for turning off the controlled load means 50 to disconnect the low impedance load 60 from the clamp circuit output lines 26.

The apparatus 10 further includes a battery backup means 62 having an input for receiving a.c. power applied to the rectifier means 32 input and having an output at which d.c. power is generated, and a switch-over means 82 connected to the battery backup means 62 output and to the rectifier means 32 input, the battery backup means 62 being responsive to a failure of a.c. power at the battery backup means 62 input for controlling the switch-over means 82 to connect the battery backup means 62 output to the rectifier means 32 input to provide d.c. power to illuminate the LED array 12 and being responsive to a.c. power at the battery backup means 62 input for controlling the switch-over means 82 to disconnect the battery backup means 62 output from the rectifier means 32 input. The switch-over means 82 can be an electromechanical relay. The battery backup means 62 includes a time delay and restoration means 78 responsive to application of a.c. power at the battery backup means 62 input for controlling the switch-over means 82 to disconnect the battery backup means 62 output from the rectifier means 32 input and connect the a.c. power to the rectifier means 32 input after a predetermined time delay. The battery backup means 62 also includes a d.c. power switch-over and flasher means 80 connected to the switch-over means 82 for pulsing the d.c. power at a predetermined rate to flash the LED array 12 and a synchronizing pulse generator means 86 connected to the d.c. power switch-over and flasher means 80 for imposing marker pulses on the d.c. power at a predetermined rate.

The apparatus 10 also includes a half wave power detector means 88 having an input connected to the input of the rectifier means 32 and an output connected to another input of the power factor correction converter means 38, the half wave power detector means being responsive to a dimming signal at the rectifier means input for generating a control signal at said half wave power detector means output and the power factor correction converter means 38 being responsive to the control signal for decreasing the regulated d.c. power to dim the LED array 12. If the apparatus 10 includes the pulse width modulated modulator means 46 connected to the power factor correction converter means 38 output and the LED array 12 input for modulating the regulated voltage d.c. power, the half wave power detector means 88 has its output connected to an input of the pulse width modulated modulator means 46 and is responsive to a dimming signal at the rectifier means input for generating a control signal at the half wave power detector means output and the pulse width modulated modulator means 46 is responsive to the control signal for decreasing the regulated d.c. power to dim the LED array 12.

In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.

Claims (39)

1. An apparatus for supplying regulated voltage d.c. electrical power to an LED array comprising:
a rectifier means (32) having an input and an output, said rectifier means (32) being responsive to a.c. power at said input for generating rectified d.c. power at said output;
a power factor correction converter means (38) having an input connected to said output of said rectifier means (32) and an output, said power factor correction converter means (38) being responsive to said rectified d.c. power at said power factor correction converter means input for generating regulated voltage d.c. power at said power factor correction convener means output; and
an LED array (12) having an input connected to said output of said power factor correction converter means (38) for receiving said regulated voltage d.c. power to illuminate said LED array (12).
2. The apparatus according to claim 1 wherein said power factor correction converter means (38) is a power factor correcting and voltage regulating buck/boost switchmode converter.
3. The apparatus according to claim 1 including a pulse width modulated modulator means (46) connected to said output of said power factor correction converter means (38) and to said input of said LED array (12) for modulating said regulated voltage d.c. power.
4. The apparatus according to claim 1 including an electromagnetic interference filter means (28) connected to said input of said rectifier means (32) for preventing conducted interference from feeding back onto a.c. power lines (22) connected to said rectifier means input.
5. The apparatus according to claim 1 including an adaptive clamp circuit means (24) connected to said input of said rectifier means (32) for eliminating leakage current problems.
6. The apparatus according to claim 5 wherein said adaptive clamp circuit means (24) has an input adapted to be connected to a pair of a.c. power lines (22), a pair of clamp circuit output lines (26) connected to said adaptive clamp circuit means input, a voltage sensing means (48) connected across said input of said adaptive clamp circuit means (24), and a controlled load means (50) connected across said clamp circuit output lines (26) and to said voltage sensing means (48), said voltage sensing means (48) being responsive to a magnitude of a.c. voltage at said adaptive clamp circuit means input lower than a predetermined magnitude for turning on said controlled load means (50) to connect a low impedance load (60) in said controlled load means (50) across said clamp circuit output lines (26) and said voltage sensing means (48) being responsive to a magnitude of the a.c. voltage at said adaptive clamp circuit means input equal to or greater than said predetermined magnitude for turning off said controlled load means (50) to disconnect said low impedance load (60) from said clamp circuit output lines (26).
7. The apparatus according to claim 1 including a battery backup means (62) having an input for receiving a.c. power applied to said input of said rectifier means (32) and having an output at which d.c. power is generated, and a switchover means (82) connected to said output of said battery backup means (62) and to said rectifier means input, said battery backup means (62) being responsive to a failure of a.c. power at said battery backup means input for controlling said switch-over means (82) to connect said output of said battery backup means (62) to said input of said rectifier means (32) to provide d.c. power to illuminate said LED array (12) and being responsive to a.c. power at said battery backup means input for controlling said switch-over means (82) to disconnect said battery backup means output from said rectifier means input.
8. The apparatus according to claim 7 wherein said switch-over means (82) is an electromechanical relay.
9. The apparatus according to claim 7 wherein said battery backup means (62) includes a time delay and restoration means (78) responsive to application of a.c. power at said input of said battery backup means (62) for controlling said switch-over means (82) to disconnect said output of said battery backup means (62) from said input of said full wave rectifier means (32) and connect the a.c. power to said full wave rectifier means input after a predetermined time delay.
10. The apparatus according to claim 7 wherein said battery backup means (62) includes a d.c. power switch-over and flasher means (80) connected to said switch-over means (82) for pulsing said d.c. power at a predetermined rate to flash said LED array (12).
11. The apparatus according to claim 7 wherein said battery backup means (62) includes a synchronizing pulse generator means (86) connected to said d.c. power switchover and flasher means (80) for imposing marker pulses on said d.c. power at a predetermined rate.
12. The apparatus according to claim 1 including a half wave power detector means (88) having an input connected to said input of said rectifier means (32) and an output connected to another input of said power factor correction converter means (38), said half wave power detector means (88) being responsive to a dimming signal at said rectifier means input for generating a control signal at said half wave power detector means output and said power factor correction converter means (38) being responsive to said control signal for decreasing said regulated d.c. power to dim said LED array (12).
13. The apparatus according to claim 1 including a pulse width modulated modulator means (46) connected to said output of said power factor correction converter means (38) and to said input of said LED array (12) for modulating said regulated voltage d.c. power and a half wave power detector means (88) having an input connected to said input of said rectifier means (32) and an output connected to an input of said pulse width modulated modulator means (46), said half wave power detector means being responsive to a dimming signal at said rectifier means input for generating a control signal at said half wave power detector means output and said pulse width modulated modulator means (46) being responsive to said control signal for decreasing said regulated d.c. power to dim said LED array (12).
14. An apparatus for supplying regulated voltage d.c. electrical power to an LED array comprising:
a power supply means (10) having an input and an output, said power supply means (10) being responsive to a.c. power at said input for generating regulated voltage d.c. power at said output to illuminate an LED array (12) connected to said power supply means output; and
a dimming detector means (88) having an input connected to said input of said power supply means (10) and an output connected to another input of said power supply means (10), said dimming detector means (88) being responsive to a dimming signal at said power supply means input for generating a control signal at said dimming detector means output and said power supply means (10) being responsive to said control signal for decreasing said regulated voltage d.c. power to dim the LED array (12).
15. The apparatus according to claim 14 wherein said dimming detector means (88) is a half wave power detector means, said dimming signal is half wave rectified a.c. power and said power supply means (10) includes a rectifier means (32) having an input connected to said power supply means input and an output and a power factor correction converter means (38) having an input connected to said rectifier means output and an output connected to said power supply output, said power factor correction converter means (38) including said another input of said power supply means (10), said power factor correction convener means (38) being responsive to said control signal for decreasing said regulated voltage d.c. power to dim the LED array (12).
16. The apparatus according to claim 14 wherein said dimming detector means (88) is a half wave power detector means, said dimming signal is half wave rectified a.c. power and including a pulse width modulated modulator means (46) connected to said output of said power supply means (10) for modulating said regulated voltage d.c. power, said pulse width modulated modulator means (46) including said another input of said power supply means (10), said pulse width modulated modulator means (46) being responsive to said control signal for decreasing said regulated voltage d.c. power to dim the LED array (12).
17. An apparatus for supplying regulated voltage d.c. electrical power to an LED array comprising:
a rectifier means (32) having an input and an output, said rectifier means (32) being responsive to a.c. power at said input for generating rectified d.c. power at said output;
a power factor correction converter means (38) having an input connected to said output of said rectifier means (32) and an output, said power factor correction converter means (38) being responsive to said rectified d.c. power at said power factor correction converter means input for generating regulated voltage d.c. power at said power factor correction converter means output;
a battery backup means (62) having an input for receiving a.c. power applied to said input of said rectifier means (32) and having an output at which d.c. power is generated; and
a switch-over means (82) connected to said output of said battery backup means (62) and to said input of said rectifier means (32), said battery backup means (62) being responsive to a failure of a.c. power at said battery backup means input for controlling said switchover means (82) to connect said battery backup means output to said rectifier means input to provide d.c. power to said power factor correction converter means (38) to illuminate an LED array connected to said output of said power factor correction converter means (38) and being responsive to a.c. power at said battery backup means input for controlling said switch-over means (82) to disconnect said battery backup means output from said rectifier means input.
18. The apparatus according to claim 17 wherein said power correction converter means (38) is a power factor correcting and voltage regulating buck/boost switchmode converter.
19. The apparatus according to claim 17 including an adaptive clamp circuit means (24) connected to said input of said rectifier means (32) for eliminating leakage current problems, said adaptive clamp circuit means (24) having an input adapted to be connected to a pair of a.c. power lines (22), a pair of clamp circuit output lines (26) connected to said adaptive clamp circuit means input, a voltage sensing means (48) connected across said adaptive clamp circuit means input, and a controlled load means (50) connected across said clamp circuit output lines (26) and to said voltage sensing means (48), said voltage sensing means (48) being responsive to a magnitude of a.c. voltage at said adaptive clamp circuit means input lower than a predetermined magnitude for turning on said controlled load means (50) to connect a low impedance load (60) in said controlled load means (50) across said clamp circuit output lines (26) and said voltage sensing means (48) being responsive to a magnitude of the a.c. voltage at said adaptive clamp circuit means input equal to or greater than said predetermined magnitude for turning off said controlled load means (50) to disconnect said low impedance load (60) from said clamp circuit output lines (26).
20. The apparatus according to claim 17 wherein said battery backup means (62) includes a time delay and restoration means (78) responsive to application of a.c. power at said input of said battery backup means (62) for controlling said switch-over means (82) to disconnect said output of said battery backup means (62) from said input of said rectifier means (32) and connect the a.c. power to said rectifier means input after a predetermined time delay.
21. The apparatus according to claim 17 wherein said battery backup means (62) includes a d.c. power switch-over and flasher means (80) connected to said switch-over means (82) for pulsing said d.c. power at a predetermined rate to flash said LED array (12).
22. The apparatus according to claim 17 Wherein said battery backup means (62) includes a synchronizing pulse generator means (86) connected to said d.c. power switchover and flasher means (80) for imposing marker pulses on said d.c. power at a predetermined rate.
23. An apparatus for supplying regulated voltage d.c. electrical power to an LED array comprising:
a rectifier means (32) having an input and an output, said rectifier means (32) being responsive to a.c. power at said input for generating rectified d.c. power at said output;
a power factor correcting and voltage regulating buck/boost switchmode converter (38) having an input connected to said output of said rectifier means (32) and an output, said switchmode converter (38) being responsive to said rectified d.c. power at said switchmode converter input for generating regulated voltage d.c. power at said switchmode converter output;
an LED array (12) having an input connected to said output of said switchmode converter (38) for receiving said regulated voltage d.c. power to illuminate said LED array (12);
a battery backup means (62) having an input for receiving a.c. power applied to said input of said rectifier means (32) and having an output at which d.c. power is generated; and
a switch-over means (82) connected to said output of said battery backup means (62) and to said input of said rectifier means (32), said battery backup means (62) being responsive to a failure of a.c. power at said battery backup means input for controlling said switchover means (82) to connect said battery backup means output to said rectifier means input to provide d.c. power to said switchmode converter (38) to illuminate said LED array (12) and being responsive to a.c. power at said battery backup means input for controlling said switch-over means (82) to disconnect said battery backup means output from said rectifier means input.
24. A power supply assembly for powering light emitting diodes (LEDs) in an outdoor line-connected signal, comprising:
an electrical input for coupling to a source of a.c. line voltage through a solid state traffic controller switch for providing an electrical input voltage having an operating range with a lower limit voltage sufficient to activate the LEDs when the switch is on;
a rectifier coupled to the electrical input and having a rectifier output;
a line voltage regulating switchmode power supply having a power supply input coupled to the rectifier output and a power supply output;
a plurality of LEDs coupled to the power supply output and having multiple current paths for emitting light in response to the power supply output; and
a conflict monitor compatibility circuit including a low impedance load and a transistor in series connection with the low impedance load, the transistor being biased as a switch having an essentially nonconductive condition whenever the electrical input voltage is at or above the operating range lower limit voltage and an essentially conductive condition if the electrical input voltage drops to a predetermined value below the operating range lower limit voltage, wherein:
the transistor in the essentially nonconductive condition prevents dissipation of power from the power supply output through the low impedance load whenever the electrical input voltage is within the operating range, and
the transistor in the essentially conductive condition couples the low impedance load to the electrical input for shunting leakage current from the solid state traffic controller switch when the switch is off.
25. A power supply assembly for powering light emitting diodes (LEDs) in an outdoor line-connected signal, comprising:
an electrical input for coupling to a source of a.c. line voltage through a solid state traffic controller switch for providing an electrical input voltage having an operating range with a lower limit voltage sufficient to activate the LEDs when the switch is on;
a rectifier coupled to the electrical input and having a rectifier output;
a switchmode power supply for maintaining current and voltage waveforms substantially in phase and for providing a regulated current output with respect to variations in the input line voltage, the power supply having a power supply input coupled to the rectifier output and a power supply output;
a plurality of LEDs coupled to the power supply output and having multiple current paths for emitting light in response to the power supply output; and
a conflict monitor compatibility circuit including a low impedance load and a transistor in series connection with the low impedance load, the transistor being biased as a switch having an essentially nonconductive condition whenever the electrical input voltage is at or above the operating range lower limit voltage and an essentially conductive condition if the electrical input voltage drops to a predetermined value below the operating range lower limit voltage, wherein:
the transistor in the essentially nonconductive condition prevents dissipation of power from the power supply output through the low impedance load whenever the electrical input voltage is within the operating range, and
the transistor in the essentially conductive condition couples the low impedance load to the electrical input for shunting leakage current from the solid state traffic controller switch when the switch is off.
26. A power supply assembly for powering light emitting diodes (LEDs) in an outdoor line-connected signal, comprising:
an electrical input for coupling to a source of a.c. line voltage through a solid state traffic controller switch for providing an electrical input voltage having an operating range with a lower limit voltage sufficient to activate the LEDs when the switch is on;
a rectifier coupled to the electrical input and having a rectifier output;
a switchmode power supply for improving poor power factor, whereby the power supply provides essentially constant current at a power supply output with respect to variations in line voltage input, and whereby current and voltage waveforms are maintained substantially in phase, the power supply having a power supply input coupled to the rectifier output and a power supply output;
a plurality of LEDs coupled to the power supply output and having multiple current paths for emitting light in response to the power supply output; and
a conflict monitor compatibility circuit including a low impedance load and a transistor in series connection with the low impedance load, the transistor being biased as a switch having an essentially nonconductive condition whenever the electrical input voltage is at or above the operating range lower limit voltage and an essentially conductive condition if the electrical input voltage drops to a predetermined value below the operating range lower limit voltage, wherein:
the transistor in the essentially nonconductive condition prevents dissipation of power from the power supply output through the low impedance load whenever the electrical input voltage is within the operating range, and
the transistor in the essentially conductive condition couples the low impedance load to the electrical input for shunting leakage current from the solid state traffic controller switch when the switch is off.
27. The assembly according to claim 24, 25 or 26 wherein the switchmode power supply comprises an integrated circuit power supply.
28. The assembly of claim 27 wherein the integrated circuit power supply comprises a power factor correcting switchmode converter integrated circuit.
29. The assembly according to claim 24, 25 or 26 wherein the plurality of LEDs comprise a plurality of series-parallel connected LEDs arranged in strings.
30. The assembly according to claim 29 wherein the plurality of LEDs comprise a ballast resistor in each string.
31. A conflict monitor compatibility circuit for use in traffic and pedestrian signaling applications, comprising:
a plurality of LEDs for emitting light in response to an electrical input adapted to be coupled to a source of a.c. line voltage through a solid state traffic controller switch for providing an electrical input voltage having an operating range with a lower limit voltage sufficient to activate the LEDs when the switch is on;
a transistor biased as a switch that has an essentially nonconductive condition whenever the electrical input voltage is at or above the operating range lower limit voltage and an essentially conductive condition if the electrical input voltage drops to a predetermined value below the operating range lower limit voltage; and
a low impedance load in series connection with the transistor, wherein:
the transistor in the essentially nonconductive condition prevents dissipation of power through the low impedance load whenever the electrical input voltage is within the operating range, and
the transistor in the essentially conductive condition couples the low impedance load to the electrical input for shunting leakage current from the solid state traffic controller switch when the switch is off.
32. The assembly according to claim 24, 25, or 26, wherein the conflict monitor compatibility circuit further includes a sensor for providing a control output if the electrical input voltage drops below the predetermined value and a control element for switching the transistor to the essentially conductive condition in response to the control output.
33. The assembly according to claim 32, wherein the sensor is a Zener diode that conducts in a reverse direction only at voltages above the predetermined value.
34. The assembly according to claim 33, wherein the control element is a second transistor biased as a switch and having a base coupled to the Zener diode.
35. The assembly according to claim 24, 25, or 26, further comprising an electromagnetic interference filter coupled to the power supply for preventing conducted interference from feeding back onto the a.c. line.
36. The assembly according to claim 24, 25, or 26, further comprising a traffic, pedestrian or rail crossing signal housing enclosing the assembly.
37. The conflict monitor compatibility circuit according claim 31, further comprising a sensor for providing a control output if the electrical input voltage drops below the predetermined value and a control element for switching the transistor to the essentially conductive condition in response to the control output.
38. The conflict monitor compatibility circuit according to claim 37, wherein the sensor is a Zener diode that conducts in a reverse direction only at voltages above the predetermined value.
39. The conflict monitor compatibility circuit according to claim 38, wherein the control element is a second transistor biased as a switch and having a base coupled to the Zener diode.
US09382702 1996-06-27 1999-08-24 Power supply for light emitting diode array Expired - Lifetime USRE42161E1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US08673200 US5661645A (en) 1996-06-27 1996-06-27 Power supply for light emitting diode array
US09382702 USRE42161E1 (en) 1996-06-27 1999-08-24 Power supply for light emitting diode array

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US09382702 USRE42161E1 (en) 1996-06-27 1999-08-24 Power supply for light emitting diode array

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US08673200 Reissue US5661645A (en) 1996-06-27 1996-06-27 Power supply for light emitting diode array

Publications (1)

Publication Number Publication Date
USRE42161E1 true USRE42161E1 (en) 2011-02-22

Family

ID=24701689

Family Applications (2)

Application Number Title Priority Date Filing Date
US08673200 Expired - Lifetime US5661645A (en) 1996-06-27 1996-06-27 Power supply for light emitting diode array
US09382702 Expired - Lifetime USRE42161E1 (en) 1996-06-27 1999-08-24 Power supply for light emitting diode array

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US08673200 Expired - Lifetime US5661645A (en) 1996-06-27 1996-06-27 Power supply for light emitting diode array

Country Status (4)

Country Link
US (2) US5661645A (en)
EP (1) EP0907999A4 (en)
CA (1) CA2259258A1 (en)
WO (1) WO1997050168A1 (en)

Cited By (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100194293A1 (en) * 2007-07-23 2010-08-05 Koninklijke Philips Electronics N.V. Light emitting unit arrangement and control system and method thereof
US20110018450A1 (en) * 2009-07-24 2011-01-27 Kuo-Ching Hsu Light Source Driving Device Capable of Dynamically Keeping Constant Current Sink and Related Method
US20110062887A1 (en) * 2009-09-16 2011-03-17 Novatek Microelectronics Corp. Driving apparatus of light emitting diode and driving method thereof
US8523394B2 (en) 2010-10-29 2013-09-03 Ilumisys, Inc. Mechanisms for reducing risk of shock during installation of light tube
US8596813B2 (en) 2010-07-12 2013-12-03 Ilumisys, Inc. Circuit board mount for LED light tube
US8807785B2 (en) 2008-05-23 2014-08-19 Ilumisys, Inc. Electric shock resistant L.E.D. based light
US8840282B2 (en) 2010-03-26 2014-09-23 Ilumisys, Inc. LED bulb with internal heat dissipating structures
US8866396B2 (en) 2000-02-11 2014-10-21 Ilumisys, Inc. Light tube and power supply circuit
US8870415B2 (en) 2010-12-09 2014-10-28 Ilumisys, Inc. LED fluorescent tube replacement light with reduced shock hazard
US8901823B2 (en) 2008-10-24 2014-12-02 Ilumisys, Inc. Light and light sensor
US8928025B2 (en) 2007-12-20 2015-01-06 Ilumisys, Inc. LED lighting apparatus with swivel connection
US8946996B2 (en) 2008-10-24 2015-02-03 Ilumisys, Inc. Light and light sensor
US9013119B2 (en) 2010-03-26 2015-04-21 Ilumisys, Inc. LED light with thermoelectric generator
US9072171B2 (en) 2011-08-24 2015-06-30 Ilumisys, Inc. Circuit board mount for LED light
US9101026B2 (en) 2008-10-24 2015-08-04 Ilumisys, Inc. Integration of LED lighting with building controls
US20150219700A1 (en) * 2012-05-11 2015-08-06 Osaka City University Power factor measurement device
US9163794B2 (en) 2012-07-06 2015-10-20 Ilumisys, Inc. Power supply assembly for LED-based light tube
US9184518B2 (en) 2012-03-02 2015-11-10 Ilumisys, Inc. Electrical connector header for an LED-based light
US20160043652A1 (en) * 2014-05-28 2016-02-11 Smart Fos, Inc. Systems and Methods for a Transformerless Power Supply to Limit Heat Generation at an Output Transistor Via Time Varying Current Draws
US9267650B2 (en) 2013-10-09 2016-02-23 Ilumisys, Inc. Lens for an LED-based light
US9271367B2 (en) 2012-07-09 2016-02-23 Ilumisys, Inc. System and method for controlling operation of an LED-based light
US9285084B2 (en) 2013-03-14 2016-03-15 Ilumisys, Inc. Diffusers for LED-based lights
US9353939B2 (en) 2008-10-24 2016-05-31 iLumisys, Inc Lighting including integral communication apparatus
US9510400B2 (en) 2014-05-13 2016-11-29 Ilumisys, Inc. User input systems for an LED-based light
US9574717B2 (en) 2014-01-22 2017-02-21 Ilumisys, Inc. LED-based light with addressed LEDs
USD780348S1 (en) 2015-06-01 2017-02-28 Ilumisys, Inc. LED-based light tube
USD781469S1 (en) 2015-07-07 2017-03-14 Ilumisys, Inc. LED light tube
RU2624429C2 (en) * 2012-03-02 2017-07-03 Филипс Лайтинг Холдинг Б.В. Led lighting device and control method of led lighting device
USD815763S1 (en) 2015-07-07 2018-04-17 Ilumisys, Inc. LED-based light tube

Families Citing this family (274)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6590502B1 (en) 1992-10-12 2003-07-08 911Ep, Inc. Led warning signal light and movable support
US6532424B1 (en) 1995-03-13 2003-03-11 Square D Company Electrical fault detection circuit with dual-mode power supply
US6313641B1 (en) 1995-03-13 2001-11-06 Square D Company Method and system for detecting arcing faults and testing such system
US6377427B1 (en) 1995-03-13 2002-04-23 Square D Company Arc fault protected electrical receptacle
US6242993B1 (en) 1995-03-13 2001-06-05 Square D Company Apparatus for use in arcing fault detection systems
US6246556B1 (en) * 1995-03-13 2001-06-12 Square D Company Electrical fault detection system
DE19532142A1 (en) * 1995-08-31 1997-03-06 Siemens Ag Method and apparatus for controlling a four-dimensional vector of a track by means of a value-discrete control element with a limited switching frequency
KR100229604B1 (en) * 1996-11-14 1999-11-15 윤종용 A display monitor power supply apparatus with a power factor correction circuit
US5783909A (en) * 1997-01-10 1998-07-21 Relume Corporation Maintaining LED luminous intensity
US6150771A (en) 1997-06-11 2000-11-21 Precision Solar Controls Inc. Circuit for interfacing between a conventional traffic signal conflict monitor and light emitting diodes replacing a conventional incandescent bulb in the signal
EP0929992B1 (en) * 1997-08-01 2003-08-06 Philips Electronics N.V. Circuit arrangement, and signaling light provided with the circuit arrangement
DE19734750C2 (en) * 1997-08-12 2003-04-30 Reitter & Schefenacker Gmbh Rear light motor vehicles
US20030206411A9 (en) * 1997-08-26 2003-11-06 Dowling Kevin J. Light-emitting diode based products
JPH1167471A (en) * 1997-08-26 1999-03-09 Tec Corp Lighting system
GB2330679B (en) 1997-10-21 2002-04-24 911 Emergency Products Inc Warning signal light
US6107985A (en) * 1997-10-30 2000-08-22 Ericsson Inc. Backlighting circuits including brownout detection circuits responsive to a current through at least one light emitting diode and related methods
US5933308A (en) * 1997-11-19 1999-08-03 Square D Company Arcing fault protection system for a switchgear enclosure
JPH11188914A (en) * 1997-12-25 1999-07-13 Fujitsu Ltd Light emitting diode array
US6570505B1 (en) 1997-12-30 2003-05-27 Gelcore Llc LED lamp with a fault-indicating impedance-changing circuit
US6259996B1 (en) 1998-02-19 2001-07-10 Square D Company Arc fault detection system
US6782329B2 (en) 1998-02-19 2004-08-24 Square D Company Detection of arcing faults using bifurcated wiring system
US6477021B1 (en) 1998-02-19 2002-11-05 Square D Company Blocking/inhibiting operation in an arc fault detection system
US6625550B1 (en) 1998-02-19 2003-09-23 Square D Company Arc fault detection for aircraft
US6621669B1 (en) 1998-02-19 2003-09-16 Square D Company Arc fault receptacle with a feed-through connection
US6236331B1 (en) 1998-02-20 2001-05-22 Newled Technologies Inc. LED traffic light intensity controller
DE69912391T2 (en) * 1998-07-01 2004-08-19 Koninklijke Philips Electronics N.V. Circuit arrangement and signaling light provided therewith
US6275044B1 (en) 1998-07-15 2001-08-14 Square D Company Arcing fault detection system
US6357011B2 (en) * 1998-07-15 2002-03-12 Gateway, Inc. Bus-powered computer peripheral with supplement battery power to overcome bus-power limit
US7931390B2 (en) * 1999-02-12 2011-04-26 Fiber Optic Designs, Inc. Jacketed LED assemblies and light strings containing same
US7066628B2 (en) * 2001-03-29 2006-06-27 Fiber Optic Designs, Inc. Jacketed LED assemblies and light strings containing same
US6072280A (en) * 1998-08-28 2000-06-06 Fiber Optic Designs, Inc. Led light string employing series-parallel block coupling
US6127784A (en) * 1998-08-31 2000-10-03 Dialight Corporation LED driving circuitry with variable load to control output light intensity of an LED
US6191541B1 (en) * 1998-10-05 2001-02-20 Godfrey Engineering, Inc. Solid state tail light for aircraft
US6078148A (en) * 1998-10-09 2000-06-20 Relume Corporation Transformer tap switching power supply for LED traffic signal
DE19848925B4 (en) * 1998-10-23 2010-04-29 Lumino Licht Elektronik Gmbh Method and circuit for driving light-emitting diodes
US6392563B1 (en) 1998-12-16 2002-05-21 9022-6523 Quebec Inc. Traffic light backup system using light-emitting diodes
US6218844B1 (en) 1998-12-16 2001-04-17 Square D Company Method and apparatus for testing an arcing fault circuit interrupter
FI106770B (en) 1999-01-22 2001-03-30 Nokia Mobile Phones Ltd An illustrative electronic device and valaisumenetelmä
WO2000054556A1 (en) * 1999-03-08 2000-09-14 Bebenroth Guenther Circuit arrangement for operating a luminous element
WO2000056121A9 (en) * 1999-03-12 2001-03-15 Koninkl Philips Electronics Nv Circuit arrangement and signal light provided with said circuit arrangement
US6462669B1 (en) * 1999-04-06 2002-10-08 E. P . Survivors Llc Replaceable LED modules
DE19918336A1 (en) * 1999-04-22 2000-11-02 Sickinger Monika Light source of a plurality of series-connected LEDs
US6705745B1 (en) * 1999-06-08 2004-03-16 911Ep, Inc. Rotational led reflector
US6700502B1 (en) 1999-06-08 2004-03-02 911Ep, Inc. Strip LED light assembly for motor vehicle
US6623151B2 (en) 1999-08-04 2003-09-23 911Ep, Inc. LED double light bar and warning light signal
US6367949B1 (en) 1999-08-04 2002-04-09 911 Emergency Products, Inc. Par 36 LED utility lamp
EP1224843A1 (en) 1999-09-29 2002-07-24 Color Kinetics Incorporated Systems and methods for calibrating light output by light-emitting diodes
US7014336B1 (en) 1999-11-18 2006-03-21 Color Kinetics Incorporated Systems and methods for generating and modulating illumination conditions
WO2001045470A1 (en) * 1999-12-14 2001-06-21 Takion Co., Ltd. Power supply and led lamp device
US6566808B1 (en) * 1999-12-22 2003-05-20 General Electric Company Luminescent display and method of making
US7576496B2 (en) * 1999-12-22 2009-08-18 General Electric Company AC powered OLED device
US6362578B1 (en) * 1999-12-23 2002-03-26 Stmicroelectronics, Inc. LED driver circuit and method
US6310445B1 (en) * 2000-01-03 2001-10-30 Dialight Corporation Led indicator disable circuit and led indicator incorporating the led indicator disable circuit
DE60120563D1 (en) 2000-02-03 2006-07-27 Koninkl Philips Electronics Nv Circuit arrangement for a ledbeleuchtungsmodul
GB0002846D0 (en) * 2000-02-08 2000-03-29 Univ Bristol Flashlight
US8093823B1 (en) 2000-02-11 2012-01-10 Altair Engineering, Inc. Light sources incorporating light emitting diodes
JP3396655B2 (en) * 2000-02-29 2003-04-14 株式会社シマノ Bicycle power supply
DE20023993U1 (en) * 2000-03-17 2008-09-25 Tridonicatco Gmbh & Co. Kg Drive circuit for light-emitting diodes
DE10066459B4 (en) * 2000-03-17 2014-05-15 Tridonic Gmbh & Co Kg Drive circuit for light emitting diodes has LED current regulating device that detects LED brightness and/or current and compares it with desired value that can be set by controller
DE10013207B4 (en) 2000-03-17 2014-03-13 Tridonic Gmbh & Co Kg Control of light emitting diodes (LEDs)
US20020027510A1 (en) * 2000-04-28 2002-03-07 Jones Dale G. Apparatus and method for traffic signal flash mode during power outages
US6590343B2 (en) 2000-06-06 2003-07-08 911Ep, Inc. LED compensation circuit
DE10036283A1 (en) * 2000-07-26 2002-02-07 Bosch Gmbh Robert Laser diodes arrangement esp. for optical communication pump module, has laser diodes connected in series
US6547410B1 (en) 2000-07-28 2003-04-15 911 Emergency Products, Inc. LED alley/take-down light
US6642666B1 (en) * 2000-10-20 2003-11-04 Gelcore Company Method and device to emulate a railway searchlight signal with light emitting diodes
US6879263B2 (en) 2000-11-15 2005-04-12 Federal Law Enforcement, Inc. LED warning light and communication system
US8188878B2 (en) 2000-11-15 2012-05-29 Federal Law Enforcement Development Services, Inc. LED light communication system
US6369525B1 (en) * 2000-11-21 2002-04-09 Philips Electronics North America White light-emitting-diode lamp driver based on multiple output converter with output current mode control
CA2336497A1 (en) * 2000-12-20 2002-06-20 Daniel Chevalier Lighting device
JP2002231470A (en) * 2001-02-05 2002-08-16 Pioneer Electronic Corp Light emitting diode driving circuit
US6697402B2 (en) * 2001-07-19 2004-02-24 Analog Modules, Inc. High-power pulsed laser diode driver
US6621235B2 (en) * 2001-08-03 2003-09-16 Koninklijke Philips Electronics N.V. Integrated LED driving device with current sharing for multiple LED strings
US7604361B2 (en) * 2001-09-07 2009-10-20 Litepanels Llc Versatile lighting apparatus and associated kit
US6749310B2 (en) 2001-09-07 2004-06-15 Contrast Lighting Services, Inc. Wide area lighting effects system
GB2383180B (en) * 2001-12-11 2005-05-04 Westinghouse Brake & Signal Signal lamps and apparatus
EP1508157B1 (en) 2002-05-08 2011-11-23 Phoseon Technology, Inc. High efficiency solid-state light source and methods of use and manufacture
US9281001B2 (en) 2004-11-08 2016-03-08 Phoseon Technology, Inc. Methods and systems relating to light sources for use in industrial processes
JP4347794B2 (en) 2002-05-09 2009-10-21 フィリップス ソリッド−ステート ライティング ソリューションズ インコーポレイテッド Led dimming controller
JP2004009825A (en) * 2002-06-05 2004-01-15 Koito Mfg Co Ltd Lighting fixture apparatus for vehicle
US6690146B2 (en) * 2002-06-20 2004-02-10 Fairchild Semiconductor Corporation High efficiency LED driver
JP3715952B2 (en) * 2002-07-05 2005-11-16 キヤノン株式会社 Image reading apparatus
US7439847B2 (en) 2002-08-23 2008-10-21 John C. Pederson Intelligent observation and identification database system
DE10252624A1 (en) * 2002-11-11 2004-05-27 Conti Temic Microelectronic Gmbh Circuit arrangement for operating LED(s) e.g. for motor vehicle, has reactants formed by resistance and capacitor connected into circuit between operating voltage and LED
KR100982167B1 (en) * 2002-12-19 2010-09-14 코닌클리즈케 필립스 일렉트로닉스 엔.브이. Leds driver
US20040141329A1 (en) * 2003-01-20 2004-07-22 Walter Fleischmann Lighting system for aircraft cabins
JP2007524881A (en) * 2003-01-23 2007-08-30 ゲルコアー リミテッド ライアビリティ カンパニー Intellectual led traffic signal module
US6835606B2 (en) * 2003-04-02 2004-12-28 Au Optronics Corporation Low temperature polysilicon thin film transistor and method of forming polysilicon layer of same
US20040257352A1 (en) * 2003-06-18 2004-12-23 Nuelight Corporation Method and apparatus for controlling
US7052152B2 (en) * 2003-10-03 2006-05-30 Philips Lumileds Lighting Company, Llc LCD backlight using two-dimensional array LEDs
WO2005041393A3 (en) * 2003-10-24 2008-01-10 Beniamin Acatrinei Method and system for power factor correction
US7524085B2 (en) * 2003-10-31 2009-04-28 Phoseon Technology, Inc. Series wiring of highly reliable light sources
US7038594B2 (en) * 2004-01-08 2006-05-02 Delphi Technologies, Inc. Led driver current amplifier
US7425075B1 (en) 2004-01-28 2008-09-16 Hubbell David A Optical reflecting material
US20050200292A1 (en) * 2004-02-24 2005-09-15 Naugler W. E.Jr. Emissive display device having sensing for luminance stabilization and user light or touch screen input
US20050200294A1 (en) * 2004-02-24 2005-09-15 Naugler W. E.Jr. Sidelight illuminated flat panel display and touch panel input device
US20050200296A1 (en) * 2004-02-24 2005-09-15 Naugler W. E.Jr. Method and device for flat panel emissive display using shielded or partially shielded sensors to detect user screen inputs
US7659673B2 (en) * 2004-03-15 2010-02-09 Philips Solid-State Lighting Solutions, Inc. Methods and apparatus for providing a controllably variable power to a load
US7569996B2 (en) * 2004-03-19 2009-08-04 Fred H Holmes Omni voltage direct current power supply
US7499003B2 (en) * 2004-03-31 2009-03-03 Electrolux Home Products, Inc. Disappearing interface system
CN1957471A (en) * 2004-04-06 2007-05-02 彩光公司 Color filter integrated with sensor array for flat panel display
CN1981318A (en) * 2004-04-12 2007-06-13 彩光公司 Low power circuits for active matrix emissive displays and methods of operating the same
DE102004020583A1 (en) * 2004-04-27 2005-11-17 Patent-Treuhand-Gesellschaft für elektrische Glühlampen mbH A switching circuit for driving light emitting diodes has an inverse DC voltage changer and current sensing resistor with a zener diode to control the LED current
US20050248515A1 (en) * 2004-04-28 2005-11-10 Naugler W E Jr Stabilized active matrix emissive display
DE102004030536A1 (en) * 2004-06-24 2006-01-12 Siemens Ag A method for determining the risk for a trouble-free operation of a frequency converter
US20060007248A1 (en) * 2004-06-29 2006-01-12 Damoder Reddy Feedback control system and method for operating a high-performance stabilized active-matrix emissive display
DE102004050655A1 (en) 2004-10-18 2006-06-01 Volkswagen Ag Vehicle lighting apparatus and method for controlling a vehicle lighting device
US9313842B2 (en) * 2008-04-08 2016-04-12 Ringdale, Inc. LED lighting controller
US7102902B1 (en) * 2005-02-17 2006-09-05 Ledtronics, Inc. Dimmer circuit for LED
US7378805B2 (en) * 2005-03-22 2008-05-27 Fairchild Semiconductor Corporation Single-stage digital power converter for driving LEDs
US20070001515A1 (en) * 2005-05-18 2007-01-04 Stmicroelectronics Sa Supply of loads of different powers by a D.C./D.C. converter
JP2007080771A (en) * 2005-09-16 2007-03-29 Nec Lighting Ltd Low voltage power supply circuit for lighting, lighting device, and method of outputting power of low voltage power supply for lighting
US7265496B2 (en) * 2005-09-23 2007-09-04 Fiber Optic Designs, Inc. Junction circuit for LED lighting chain
EP1932394B1 (en) * 2005-09-27 2016-04-27 Koninklijke Philips N.V. Led landscape lighting fixture
US7276858B2 (en) 2005-10-28 2007-10-02 Fiber Optic Designs, Inc. Decorative lighting string with stacked rectification
US20070103337A1 (en) * 2005-11-09 2007-05-10 Honeywell International Inc. Backup traffic control systems and methods
US7872430B2 (en) 2005-11-18 2011-01-18 Cree, Inc. Solid state lighting panels with variable voltage boost current sources
US7250730B1 (en) * 2006-01-17 2007-07-31 Fiber Optic Designs, Inc. Unique lighting string rectification
ES2647096T3 (en) * 2006-02-10 2017-12-19 Philips Lighting North America Corporation Methods and apparatus for power delivery with controlled high power factor using a single stage load switching
JP4533328B2 (en) * 2006-02-28 2010-09-01 株式会社リコー Charge controlling semiconductor integrated circuit, a charging device and a secondary battery connection detection method using the charge controlling semiconductor integrated circuit
US8044815B2 (en) * 2006-03-03 2011-10-25 O2Micro Inc Systems and methods for battery status indication
US20070236155A1 (en) * 2006-04-11 2007-10-11 Beyond Innovation Technology Co., Ltd. Power converter for led module and related devices thereof
US20080018261A1 (en) * 2006-05-01 2008-01-24 Kastner Mark A LED power supply with options for dimming
US7649327B2 (en) * 2006-05-22 2010-01-19 Permlight Products, Inc. System and method for selectively dimming an LED
WO2007139975A1 (en) * 2006-05-26 2007-12-06 Lumificient Technologies, Llc Current regulator apparatus and methods
US7852010B2 (en) * 2006-05-31 2010-12-14 Cree, Inc. Lighting device and method of lighting
EP2573925A1 (en) * 2006-09-13 2013-03-27 Cree, Inc. Circuit For Supplying Electrical Power
CN101523978B (en) * 2006-11-03 2011-04-06 奥斯兰姆有限公司 A circuit for driving light sources and related method
WO2008060623A3 (en) * 2006-11-15 2008-08-21 Kevin Joseph Hathaway High output led based illuminator that replaces ccfls for lcd backlights
EP1953448A1 (en) * 2007-02-05 2008-08-06 Excellence Opto Inc. Improved led lighting string employing rectified and filtered device
EP2127486B1 (en) * 2007-02-26 2012-06-06 Philips Intellectual Property & Standards GmbH Driving a lighting device
US7667408B2 (en) 2007-03-12 2010-02-23 Cirrus Logic, Inc. Lighting system with lighting dimmer output mapping
US7288902B1 (en) * 2007-03-12 2007-10-30 Cirrus Logic, Inc. Color variations in a dimmable lighting device with stable color temperature light sources
EP2140732B1 (en) * 2007-03-30 2015-11-04 Holdip Limited Improvements relating to lighting systems
US7859196B2 (en) 2007-04-25 2010-12-28 American Bright Lighting, Inc. Solid state lighting apparatus
WO2008137460A3 (en) * 2007-05-07 2010-01-28 Koninklijke Philips Electronics N V High power factor led-based lighting apparatus and methods
US8049709B2 (en) 2007-05-08 2011-11-01 Cree, Inc. Systems and methods for controlling a solid state lighting panel
US7663326B2 (en) * 2007-05-22 2010-02-16 Msilica Incorporated Temperature dependant LED current controller
US20080317475A1 (en) 2007-05-24 2008-12-25 Federal Law Enforcement Development Services, Inc. Led light interior room and building communication system
US9100124B2 (en) 2007-05-24 2015-08-04 Federal Law Enforcement Development Services, Inc. LED Light Fixture
US9414458B2 (en) 2007-05-24 2016-08-09 Federal Law Enforcement Development Services, Inc. LED light control assembly and system
US9258864B2 (en) 2007-05-24 2016-02-09 Federal Law Enforcement Development Services, Inc. LED light control and management system
US9294198B2 (en) 2007-05-24 2016-03-22 Federal Law Enforcement Development Services, Inc. Pulsed light communication key
FR2919457A1 (en) * 2007-07-27 2009-01-30 Marc Didier Patrick Pettmann Switching power supply device for powering and controlling LEDs in e.g. street lighting, has adjustment channels adjusting different current by colors of LEDs, where one of channels is adjusted to nominal current
DE202007011973U1 (en) * 2007-08-27 2009-01-02 Ruppel, Stefan LED cluster arrangement with constant current switch
US7862204B2 (en) * 2007-10-25 2011-01-04 Pervaiz Lodhie LED light
US7784967B2 (en) * 2007-10-30 2010-08-31 Pervaiz Lodhie Loop LED light
US7712918B2 (en) 2007-12-21 2010-05-11 Altair Engineering , Inc. Light distribution using a light emitting diode assembly
USD631567S1 (en) 2008-01-11 2011-01-25 Pervaiz Lodhie LED bulb
US8115419B2 (en) 2008-01-23 2012-02-14 Cree, Inc. Lighting control device for controlling dimming, lighting device including a control device, and method of controlling lighting
US8432108B2 (en) * 2008-04-30 2013-04-30 Lsi Industries, Inc. Solid state lighting, driver circuits, and related software
US7952293B2 (en) * 2008-04-30 2011-05-31 Lsi Industries, Inc. Power factor correction and driver circuits
CN102057754A (en) * 2008-05-06 2011-05-11 皇家飞利浦电子股份有限公司 Apparatus for coupling power source to lamp
US8004210B2 (en) * 2008-05-28 2011-08-23 Harmgardt Hans L G LED replacement for low voltage lamps
US7812550B2 (en) * 2008-05-28 2010-10-12 Revlite Technologies Inc. LED replacement for low voltage lamps
USD613885S1 (en) 2008-06-10 2010-04-13 Pervaiz Lodhie Two-stage LED light module
USD614318S1 (en) 2008-06-10 2010-04-20 Pervaiz Lodhie LED light module
USD613886S1 (en) 2008-06-10 2010-04-13 Pervaiz Lodhie LED light module with cutouts
US7976196B2 (en) 2008-07-09 2011-07-12 Altair Engineering, Inc. Method of forming LED-based light and resulting LED-based light
US7946729B2 (en) 2008-07-31 2011-05-24 Altair Engineering, Inc. Fluorescent tube replacement having longitudinally oriented LEDs
US8207711B2 (en) * 2008-08-15 2012-06-26 Analog Modules, Inc. Biphase laser diode driver and method
EP2329478A4 (en) * 2008-08-15 2014-04-23 Ge Lighting Solutions Llc Traffic led lamp with internal circuit backup system
US8729870B2 (en) 2008-08-15 2014-05-20 Analog Modules, Inc. Biphase laser diode driver and method
EP2319279A4 (en) 2008-08-21 2014-12-03 American Bright Lighting Inc Led light engine
US8674626B2 (en) 2008-09-02 2014-03-18 Ilumisys, Inc. LED lamp failure alerting system
KR101001241B1 (en) * 2008-09-05 2010-12-17 서울반도체 주식회사 Ac led dimmer and dimming method thereby
US8256924B2 (en) 2008-09-15 2012-09-04 Ilumisys, Inc. LED-based light having rapidly oscillating LEDs
CA2747294A1 (en) 2008-10-08 2010-04-15 Holdip Limited Improvements relating to power adaptors
DE202008013397U1 (en) * 2008-10-09 2010-03-25 Tridonicatco Schweiz Ag A drive circuit for a semiconductor light source (LED)
US8653984B2 (en) 2008-10-24 2014-02-18 Ilumisys, Inc. Integration of LED lighting control with emergency notification systems
US8444292B2 (en) 2008-10-24 2013-05-21 Ilumisys, Inc. End cap substitute for LED-based tube replacement light
US7875869B1 (en) 2008-11-01 2011-01-25 Kamyar Shadan Apparatus for sanitizing feet of persons entering a home
US8614595B2 (en) * 2008-11-14 2013-12-24 Beniamin Acatrinei Low cost ultra versatile mixed signal controller circuit
US8174213B2 (en) * 2008-12-05 2012-05-08 Richard Landry Gray Universal input voltage light emitting device
US8233301B1 (en) * 2008-12-20 2012-07-31 Sensorlink Corporation Impedance dropping dc power supply having an impedance controlled converter
US9326346B2 (en) 2009-01-13 2016-04-26 Terralux, Inc. Method and device for remote sensing and control of LED lights
US8358085B2 (en) 2009-01-13 2013-01-22 Terralux, Inc. Method and device for remote sensing and control of LED lights
US8556452B2 (en) 2009-01-15 2013-10-15 Ilumisys, Inc. LED lens
US8362710B2 (en) 2009-01-21 2013-01-29 Ilumisys, Inc. Direct AC-to-DC converter for passive component minimization and universal operation of LED arrays
US8664880B2 (en) 2009-01-21 2014-03-04 Ilumisys, Inc. Ballast/line detection circuit for fluorescent replacement lamps
US8890773B1 (en) 2009-04-01 2014-11-18 Federal Law Enforcement Development Services, Inc. Visible light transceiver glasses
US8004861B2 (en) * 2009-04-16 2011-08-23 Fsp Technology Inc. Parameter configuration method for elements of power factor correction function converter
WO2010127366A3 (en) * 2009-05-01 2011-01-20 Fulham Co. Ltd. Supplemental, backup or emergency lighting systems and methods
US8330381B2 (en) 2009-05-14 2012-12-11 Ilumisys, Inc. Electronic circuit for DC conversion of fluorescent lighting ballast
US8217591B2 (en) 2009-05-28 2012-07-10 Cree, Inc. Power source sensing dimming circuits and methods of operating same
US8299695B2 (en) 2009-06-02 2012-10-30 Ilumisys, Inc. Screw-in LED bulb comprising a base having outwardly projecting nodes
US20120170328A1 (en) * 2009-06-19 2012-07-05 Robertson Transformer Co. Multimodal LED Power Supply With Wide Compliance Voltage and Safety Controlled Output
US8421366B2 (en) 2009-06-23 2013-04-16 Ilumisys, Inc. Illumination device including LEDs and a switching power control system
KR101711901B1 (en) * 2009-08-14 2017-03-03 온스 이노베이션스, 인코포레이티드 Spectral shift control for dimmable ac led lighting
US8373363B2 (en) 2009-08-14 2013-02-12 Once Innovations, Inc. Reduction of harmonic distortion for LED loads
CN102012009B (en) * 2009-09-08 2013-03-13 富准精密工业(深圳)有限公司 Lamp with balance sensing unit
US8901845B2 (en) 2009-09-24 2014-12-02 Cree, Inc. Temperature responsive control for lighting apparatus including light emitting devices providing different chromaticities and related methods
US9713211B2 (en) 2009-09-24 2017-07-18 Cree, Inc. Solid state lighting apparatus with controllable bypass circuits and methods of operation thereof
US9068719B2 (en) 2009-09-25 2015-06-30 Cree, Inc. Light engines for lighting devices
US9353933B2 (en) 2009-09-25 2016-05-31 Cree, Inc. Lighting device with position-retaining element
US8602579B2 (en) 2009-09-25 2013-12-10 Cree, Inc. Lighting devices including thermally conductive housings and related structures
US8777449B2 (en) 2009-09-25 2014-07-15 Cree, Inc. Lighting devices comprising solid state light emitters
US9285103B2 (en) 2009-09-25 2016-03-15 Cree, Inc. Light engines for lighting devices
US9464801B2 (en) 2009-09-25 2016-10-11 Cree, Inc. Lighting device with one or more removable heat sink elements
US9155174B2 (en) 2009-09-30 2015-10-06 Cirrus Logic, Inc. Phase control dimming compatible lighting systems
US8492988B2 (en) 2009-10-07 2013-07-23 Lutron Electronics Co., Inc. Configurable load control device for light-emitting diode light sources
US9030120B2 (en) * 2009-10-20 2015-05-12 Cree, Inc. Heat sinks and lamp incorporating same
US9217542B2 (en) 2009-10-20 2015-12-22 Cree, Inc. Heat sinks and lamp incorporating same
US8334656B2 (en) * 2009-11-03 2012-12-18 Msi, Llc Replaceable lighting unit with adjustable output intensity and optional capability for reporting usage information, and method of operating same
EP2501393B1 (en) * 2009-11-17 2016-07-27 Terralux, Inc. Led power-supply detection and control
EP2534407A2 (en) 2010-02-12 2012-12-19 Cree, Inc. Lighting devices that comprise one or more solid state light emitters
US9518715B2 (en) * 2010-02-12 2016-12-13 Cree, Inc. Lighting devices that comprise one or more solid state light emitters
US8773007B2 (en) 2010-02-12 2014-07-08 Cree, Inc. Lighting devices that comprise one or more solid state light emitters
US20110267821A1 (en) 2010-02-12 2011-11-03 Cree, Inc. Lighting device with heat dissipation elements
CN102782391B (en) 2010-02-12 2016-08-03 科锐公司 The solid state lighting apparatus and assembling method
US8531127B2 (en) * 2010-02-24 2013-09-10 Cal Poly Pomona Foundation, Inc Computer controlled power supply assembly for a LED array
CA2794512A1 (en) 2010-03-26 2011-09-29 David L. Simon Led light tube with dual sided light distribution
CN101860200A (en) * 2010-04-27 2010-10-13 华为技术有限公司 Power-down retaining circuit, method and power supply system
DE102010028230A1 (en) * 2010-04-27 2011-10-27 Tridonic Jennersdorf Gmbh Circuit arrangement for operating LEDs
US8476836B2 (en) 2010-05-07 2013-07-02 Cree, Inc. AC driven solid state lighting apparatus with LED string including switched segments
US20110273918A1 (en) * 2010-05-10 2011-11-10 Hon Hai Precision Industry Co., Ltd. Power device
EP2398298A3 (en) * 2010-05-24 2012-03-14 ADB Airfield Solutions LLC Power supply for an airfield LED sign
US8454193B2 (en) 2010-07-08 2013-06-04 Ilumisys, Inc. Independent modules for LED fluorescent light tube replacement
EP2405717A1 (en) * 2010-07-09 2012-01-11 Chiu-Min Lin LED lamp brightness adjusting circuit connectable to AC power and LED lighting device using the same
US9307601B2 (en) 2010-08-17 2016-04-05 Koninklijke Philips N.V. Input voltage sensing for a switching power converter and a triac-based dimmer
US8729811B2 (en) 2010-07-30 2014-05-20 Cirrus Logic, Inc. Dimming multiple lighting devices by alternating energy transfer from a magnetic storage element
US8536799B1 (en) 2010-07-30 2013-09-17 Cirrus Logic, Inc. Dimmer detection
US9433047B2 (en) * 2010-08-23 2016-08-30 Active-Semi, Inc. Single inductor multiple LED string driver
EP2609790A2 (en) 2010-08-24 2013-07-03 Cirrus Logic, Inc. Multi-mode dimmer interfacing including attach state control
KR20140018835A (en) 2010-08-27 2014-02-13 아메리칸 브라이트 라이팅, 아이엔씨. Solid state lighting driver with thdi bypass circuit
KR20120059129A (en) * 2010-11-30 2012-06-08 삼성전기주식회사 Circuit for discharging ac power
US20120146539A1 (en) * 2010-12-10 2012-06-14 Scott Arthur Riesebosch Jitter detection and compensation circuit for led lamps
US8192039B1 (en) * 2010-12-16 2012-06-05 MOCO Enterprises LLC Light emitting diode backup systems and methods
CA2824756C (en) 2011-01-14 2014-12-23 Federal Law Enforcement Development Services, Inc. Method of providing lumens and tracking of lumen consumption
US8558407B2 (en) 2011-01-25 2013-10-15 Man-D-Tec, Inc. Elevator emergency LED lighting power supply assembly
US8996190B2 (en) 2011-03-01 2015-03-31 Michael Lamar Williams Method and apparatus for controlling electrical loads to provide positive damping of power grid oscillation
WO2012119244A1 (en) * 2011-03-07 2012-09-13 Led Roadway Lighting Ltd. Single stage power factor corrected flyback converter with constant current multi-channel output power supply for led applications
EP2684284B1 (en) * 2011-03-09 2017-11-15 Philips Lighting Holding B.V. Adjustable fly-back or buck-boost converter
US8680787B2 (en) 2011-03-15 2014-03-25 Lutron Electronics Co., Inc. Load control device for a light-emitting diode light source
GB201105512D0 (en) * 2011-03-31 2011-05-18 Litonics Ltd Lighting device
JP6032764B2 (en) * 2011-04-08 2016-11-30 フィリップス ライティング ホールディング ビー ヴィ Load, in particular a driving device and a driving method for driving a led assembly
US20120268936A1 (en) 2011-04-19 2012-10-25 Cree, Inc. Heat sink structures, lighting elements and lamps incorporating same, and methods of making same
US9839083B2 (en) 2011-06-03 2017-12-05 Cree, Inc. Solid state lighting apparatus and circuits including LED segments configured for targeted spectral power distribution and methods of operating the same
US8686659B2 (en) * 2011-06-27 2014-04-01 Osram Sylvania Inc. Multiple lamp lighting level ballast for series connected lamps
EP2737774B1 (en) * 2011-07-25 2017-06-28 Philips Lighting Holding B.V. System and method for implementing mains-signal-based dimming of a solid state lighting module
US8742671B2 (en) 2011-07-28 2014-06-03 Cree, Inc. Solid state lighting apparatus and methods using integrated driver circuitry
US9510413B2 (en) 2011-07-28 2016-11-29 Cree, Inc. Solid state lighting apparatus and methods of forming
US9270143B1 (en) * 2011-08-02 2016-02-23 Cooper Technologies Company Systems, methods, and devices for providing drive electronics with a backup power supply for an LED luminaire
CN102413609B (en) * 2011-11-04 2013-11-13 王坤 Low-power illuminating system with LED (light-emitting diode) lamps
US9066403B2 (en) 2011-11-29 2015-06-23 GE Lighting Solutions, LLC LED lamp with half wave dimming
WO2013090904A1 (en) 2011-12-16 2013-06-20 Terralux, Inc. System and methods of applying bleed circuits in led lamps
US9554445B2 (en) 2012-02-03 2017-01-24 Cree, Inc. Color point and/or lumen output correction device, lighting system with color point and/or lumen output correction, lighting device, and methods of lighting
WO2013126836A8 (en) 2012-02-29 2014-08-07 Cirrus Logic, Inc. Mixed load current compensation for led lighting
GB201204106D0 (en) * 2012-03-08 2012-04-18 Tridonic Uk Ltd Lamp unit power supply system
JP5576891B2 (en) * 2012-03-13 2014-08-20 オムロンオートモーティブエレクトロニクス株式会社 Led lighting and disconnection detection control unit
JP5576892B2 (en) * 2012-03-13 2014-08-20 オムロンオートモーティブエレクトロニクス株式会社 Led lighting and disconnection detection control unit
JP2013206710A (en) * 2012-03-28 2013-10-07 Toshiba Lighting & Technology Corp Lighting control device and illumination control device
CN103475238A (en) * 2012-06-08 2013-12-25 鸿富锦精密工业(深圳)有限公司 Voltage conversion circuit
US9184661B2 (en) 2012-08-27 2015-11-10 Cirrus Logic, Inc. Power conversion with controlled capacitance charging including attach state control
US9894724B2 (en) 2013-01-16 2018-02-13 Lind Equipment Ltd. Portable lighting system
US9035494B2 (en) 2013-03-07 2015-05-19 Man-D-Tec, Inc. Elevator interior illumination
WO2014160096A1 (en) 2013-03-13 2014-10-02 Federal Law Enforcement Development Services, Inc. Led light control and management system
US9696022B2 (en) 2013-03-14 2017-07-04 Mandy Holdings Lllp Downward illumination assembly
US9200784B2 (en) 2013-03-15 2015-12-01 Man-D-Tec, Inc. Downward illumination assembly
JP2014182883A (en) * 2013-03-18 2014-09-29 Toshiba Lighting & Technology Corp Serial load control device and marker lamp device
WO2014174159A1 (en) 2013-04-24 2014-10-30 Societe D'etudes Et D'economies En Eclairage, Se3 Device for supplying direct current for a set of led-based lighting devices used in industrial lighting and tertiary lighting
US9455783B2 (en) 2013-05-06 2016-09-27 Federal Law Enforcement Development Services, Inc. Network security and variable pulse wave form with continuous communication
US9547348B2 (en) 2013-05-10 2017-01-17 Walter Kidde Portable Equipment Inc. Reactive power supply
US9265119B2 (en) 2013-06-17 2016-02-16 Terralux, Inc. Systems and methods for providing thermal fold-back to LED lights
DE202013009404U1 (en) 2013-06-20 2013-12-13 Andrej I. Shchedrin Converter an AC voltage into a DC voltage
DE102013106444A1 (en) 2013-06-20 2014-12-24 Andrej I. Shchedrin Converter an AC voltage into a DC voltage
US9468046B2 (en) 2013-07-20 2016-10-11 Lunera Lighting, Inc. Hybrid power architecture for controlling a lighting system
US9933144B2 (en) 2013-09-20 2018-04-03 Man-D-Tec, Inc. Light fixture mounting assembly
US9453639B2 (en) 2013-09-24 2016-09-27 Mandy Holdings Lllp Rectilinear light source for elevator interior
GB201322022D0 (en) 2013-12-12 2014-01-29 Led Lighting Consultants Ltd Improvements relating to power adaptors
FR3019694B1 (en) * 2014-04-07 2016-04-15 Daniel Toussaint supply electric device
USD738834S1 (en) * 2014-07-29 2015-09-15 Jianhui Xie Driver circuit integrated LED module
US9755448B2 (en) 2014-10-10 2017-09-05 Revolution Lighting Technologies, Inc. LED luminaire with integrated battery backup
GB201421220D0 (en) * 2014-11-28 2015-01-14 Neatebox Ltd And Neate Gavin A Traffic control system apparatus
US20160276949A1 (en) * 2015-03-20 2016-09-22 Hubbell Incorporated Universal input electronic transformer

Citations (166)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1662348A (en) 1925-09-12 1928-03-13 George W Stricker Changeable sign and traffic signal
US2503574A (en) 1947-05-06 1950-04-11 Walkolite Company Inc Combined pedestrian traffic signal and advertising device
CA786714A (en) 1968-06-04 The B. F. Goodrich Company Method and apparatus for making a pneumatic tire
US3421009A (en) 1966-06-14 1969-01-07 Felix P Caruthers Temperature compensated photosensor system
US3456155A (en) 1965-04-30 1969-07-15 Advance Data Systems Corp Photosensitive circuit for controlling the intensity of a lamp
US3473084A (en) 1967-12-06 1969-10-14 Automatic Power Inc Constant intensity lamp control with an optical feedback control
US3500455A (en) 1968-07-05 1970-03-10 Minnesota Mining & Mfg Light responsive electrical lamp dimming means
US3611177A (en) 1969-05-16 1971-10-05 Energy Conversion Devices Inc Electroluminescent relaxation oscillator for dc operation
US3670202A (en) 1970-07-31 1972-06-13 Nasa Ultrastable calibrated light source
US3705316A (en) 1971-12-27 1972-12-05 Nasa Temperature compensated light source using a light emitting diode
US3787752A (en) 1972-07-28 1974-01-22 Us Navy Intensity control for light-emitting diode display
US3872301A (en) 1974-03-15 1975-03-18 Schwarzer Gmbh Fritz Automatically temperature-compensated electro-optic circuit
US3873905A (en) 1974-03-18 1975-03-25 Ltv Aerospace Corp Control circuit to provide shunt path for leakage current
US3952242A (en) 1969-04-11 1976-04-20 Ricoh Co., Ltd. Automatic voltage regulator with optical feedback
US3959711A (en) 1974-12-09 1976-05-25 Technology Development Corporation Pulse width modulated power supplies
US4001637A (en) 1975-06-12 1977-01-04 Lutron Electronics Co., Inc. Lamp ballast
US4012686A (en) 1971-03-18 1977-03-15 Optotechnik, Gmbh Power supply for illuminated instrument
US4037271A (en) 1976-12-03 1977-07-19 Boschert Associates Switching regulator power supply
US4052644A (en) 1975-03-19 1977-10-04 Rollei-Werke Franke & Heidecke Electronic flash unit with operational signal
US4090189A (en) 1976-05-20 1978-05-16 General Electric Company Brightness control circuit for LED displays
US4101808A (en) 1975-09-30 1978-07-18 Bell & Howell Company Lamp control circuit
US4109307A (en) 1977-05-04 1978-08-22 Gte Sylvania Incorporated High power factor conversion circuitry
US4135116A (en) 1978-01-16 1979-01-16 The United States Of America As Represented By The Secretary Of The Navy Constant illumination control system
US4182977A (en) 1978-06-01 1980-01-08 Trw Inc. Constant output light emitting device
US4190836A (en) 1976-11-15 1980-02-26 Hitachi, Ltd. Dynamic drive circuit for light-emitting diodes
US4190795A (en) 1977-09-09 1980-02-26 Coberly & Associates Constant intensity light source
US4211955A (en) 1978-03-02 1980-07-08 Ray Stephen W Solid state lamp
US4238707A (en) 1978-01-20 1980-12-09 Thomson-Csf Power supply system for a semiconductor light source
US4247854A (en) 1979-05-09 1981-01-27 Ncr Corporation Gas panel with improved circuit for display operation
US4275335A (en) 1979-03-28 1981-06-23 Minolta Camera Kabushiki Kaisha Constant light intensity electronic flash device
US4298869A (en) 1978-06-29 1981-11-03 Zaidan Hojin Handotai Kenkyu Shinkokai Light-emitting diode display
US4319164A (en) 1979-07-30 1982-03-09 Midland-Ross Corporation Power factor compensating electroluminescent lamp DC/AC inverter
US4323895A (en) 1979-05-11 1982-04-06 Regie Nationale Des Usines Renault Display device for dashboard of automobile
US4329625A (en) 1978-07-24 1982-05-11 Zaidan Hojin Handotai Kenkyu Shinkokai Light-responsive light-emitting diode display
US4342947A (en) 1977-10-14 1982-08-03 Bloyd Jon A Light indicating system having light emitting diodes and power reduction circuit
US4347461A (en) 1980-10-23 1982-08-31 Robert L. Elving Incident illumination responsive light control
US4367464A (en) 1979-05-29 1983-01-04 Mitsubishi Denki Kabushiki Kaisha Large scale display panel apparatus
US4386281A (en) 1981-01-15 1983-05-31 Mostek Corporation Circuit for detecting loss of supply voltage
US4388578A (en) 1980-07-07 1983-06-14 Cynex Manufacturing Corporation Power factor controller
US4423478A (en) 1981-07-20 1983-12-27 Xerox Corporation Phase controlled regulated power supply
US4467246A (en) 1980-08-28 1984-08-21 Canon Kabushiki Kaisha Light quantity controller and input device
US4492899A (en) 1981-08-18 1985-01-08 Indicator Controls Corporation Solid state regulated power supply system for cold cathode luminous tube
US4495445A (en) 1983-06-06 1985-01-22 General Electric Company Brightness control for a vacuum fluorescent display
US4568857A (en) * 1982-11-09 1986-02-04 Honeywell Ltd. Fluorescent light controller
US4571506A (en) 1984-03-28 1986-02-18 At&T Bell Laboratories LED Driver Circuit
US4581655A (en) 1983-03-31 1986-04-08 Toshiba Denzai Kabushiki Kaisha Video display apparatus
DE3535204A1 (en) 1984-10-04 1986-04-17 Nystrom Karl G Traffic signalling device or other similar light signalling device
US4587459A (en) 1983-12-27 1986-05-06 Blake Frederick H Light-sensing, light fixture control system
US4598198A (en) 1984-05-21 1986-07-01 Banner Engineering Corp. Automatic power control for modulated LED photoelectric devices
US4645997A (en) 1985-03-13 1987-02-24 Kollmorgen Technologies Corporation Transient free solid state automatic power factor correction
US4656365A (en) 1985-07-12 1987-04-07 Westinghouse Electric Corp. Solid state power controller leakage current shunt circuit
US4673865A (en) 1986-04-04 1987-06-16 Motorola, Inc. Charge coupled LED driver circuit
US4677366A (en) 1986-05-12 1987-06-30 Pioneer Research, Inc. Unity power factor power supply
US4712000A (en) 1983-10-21 1987-12-08 Canon Kabushiki Kaisha Rotary encoder with source-adjacent light sampling and control
US4717868A (en) 1984-06-08 1988-01-05 American Microsystems, Inc. Uniform intensity led driver circuit
US4719552A (en) 1985-11-22 1988-01-12 U.S. Philips Corporation AC-DC converter triggered by variable frequency pulses
US4729076A (en) 1984-11-15 1988-03-01 Tsuzawa Masami Signal light unit having heat dissipating function
DE3644347A1 (en) 1986-12-19 1988-06-30 Siemens Ag Method for operating a light-emitting diode
US4825351A (en) 1986-11-26 1989-04-25 Kabushiki Kaisha Toshiba AC-DC converting apparatus having power factor improving circuit utilizing a photocoupler
US4837495A (en) 1987-10-13 1989-06-06 Astec U.S.A. (Hk) Limited Current mode converter with controlled slope compensation
US4845489A (en) 1985-12-23 1989-07-04 Chrysler Motors Corporation Electroluminescent display drive circuitry
US4849683A (en) 1988-12-07 1989-07-18 Motorola, Inc. Lamp driver circuit with controlled power over a range of power supply voltages
US4855890A (en) 1987-06-24 1989-08-08 Reliance Comm/Tec Corporation Power factor correction circuit
US4868669A (en) 1986-07-31 1989-09-19 Ricoh Company, Ltd. Integrated input/output device
US4891569A (en) 1982-08-20 1990-01-02 Versatex Industries Power factor controller
US4902936A (en) 1986-11-20 1990-02-20 Sharp Kabushiki Kaisha Light adjusting apparatus
US4929871A (en) 1986-06-16 1990-05-29 Gerfast Sten R Transformerless current-limiting circuit
US4933605A (en) 1987-06-12 1990-06-12 Etta Industries, Inc. Fluorescent dimming ballast utilizing a resonant sine wave power converter
US4943902A (en) 1987-11-23 1990-07-24 Viteq Corporation AC to DC power converter and method with integrated line current control for improving power factor
US4954822A (en) 1988-09-02 1990-09-04 Arnold Borenstein Traffic signal using light-emitting diodes
US4958108A (en) 1989-02-14 1990-09-18 Avtech Corporation Universal fluorescent lamp ballast
US4969282A (en) 1988-12-02 1990-11-13 Eberhart Wolfgang R Glass block illuminated display
US4970437A (en) 1989-07-10 1990-11-13 Motorola Lighting, Inc. Chopper for conventional ballast system
US4974141A (en) 1988-05-18 1990-11-27 Viteq Corporation AC to DC power converter with input current waveform control for buck-boost regualtion of output
US4980812A (en) 1989-11-09 1990-12-25 Exide Electronics Uninterrupted power supply system having improved power factor correction circuit
US4982139A (en) 1989-04-03 1991-01-01 At&T Bell Laboratories Method and apparatus for controlling light intensity
US4988889A (en) 1989-07-03 1991-01-29 Self-Powered Lighting, Inc. Power source for emergency lighting systems
US5001620A (en) 1988-07-25 1991-03-19 Astec International Limited Power factor improvement
US5003454A (en) 1990-01-09 1991-03-26 North American Philips Corporation Power supply with improved power factor correction
US5004947A (en) 1986-01-21 1991-04-02 Nilssen Ole K Fluorescent lamp ballast with high power factor
US5006975A (en) 1989-11-03 1991-04-09 Cherry Semiconductor Corporation Power factor correction circuit
US5008599A (en) 1990-02-14 1991-04-16 Usi Lighting, Inc. Power factor correction circuit
US5012162A (en) 1990-04-13 1991-04-30 Unisys Corporation Light emitting diode transmitter circuit with temperature compensation
US5012161A (en) 1989-01-05 1991-04-30 General Electric Company Power factor correction circuit
US5019952A (en) 1989-11-20 1991-05-28 General Electric Company AC to DC power conversion circuit with low harmonic distortion
US5023521A (en) 1989-12-18 1991-06-11 Radionic Industries, Inc. Lamp ballast system
US5030887A (en) 1990-01-29 1991-07-09 Guisinger John E High frequency fluorescent lamp exciter
US5041766A (en) 1987-08-03 1991-08-20 Ole K. Nilssen Power-factor-controlled electronic ballast
US5045758A (en) 1990-04-25 1991-09-03 Hildebrand Cleve R Solid state regulated power supply for luminescent lamp
US5047912A (en) 1990-03-09 1991-09-10 International Rectifier Corporation Four-terminal unity power factor electronic rectifier
US5048033A (en) 1990-09-04 1991-09-10 Coherent, Inc. Method and apparatus for controlling the power supply of a laser operating in a pulse mode
US5075601A (en) 1990-04-25 1991-12-24 Hildebrand Cleve R Power supply dynamic load for traffic and pedestrian signal
US5089748A (en) 1990-06-13 1992-02-18 Delco Electronics Corporation Photo-feedback drive system
US5095305A (en) 1988-08-31 1992-03-10 Toshiba Lighting & Technology Corporation Large display apparatus using discharge lamps and discharge lamp load circuit for the large display apparatus
US5113337A (en) 1991-02-08 1992-05-12 General Electric Company High power factor power supply
US5134345A (en) 1991-10-31 1992-07-28 General Electric Company Feedback system for stabilizing the arc discharge of a high intensity discharge lamp
US5134355A (en) 1990-12-31 1992-07-28 Texas Instruments Incorporated Power factor correction control for switch-mode power converters
US5135160A (en) 1990-08-17 1992-08-04 Opticon, Inc. Portable bar code reader utilizing pulsed LED array
US5146398A (en) 1991-08-20 1992-09-08 Led Corporation N.V. Power factor correction device provided with a frequency and amplitude modulated boost converter
US5212428A (en) 1990-10-01 1993-05-18 Koito Manufacturing Co., Ltd. Lighting circuit for vehicular discharge lamp
US5235504A (en) 1991-03-15 1993-08-10 Emerson Electric Co. High power-factor converter for motor drives and power supplies
US5258692A (en) 1992-06-02 1993-11-02 Appliance Control Technology, Inc. Electronic ballast high power factor for gaseous discharge lamps
US5272327A (en) 1992-05-26 1993-12-21 Compaq Computer Corporation Constant brightness liquid crystal display backlight control system
CA2142332A1 (en) 1992-08-13 1994-03-03 Meinrad Machler Spectroscopic systems for the analysis of small and very small quantities of substances
US5293077A (en) 1988-02-29 1994-03-08 Hitachi, Ltd. Power switching circuit
US5309062A (en) 1992-05-20 1994-05-03 Progressive Technology In Lighting, Inc. Three-way compact fluorescent lamp system utilizing an electronic ballast having a variable frequency oscillator
US5313187A (en) 1989-10-11 1994-05-17 Bell Sports, Inc. Battery-powered flashing superluminescent light emitting diode safety warning light
US5317307A (en) 1992-05-22 1994-05-31 Intel Corporation Method for pulse width modulation of LEDs with power demand load leveling
US5321600A (en) 1992-10-26 1994-06-14 Hughes Aircraft Company Delta connected three phase AC-DC converter with power factor correction circuits
US5340974A (en) 1991-12-09 1994-08-23 Hughes Aircraft Company Polychromatic source calibration by one or more spectrally filtered photodetector currents
US5349172A (en) 1992-02-27 1994-09-20 Alex Roustaei Optical scanning head
US5354977A (en) 1992-02-27 1994-10-11 Alex Roustaei Optical scanning head
US5359276A (en) 1993-05-12 1994-10-25 Unitrode Corporation Automatic gain selection for high power factor
US5359274A (en) 1992-08-20 1994-10-25 North American Philips Corporation Active offset for power factor controller
US5363020A (en) 1993-02-05 1994-11-08 Systems And Service International, Inc. Electronic power controller
US5367223A (en) 1991-12-30 1994-11-22 Hewlett-Packard Company Fluoresent lamp current level controller
US5371667A (en) 1993-06-14 1994-12-06 Fuji Electrochemical Co., Ltd. Electric power supply
US5391976A (en) 1993-07-28 1995-02-21 At&T Corp. Power factor control arrangement for an OLS based on quarter cycle averaged power flow
US5396153A (en) 1993-12-09 1995-03-07 Motorola Lighting, Inc. Protection circuit for electronic ballasts which use charge pump power factor correction
US5408084A (en) 1993-02-18 1995-04-18 United Parcel Service Of America, Inc. Method and apparatus for illumination and imaging of a surface using 2-D LED array
US5408403A (en) 1992-08-25 1995-04-18 General Electric Company Power supply circuit with power factor correction
US5420779A (en) 1993-03-04 1995-05-30 Dell Usa, L.P. Inverter current load detection and disable circuit
EP0660648A1 (en) 1993-12-27 1995-06-28 Illinois Tool Works Inc. Dimming circuit for a LED
US5430635A (en) 1993-12-06 1995-07-04 Bertonee, Inc. High power factor electronic transformer system for gaseous discharge tubes
US5436529A (en) 1993-02-01 1995-07-25 Bobel; Andrzej A. Control and protection circuit for electronic ballast
US5436553A (en) 1993-09-24 1995-07-25 Tektronix, Inc. Optical power conversion
US5438586A (en) 1992-11-30 1995-08-01 Canon Kabushiki Kaisha Apparatus with light-emitting element and method for producing it
US5446440A (en) * 1993-01-06 1995-08-29 Lederlite Corporation Emergency sign and control circuit
CA2142132A1 (en) 1994-03-03 1995-09-04 James C. Johnson Methods and apparatus for illumination of signs utilizing light emitting diodes
US5449981A (en) 1989-03-10 1995-09-12 Bruce Industries, Inc. Electronic ballast and power controller
US5463280A (en) 1994-03-03 1995-10-31 National Service Industries, Inc. Light emitting diode retrofit lamp
US5489771A (en) 1993-10-15 1996-02-06 University Of Virginia Patent Foundation LED light standard for photo- and videomicroscopy
US5495147A (en) 1994-04-15 1996-02-27 Lanzisera; Vincent A. LED light string system
US5510680A (en) 1978-03-20 1996-04-23 Nilssen; Ole K. Electronic ballast with special voltage waveforms
US5532918A (en) 1992-06-10 1996-07-02 Digital Equipment Corporation High power factor switched DC power supply
US5539198A (en) 1993-09-28 1996-07-23 Rockwell International Corporation Uniform sensitivity light curtain
US5550463A (en) 1993-05-20 1996-08-27 Coveley; Michael Power supply connected in parallel with solid state switch for phase control of average power to a load
US5563781A (en) 1993-11-24 1996-10-08 Integrated Technology Corporation Dual-mode power converter
US5572416A (en) 1994-06-09 1996-11-05 Lucent Technologies Inc. Isolated input current sense means for high power factor rectifier
US5572112A (en) 1994-05-23 1996-11-05 Fujitsu Limited Power supply unit
US5587895A (en) 1994-09-07 1996-12-24 Harkins; Michael T. Electrical power supply with single output from range of input voltages
US5614812A (en) 1995-03-16 1997-03-25 Franklin Electric Co. Inc. Power supply with power factor correction
US5615101A (en) 1994-12-29 1997-03-25 Lucent Technologies Inc. Power converter with high power factor
US5633629A (en) 1995-02-08 1997-05-27 Hochstein; Peter A. Traffic information system using light emitting diodes
US5635902A (en) 1994-11-16 1997-06-03 Hochstein; Peter A. L.E.D. enhanced bus stop sign
US5638265A (en) 1993-08-24 1997-06-10 Gabor; George Low line harmonic AC to DC power supply
US5646512A (en) 1995-08-30 1997-07-08 Beckwith; Robert W. Multifunction adaptive controls for tapswitches and capacitors
US5650694A (en) 1995-03-31 1997-07-22 Philips Electronics North America Corporation Lamp controller with lamp status detection and safety circuitry
US5654705A (en) 1996-09-06 1997-08-05 Houten; Ronald Van Apparatus for prompting pedestrians
US5661374A (en) 1994-12-14 1997-08-26 Astronics Corporation LED light strip with brightness/current draw control circuitry
US5663719A (en) 1993-04-29 1997-09-02 Electro-Tech's LED traffic signal light with automatic low-line voltage compensating circuit
US5684368A (en) 1996-06-10 1997-11-04 Motorola Smart driver for an array of LEDs
US5719474A (en) 1996-06-14 1998-02-17 Loral Corporation Fluorescent lamps with current-mode driver control
US5734229A (en) * 1995-11-29 1998-03-31 Bavaro; Joseph P. Back-up electrical system for portable table lamps
US5764039A (en) 1995-11-15 1998-06-09 Samsung Electronics Co., Ltd. Power factor correction circuit having indirect input voltage sensing
US5765940A (en) 1995-10-31 1998-06-16 Dialight Corporation LED-illuminated stop/tail lamp assembly
US5767979A (en) 1996-05-22 1998-06-16 Samsung Electronics Co., Ltd. Led light source apparatus for scanner and method for controlling the same
US5782555A (en) 1996-06-27 1998-07-21 Hochstein; Peter A. Heat dissipating L.E.D. traffic light
US5783909A (en) 1997-01-10 1998-07-21 Relume Corporation Maintaining LED luminous intensity
US5785418A (en) 1996-06-27 1998-07-28 Hochstein; Peter A. Thermally protected LED array
US5845987A (en) 1996-10-08 1998-12-08 Painter; John M. Illuminated accessory and device
US5852348A (en) 1997-05-08 1998-12-22 Lin; Wen-Juei Christmas tree ornamental lighting system
US5857767A (en) 1996-09-23 1999-01-12 Relume Corporation Thermal management system for L.E.D. arrays
US5929568A (en) 1997-07-08 1999-07-27 Korry Electronics Co. Incandescent bulb luminance matching LED circuit
US5936599A (en) * 1995-01-27 1999-08-10 Reymond; Welles AC powered light emitting diode array circuits for use in traffic signal displays
US5934798A (en) 1997-03-07 1999-08-10 Truck-Lite Co., Inc. Light emitting diode license lamp

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4277728A (en) * 1978-05-08 1981-07-07 Stevens Luminoptics Power supply for a high intensity discharge or fluorescent lamp
CN1012244B (en) * 1987-02-20 1991-03-27 株式会社东芝 Uninterruptible power source equipment
DE4340604A1 (en) * 1993-08-25 1995-03-02 Tridonic Bauelemente Ges Mbh Electronic ballast for supplying a load, such as a lamp
DE4433552B4 (en) * 1994-09-06 2004-01-15 Marx, Peter, Prof. Dr.-Ing. Electronic RF dimmer for high and low voltage light bulbs

Patent Citations (167)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA786714A (en) 1968-06-04 The B. F. Goodrich Company Method and apparatus for making a pneumatic tire
US1662348A (en) 1925-09-12 1928-03-13 George W Stricker Changeable sign and traffic signal
US2503574A (en) 1947-05-06 1950-04-11 Walkolite Company Inc Combined pedestrian traffic signal and advertising device
US3456155A (en) 1965-04-30 1969-07-15 Advance Data Systems Corp Photosensitive circuit for controlling the intensity of a lamp
US3421009A (en) 1966-06-14 1969-01-07 Felix P Caruthers Temperature compensated photosensor system
US3473084A (en) 1967-12-06 1969-10-14 Automatic Power Inc Constant intensity lamp control with an optical feedback control
US3500455A (en) 1968-07-05 1970-03-10 Minnesota Mining & Mfg Light responsive electrical lamp dimming means
US3952242A (en) 1969-04-11 1976-04-20 Ricoh Co., Ltd. Automatic voltage regulator with optical feedback
US3611177A (en) 1969-05-16 1971-10-05 Energy Conversion Devices Inc Electroluminescent relaxation oscillator for dc operation
US3670202A (en) 1970-07-31 1972-06-13 Nasa Ultrastable calibrated light source
US4012686A (en) 1971-03-18 1977-03-15 Optotechnik, Gmbh Power supply for illuminated instrument
US3705316A (en) 1971-12-27 1972-12-05 Nasa Temperature compensated light source using a light emitting diode
US3787752A (en) 1972-07-28 1974-01-22 Us Navy Intensity control for light-emitting diode display
US3872301A (en) 1974-03-15 1975-03-18 Schwarzer Gmbh Fritz Automatically temperature-compensated electro-optic circuit
US3873905A (en) 1974-03-18 1975-03-25 Ltv Aerospace Corp Control circuit to provide shunt path for leakage current
US3959711A (en) 1974-12-09 1976-05-25 Technology Development Corporation Pulse width modulated power supplies
US4052644A (en) 1975-03-19 1977-10-04 Rollei-Werke Franke & Heidecke Electronic flash unit with operational signal
US4001637A (en) 1975-06-12 1977-01-04 Lutron Electronics Co., Inc. Lamp ballast
US4101808A (en) 1975-09-30 1978-07-18 Bell & Howell Company Lamp control circuit
US4090189A (en) 1976-05-20 1978-05-16 General Electric Company Brightness control circuit for LED displays
US4190836A (en) 1976-11-15 1980-02-26 Hitachi, Ltd. Dynamic drive circuit for light-emitting diodes
US4037271A (en) 1976-12-03 1977-07-19 Boschert Associates Switching regulator power supply
US4109307A (en) 1977-05-04 1978-08-22 Gte Sylvania Incorporated High power factor conversion circuitry
US4190795A (en) 1977-09-09 1980-02-26 Coberly & Associates Constant intensity light source
US4342947A (en) 1977-10-14 1982-08-03 Bloyd Jon A Light indicating system having light emitting diodes and power reduction circuit
US4135116A (en) 1978-01-16 1979-01-16 The United States Of America As Represented By The Secretary Of The Navy Constant illumination control system
US4238707A (en) 1978-01-20 1980-12-09 Thomson-Csf Power supply system for a semiconductor light source
US4211955A (en) 1978-03-02 1980-07-08 Ray Stephen W Solid state lamp
US5510680A (en) 1978-03-20 1996-04-23 Nilssen; Ole K. Electronic ballast with special voltage waveforms
US4182977A (en) 1978-06-01 1980-01-08 Trw Inc. Constant output light emitting device
US4298869A (en) 1978-06-29 1981-11-03 Zaidan Hojin Handotai Kenkyu Shinkokai Light-emitting diode display
US4329625A (en) 1978-07-24 1982-05-11 Zaidan Hojin Handotai Kenkyu Shinkokai Light-responsive light-emitting diode display
US4275335A (en) 1979-03-28 1981-06-23 Minolta Camera Kabushiki Kaisha Constant light intensity electronic flash device
US4247854A (en) 1979-05-09 1981-01-27 Ncr Corporation Gas panel with improved circuit for display operation
US4323895A (en) 1979-05-11 1982-04-06 Regie Nationale Des Usines Renault Display device for dashboard of automobile
US4367464A (en) 1979-05-29 1983-01-04 Mitsubishi Denki Kabushiki Kaisha Large scale display panel apparatus
US4319164A (en) 1979-07-30 1982-03-09 Midland-Ross Corporation Power factor compensating electroluminescent lamp DC/AC inverter
US4388578A (en) 1980-07-07 1983-06-14 Cynex Manufacturing Corporation Power factor controller
US4467246A (en) 1980-08-28 1984-08-21 Canon Kabushiki Kaisha Light quantity controller and input device
US4347461A (en) 1980-10-23 1982-08-31 Robert L. Elving Incident illumination responsive light control
US4386281A (en) 1981-01-15 1983-05-31 Mostek Corporation Circuit for detecting loss of supply voltage
US4423478A (en) 1981-07-20 1983-12-27 Xerox Corporation Phase controlled regulated power supply
US4492899A (en) 1981-08-18 1985-01-08 Indicator Controls Corporation Solid state regulated power supply system for cold cathode luminous tube
US4891569A (en) 1982-08-20 1990-01-02 Versatex Industries Power factor controller
US4568857A (en) * 1982-11-09 1986-02-04 Honeywell Ltd. Fluorescent light controller
US4581655A (en) 1983-03-31 1986-04-08 Toshiba Denzai Kabushiki Kaisha Video display apparatus
US4495445A (en) 1983-06-06 1985-01-22 General Electric Company Brightness control for a vacuum fluorescent display
US4712000A (en) 1983-10-21 1987-12-08 Canon Kabushiki Kaisha Rotary encoder with source-adjacent light sampling and control
US4587459A (en) 1983-12-27 1986-05-06 Blake Frederick H Light-sensing, light fixture control system
US4571506A (en) 1984-03-28 1986-02-18 At&T Bell Laboratories LED Driver Circuit
US4598198A (en) 1984-05-21 1986-07-01 Banner Engineering Corp. Automatic power control for modulated LED photoelectric devices
US4717868A (en) 1984-06-08 1988-01-05 American Microsystems, Inc. Uniform intensity led driver circuit
DE3535204A1 (en) 1984-10-04 1986-04-17 Nystrom Karl G Traffic signalling device or other similar light signalling device
US4729076A (en) 1984-11-15 1988-03-01 Tsuzawa Masami Signal light unit having heat dissipating function
US4645997A (en) 1985-03-13 1987-02-24 Kollmorgen Technologies Corporation Transient free solid state automatic power factor correction
US4656365A (en) 1985-07-12 1987-04-07 Westinghouse Electric Corp. Solid state power controller leakage current shunt circuit
US4719552A (en) 1985-11-22 1988-01-12 U.S. Philips Corporation AC-DC converter triggered by variable frequency pulses
US4845489A (en) 1985-12-23 1989-07-04 Chrysler Motors Corporation Electroluminescent display drive circuitry
US5004947A (en) 1986-01-21 1991-04-02 Nilssen Ole K Fluorescent lamp ballast with high power factor
US4673865A (en) 1986-04-04 1987-06-16 Motorola, Inc. Charge coupled LED driver circuit
US4677366A (en) 1986-05-12 1987-06-30 Pioneer Research, Inc. Unity power factor power supply
US4929871A (en) 1986-06-16 1990-05-29 Gerfast Sten R Transformerless current-limiting circuit
US4868669A (en) 1986-07-31 1989-09-19 Ricoh Company, Ltd. Integrated input/output device
US4902936A (en) 1986-11-20 1990-02-20 Sharp Kabushiki Kaisha Light adjusting apparatus
US4825351A (en) 1986-11-26 1989-04-25 Kabushiki Kaisha Toshiba AC-DC converting apparatus having power factor improving circuit utilizing a photocoupler
DE3644347A1 (en) 1986-12-19 1988-06-30 Siemens Ag Method for operating a light-emitting diode
US4933605A (en) 1987-06-12 1990-06-12 Etta Industries, Inc. Fluorescent dimming ballast utilizing a resonant sine wave power converter
US4855890A (en) 1987-06-24 1989-08-08 Reliance Comm/Tec Corporation Power factor correction circuit
US5041766A (en) 1987-08-03 1991-08-20 Ole K. Nilssen Power-factor-controlled electronic ballast
US4837495A (en) 1987-10-13 1989-06-06 Astec U.S.A. (Hk) Limited Current mode converter with controlled slope compensation
US4943902A (en) 1987-11-23 1990-07-24 Viteq Corporation AC to DC power converter and method with integrated line current control for improving power factor
US5293077A (en) 1988-02-29 1994-03-08 Hitachi, Ltd. Power switching circuit
US4974141A (en) 1988-05-18 1990-11-27 Viteq Corporation AC to DC power converter with input current waveform control for buck-boost regualtion of output
US5001620A (en) 1988-07-25 1991-03-19 Astec International Limited Power factor improvement
US5095305A (en) 1988-08-31 1992-03-10 Toshiba Lighting & Technology Corporation Large display apparatus using discharge lamps and discharge lamp load circuit for the large display apparatus
US4954822A (en) 1988-09-02 1990-09-04 Arnold Borenstein Traffic signal using light-emitting diodes
US4969282A (en) 1988-12-02 1990-11-13 Eberhart Wolfgang R Glass block illuminated display
US4849683A (en) 1988-12-07 1989-07-18 Motorola, Inc. Lamp driver circuit with controlled power over a range of power supply voltages
US5012161A (en) 1989-01-05 1991-04-30 General Electric Company Power factor correction circuit
US4958108A (en) 1989-02-14 1990-09-18 Avtech Corporation Universal fluorescent lamp ballast
US5449981A (en) 1989-03-10 1995-09-12 Bruce Industries, Inc. Electronic ballast and power controller
US4982139A (en) 1989-04-03 1991-01-01 At&T Bell Laboratories Method and apparatus for controlling light intensity
US4988889A (en) 1989-07-03 1991-01-29 Self-Powered Lighting, Inc. Power source for emergency lighting systems
US4970437A (en) 1989-07-10 1990-11-13 Motorola Lighting, Inc. Chopper for conventional ballast system
US5313187A (en) 1989-10-11 1994-05-17 Bell Sports, Inc. Battery-powered flashing superluminescent light emitting diode safety warning light
US5006975A (en) 1989-11-03 1991-04-09 Cherry Semiconductor Corporation Power factor correction circuit
US4980812A (en) 1989-11-09 1990-12-25 Exide Electronics Uninterrupted power supply system having improved power factor correction circuit
US5019952A (en) 1989-11-20 1991-05-28 General Electric Company AC to DC power conversion circuit with low harmonic distortion
US5023521A (en) 1989-12-18 1991-06-11 Radionic Industries, Inc. Lamp ballast system
US5003454A (en) 1990-01-09 1991-03-26 North American Philips Corporation Power supply with improved power factor correction
US5030887A (en) 1990-01-29 1991-07-09 Guisinger John E High frequency fluorescent lamp exciter
US5008599A (en) 1990-02-14 1991-04-16 Usi Lighting, Inc. Power factor correction circuit
US5047912A (en) 1990-03-09 1991-09-10 International Rectifier Corporation Four-terminal unity power factor electronic rectifier
US5012162A (en) 1990-04-13 1991-04-30 Unisys Corporation Light emitting diode transmitter circuit with temperature compensation
US5075601A (en) 1990-04-25 1991-12-24 Hildebrand Cleve R Power supply dynamic load for traffic and pedestrian signal
US5045758A (en) 1990-04-25 1991-09-03 Hildebrand Cleve R Solid state regulated power supply for luminescent lamp
US5089748A (en) 1990-06-13 1992-02-18 Delco Electronics Corporation Photo-feedback drive system
US5135160A (en) 1990-08-17 1992-08-04 Opticon, Inc. Portable bar code reader utilizing pulsed LED array
US5048033A (en) 1990-09-04 1991-09-10 Coherent, Inc. Method and apparatus for controlling the power supply of a laser operating in a pulse mode
US5212428A (en) 1990-10-01 1993-05-18 Koito Manufacturing Co., Ltd. Lighting circuit for vehicular discharge lamp
US5134355A (en) 1990-12-31 1992-07-28 Texas Instruments Incorporated Power factor correction control for switch-mode power converters
US5113337A (en) 1991-02-08 1992-05-12 General Electric Company High power factor power supply
US5235504A (en) 1991-03-15 1993-08-10 Emerson Electric Co. High power-factor converter for motor drives and power supplies
US5146398A (en) 1991-08-20 1992-09-08 Led Corporation N.V. Power factor correction device provided with a frequency and amplitude modulated boost converter
US5134345A (en) 1991-10-31 1992-07-28 General Electric Company Feedback system for stabilizing the arc discharge of a high intensity discharge lamp
US5340974A (en) 1991-12-09 1994-08-23 Hughes Aircraft Company Polychromatic source calibration by one or more spectrally filtered photodetector currents
US5367223A (en) 1991-12-30 1994-11-22 Hewlett-Packard Company Fluoresent lamp current level controller
US5354977A (en) 1992-02-27 1994-10-11 Alex Roustaei Optical scanning head
US5349172A (en) 1992-02-27 1994-09-20 Alex Roustaei Optical scanning head
US5309062A (en) 1992-05-20 1994-05-03 Progressive Technology In Lighting, Inc. Three-way compact fluorescent lamp system utilizing an electronic ballast having a variable frequency oscillator
US5317307A (en) 1992-05-22 1994-05-31 Intel Corporation Method for pulse width modulation of LEDs with power demand load leveling
US5272327A (en) 1992-05-26 1993-12-21 Compaq Computer Corporation Constant brightness liquid crystal display backlight control system
US5258692A (en) 1992-06-02 1993-11-02 Appliance Control Technology, Inc. Electronic ballast high power factor for gaseous discharge lamps
US5532918A (en) 1992-06-10 1996-07-02 Digital Equipment Corporation High power factor switched DC power supply
CA2142332A1 (en) 1992-08-13 1994-03-03 Meinrad Machler Spectroscopic systems for the analysis of small and very small quantities of substances
US5359274A (en) 1992-08-20 1994-10-25 North American Philips Corporation Active offset for power factor controller
US5408403A (en) 1992-08-25 1995-04-18 General Electric Company Power supply circuit with power factor correction
US5321600A (en) 1992-10-26 1994-06-14 Hughes Aircraft Company Delta connected three phase AC-DC converter with power factor correction circuits
US5438586A (en) 1992-11-30 1995-08-01 Canon Kabushiki Kaisha Apparatus with light-emitting element and method for producing it
US5446440A (en) * 1993-01-06 1995-08-29 Lederlite Corporation Emergency sign and control circuit
US5436529A (en) 1993-02-01 1995-07-25 Bobel; Andrzej A. Control and protection circuit for electronic ballast
US5363020A (en) 1993-02-05 1994-11-08 Systems And Service International, Inc. Electronic power controller
US5408084A (en) 1993-02-18 1995-04-18 United Parcel Service Of America, Inc. Method and apparatus for illumination and imaging of a surface using 2-D LED array
US5420779A (en) 1993-03-04 1995-05-30 Dell Usa, L.P. Inverter current load detection and disable circuit
US5663719A (en) 1993-04-29 1997-09-02 Electro-Tech's LED traffic signal light with automatic low-line voltage compensating circuit
US5359276A (en) 1993-05-12 1994-10-25 Unitrode Corporation Automatic gain selection for high power factor
US5550463A (en) 1993-05-20 1996-08-27 Coveley; Michael Power supply connected in parallel with solid state switch for phase control of average power to a load
US5371667A (en) 1993-06-14 1994-12-06 Fuji Electrochemical Co., Ltd. Electric power supply
US5391976A (en) 1993-07-28 1995-02-21 At&T Corp. Power factor control arrangement for an OLS based on quarter cycle averaged power flow
US5638265A (en) 1993-08-24 1997-06-10 Gabor; George Low line harmonic AC to DC power supply
US5436553A (en) 1993-09-24 1995-07-25 Tektronix, Inc. Optical power conversion
US5539198A (en) 1993-09-28 1996-07-23 Rockwell International Corporation Uniform sensitivity light curtain
US5489771A (en) 1993-10-15 1996-02-06 University Of Virginia Patent Foundation LED light standard for photo- and videomicroscopy
US5563781A (en) 1993-11-24 1996-10-08 Integrated Technology Corporation Dual-mode power converter
US5430635A (en) 1993-12-06 1995-07-04 Bertonee, Inc. High power factor electronic transformer system for gaseous discharge tubes
US5396153A (en) 1993-12-09 1995-03-07 Motorola Lighting, Inc. Protection circuit for electronic ballasts which use charge pump power factor correction
US5459478A (en) 1993-12-27 1995-10-17 Illinois Tool Works, Inc. Aircraft cockpit switch circuitry
EP0660648A1 (en) 1993-12-27 1995-06-28 Illinois Tool Works Inc. Dimming circuit for a LED
CA2142132A1 (en) 1994-03-03 1995-09-04 James C. Johnson Methods and apparatus for illumination of signs utilizing light emitting diodes
US5463280A (en) 1994-03-03 1995-10-31 National Service Industries, Inc. Light emitting diode retrofit lamp
US5495147A (en) 1994-04-15 1996-02-27 Lanzisera; Vincent A. LED light string system
US5572112A (en) 1994-05-23 1996-11-05 Fujitsu Limited Power supply unit
US5572416A (en) 1994-06-09 1996-11-05 Lucent Technologies Inc. Isolated input current sense means for high power factor rectifier
US5587895A (en) 1994-09-07 1996-12-24 Harkins; Michael T. Electrical power supply with single output from range of input voltages
US5635902A (en) 1994-11-16 1997-06-03 Hochstein; Peter A. L.E.D. enhanced bus stop sign
US5661374A (en) 1994-12-14 1997-08-26 Astronics Corporation LED light strip with brightness/current draw control circuitry
US5615101A (en) 1994-12-29 1997-03-25 Lucent Technologies Inc. Power converter with high power factor
US5936599A (en) * 1995-01-27 1999-08-10 Reymond; Welles AC powered light emitting diode array circuits for use in traffic signal displays
US5633629A (en) 1995-02-08 1997-05-27 Hochstein; Peter A. Traffic information system using light emitting diodes
US5614812A (en) 1995-03-16 1997-03-25 Franklin Electric Co. Inc. Power supply with power factor correction
US5650694A (en) 1995-03-31 1997-07-22 Philips Electronics North America Corporation Lamp controller with lamp status detection and safety circuitry
US5646512A (en) 1995-08-30 1997-07-08 Beckwith; Robert W. Multifunction adaptive controls for tapswitches and capacitors
US5765940A (en) 1995-10-31 1998-06-16 Dialight Corporation LED-illuminated stop/tail lamp assembly
US5764039A (en) 1995-11-15 1998-06-09 Samsung Electronics Co., Ltd. Power factor correction circuit having indirect input voltage sensing
US5734229A (en) * 1995-11-29 1998-03-31 Bavaro; Joseph P. Back-up electrical system for portable table lamps
US5767979A (en) 1996-05-22 1998-06-16 Samsung Electronics Co., Ltd. Led light source apparatus for scanner and method for controlling the same
US5684368A (en) 1996-06-10 1997-11-04 Motorola Smart driver for an array of LEDs
US5719474A (en) 1996-06-14 1998-02-17 Loral Corporation Fluorescent lamps with current-mode driver control
US5782555A (en) 1996-06-27 1998-07-21 Hochstein; Peter A. Heat dissipating L.E.D. traffic light
US5785418A (en) 1996-06-27 1998-07-28 Hochstein; Peter A. Thermally protected LED array
US5654705A (en) 1996-09-06 1997-08-05 Houten; Ronald Van Apparatus for prompting pedestrians
US5857767A (en) 1996-09-23 1999-01-12 Relume Corporation Thermal management system for L.E.D. arrays
US5845987A (en) 1996-10-08 1998-12-08 Painter; John M. Illuminated accessory and device
US5783909A (en) 1997-01-10 1998-07-21 Relume Corporation Maintaining LED luminous intensity
US5934798A (en) 1997-03-07 1999-08-10 Truck-Lite Co., Inc. Light emitting diode license lamp
US5852348A (en) 1997-05-08 1998-12-22 Lin; Wen-Juei Christmas tree ornamental lighting system
US5929568A (en) 1997-07-08 1999-07-27 Korry Electronics Co. Incandescent bulb luminance matching LED circuit

Non-Patent Citations (96)

* Cited by examiner, † Cited by third party
Title
"Hi-Flux LED Modules-433 Series Traffic Signals," Dialight Specification Sheet, undated, http://www.dialight.com/pdf/TrafficSignals/MDTS433EXCAL001_A-W.pdf, last visited Oct. 12, 2006.
"Hi-Flux LED Modules—433 Series Traffic Signals," Dialight Specification Sheet, undated, http://www.dialight.com/pdf/TrafficSignals/MDTS433EXCAL001_A-W.pdf, last visited Oct. 12, 2006.
12'' LED Red Arrow Indication, by McCain Traffic Supply pp. 3-4.
12″ LED Red Arrow Indication, by McCain Traffic Supply pp. 3-4.
4.3 Transformer-Isolated Switching Power Supply Topologies, pp. E11549-E11550.
6th European Conference on Power Electronics and Applications, by EPE Association, vol. 2, Sep. 20, 1995. pp. 003211-003216.
8'' and 12'' LED Red Ball Indication, by McCain Traffic Supply pp. 5-6.
8″ and 12″ LED Red Ball Indication, by McCain Traffic Supply pp. 5-6.
A New Control Strategy to Achieve Sinusoidal Line Current in a Cascade Buck-Boost Converter, by Mohammed C. Ghanem et al., pp. E11435-E11445.
A New Very High Voltage Smartmos IC Combines Power Factor Control With Internation Off-Line Startup, pp. E11534-E11542.
Affirmative Defenses and Counterclaim Defendant, Excolux's Answer to Plaintiff's Complaint, Case No. 98-72360, Jul. 14, 1990.
Amended Answer, Affirmative Defenses, and Counterclaim of Defendant Precision Solar Controls Inc, Case No. 98-72360 dated Jul. 6, 1999.
Analog/Interace ICS, Device Data, vol. 1, Rev. 6, by Motorola, pp. 3-612-3-635.
Answer, Affirmative Defenses, and Counterclaim of Defendant Precision Solar Controls Inc dated Nov. 2, 1998.
Appeals From the United States District Court for the Eastern District of Michigan in Case No. 98-CV-72360, Judge John Feikens dated Jan. 27, 2000.
Brief for Defendants-Cross-Appellants Lumileds Lighting BV, Phillips Lighting BV, and Hewlett Packard Company, dated May 1, 2000.
Compaint, Case No. 98-72360, filed Jun. 9, 1998.
Conducted Inteference Voltage of AC-DC Converters, pp. 203-210.
Conducted Interference voltage of AC-DC Converters, By M. Albach pp. 203-212.
Conducted Interference Voltage of AC-DC Converters, by M. Albach pp. E11446-E11455.
Defendant Dialight Corporation's Answer, Affirmative Defenses, and Counterclaims, dated Nov. 2, 1998.
Defendant Ecoulux's Answer to Plaintiff's First Amended Complaint, Affirmative Defenses and Counterclaim, Case No. 98-72360.
Defendant Hewlett-Packard Company's Answer to Plaintiff's First Amended Complaint, Affirmative Defenses and Counterclaim 98-723, dated Nov. 2, 1998.
Defendant Lumileds Lighting VB's Answer to Plaintiff's First Amended Complaint, Affirmative Defenses and Counterclaims, Case No. 98-723, dated Nov. 2, 1998.
Defendant Philips Lighting BV'S Answer to Plaintiff's First Amended Complaint, Affirmative Defenses and Counterclaim, dated Nov. 2, 1998.
Defendant, Ecoulux, Inc.'s Answers to Plaintiff's Interrogatories No. 1-12, dated Feb. 1, 1999.
Design of Power Corrector for the Off-Line Isolated Buck/Boost Converter by a Voltage-Follower Techique, p. 959-964.
Design of Power Factor Corrector for the Off-Line Isolated Buck/Boost Converter by a Voltage-Follower Technique Power Factor Correction With the UC3854, by Unitrode Integrate Circuites pp. E11543-E11548.
Design of Power Factor Corrector for the Off-Line Isolated Buck/Boost Converter by a Voltage-Follower Technique, pp. 959-964.
Design Trade-Offs in Continuous Current-Mode Controlled Boost Power-Factor Correction Circuits, by Chen Zhou et al., pp. E11482-E11492.
Digitable Ubertragung Mit Lichtwellenleitern, Elekronik 14/1991, pp. 66-68.
Digital Displays, By R. Stephen, pp. 29 and 31.
Digital Feedback Light-Emitting Diode Control, by IBM Technical Disclosure Bulletin, vol. 16, No. 8 Jan. 1974, pp. 2598-2601.
Digital Feedback Light-Emitting Diode Control, By IBM, Technical Disclosure Bulletin, vol. 16, No. 8, Jan. 1974, pp. E12064-E12067.
Enhanced High Power Factor Preregulator, by Unitrode Integrated Circuits, Dated May 1993, pp. 5-226-5-229.
Enhanced High Power Factor Preregulator, by Unitrode Integrated Circuits, pp. 6-295-6300.
Enhanced High Power Factor Preregulator, dated Jan. 1995, pp. 6-295 thru 6-300.
Enhanced High Power Factor Prereulator, by Unitrode Integrated Circuits Dated May 1993, pp. 5-226 thru 5-228.
Exhibits in Support of Relume's Opposition to the Motion for Summary Judgment of Invalidity for Obviousness of Lumileds Lighting BV, Philips Lighting VB and the Hewlett-Packard Company, Case No. 98-72360.
File History for U.S. Patent: Vila-Masot et al., Patent No. 5,146,398 Issued: Sep. 8, 1992.
First Amended Complaint, Case No. 98-72360, filed Jul. 29, 1998.
Flyback Power Factor Controller, by Micro Linear, dated May 1997, pp. 8-43 thru 8-53.
High Frequency Power Conversion 1993 Conference by Harris Semiconductor, pp. E11523-E11533.
High Performance Power Factor Preregulator, By Unitrode Integrated Circuits, dated Nov. 1994, pp. 6-301 thru 6-306.
High Performance Power Factor Preregulator, dated Nov. 1994 pp. 6-301-6,-306.
High Power Factor Preregulator dated Oct. 1994 by Unitrode Integrated Circuits, pp. 6-287 thru 6-294.
High Power Factor Preregulator, by Unitrode Integrated Circuits, Dated Feb. 1993 pp. 5-218-5-225.
High Power Factor Preregulator, by Unitrode Integrated Circuits, dated Oct. 1994, pp. 6-287-6-294.
High Power Factor Preretulator, by Unitrode Integrated Circuits, dated Feb. 1993 pp. 5-218 thru5-225.
High Power Factor Switching Regulator With no Rush Current by Isao Takahashi and Ricardo Y. Igarashi, pp. E11427 and E11434.
High Power-Factor Preregulator, pp. E11477-E11481.
Improved Current Mode PWM Control, by Unitrode Integrated Circuits, dated Dec. 1992, pp. 5-229 thru 5-236.
Improved Current Mode PWM Controller, by Unitrode Integrated Circuits, Dated Dec. 1992, pp. 5-229-5-236.
Improved Current mode PWM Controller, dated Nov. 1994, pp. 6-307 thru 6-314.
Improved Current Mode PWM Controller, dated Nov. 1994, pp. 6-307-6-314.
Journal of Tsinghua University (Sci & Tech), dated 1997, pp. 89-92.
LED Driver and Pin Diode Receiver ICS for Digital Fiber Optic Communications, SPIE vol. 150 Laser & Fiber Optics Communications (1978) pp. 169-174.
LED Driver Output Level Control via Reflected Light Signal Sensing By IBM, Technical Disclosure Bulletin, vol. 23 No. 6, Nov. 1980., pp. 2187-2188.
Lovell, B., et al., Lecture 12: 9E103 Electrical Physics and Electronics, University of Queensland, Nov. 5, 2000, http://www.itee.uq.edu.au/-engg1030/lectures/1perpage/lect12.pdf#search=%22lecture%2012%20transistor%22, last visited Oct. 12, 2006.
Memorandum of Law in Support of Lumileds Lighting BV, Philips Lighting BV, and the Hewlett-Packard Company's Motion for Summary Judgment of Invalidity for Obviousness, dated Apr. 6, 1999.
Methods of Temperature Stabilization of Light-Emitting Diode Radiation, Rev. Sci. Instrum. 65 (4), Apr. 1994, American Institute of Physics pp. 803-806.
Modeling and Simulation of a Digitally Controlled Active Rectifier for Power Conditioning, by Ray Hudson pp. E11470-E11476.
Motorola Semiconductor Technical Data, Power Factor Controllers pp. #11456-E11469.
Notice of Hearing, Case No. 98-72360, dated Feb. 4, 1999.
Objections and Responses of Lumileds Lighting BV, Philips Lighting BV, and Hewlett-Packard Company to Relume's Interrogatories Nos. 1-13, dated Feb. 2, 1999.
Original Declaration of Robert B. Erickson, pp. 1-9 dated Nov. 17, 1998.
Power Factor Controller, By Electronics World, Wireless World, date: Dec. 1993 pp. 1034-1035.
Power Factor Controllers, by Motorola, pp. 3-439-3-551.
Power Factor Correction With the UC3854, by Unitrode Integrated Circuites pp. E11512-E11522.
Power Factor Correction With the UC3854, by Unitrode Integrated Circuits, pp. 1-10.
Power Supply Cookbook, by Motorola, pp. 195-200.
Practical Switching Power Supply Design, By Marty Brown pp. E11407-E11426.
Precision Solar Controls Inc.'s Answers and Objections to Relume's Interrogatories to Defendants Nos. 1-12, dated Feb. 1, 1999.
Product & Application Handbook 1993-94 by Unitrode Integrated Circuits pp. 5-213 thru 5-217.
Product & Applications Handbook 1993-1994, by Unitrode Integrated Circuits, Dated Dec. 1992, pp. 5-213-5-217.
Product & Applications Handbook 1995-1996, by Unitrode Integrated Circuits Dated Oct. 1994, pp. 6-278 thru 6-286.
Product & Applications Handbook, 1995-96, by Unitrode Integrated Circuits.
PWM Controller Chip Fixes Power Factor, By Information Access Company, Date Jun. 8, 1989, pp. 2-4.
PWM Controller Chip Fixes Power Factor; Includes Related Articles on the ML4812 Power Factor Controller and on Reasons to Correct the Power Factor, by Information Access Company, dated Jun 8, 1989, pp. 1194011954.
Relume's Opposition to the Motion for Summary Judgment of Invalidity for Obviousness of Lumileds Lighting BV, Philips Lighting BV, Philips Lighting BV and the Hewlett-Packard Company, dated Apr. 26, 1999.
Reply Brief in Support of Lumileds Lighting BV, Philips Ligthing BV, and the Hewlett-Packard Company's Motion for Summary Judgment of Invalidity for Obviousness, dated May 10, 1999.
Responses and Objections of Defendant Dialight Corporation to Plaintiff Relume Corporation's First Set of Interrogatories, dated Feb. 5, 1999.
Second Declaration of Dr. Robert W. Erickson, Ph.D., Case No. 98-72360 dated Feb. 4, 1999.
Single-Chip Controller Provides Power Factor Correction for 350W Supply, by Fernando Martin et al., pp. E11493-E11501.
Solid State Optical Designs Set the Encoder Pace, from Control Engineering May 1975 issue. pp. 40-43.
Special Masters Report, pp. 1-34 dated Jan. 10, 2002.
Supplemental Responses and Objections of Defendant Dialight Corporation to Plaintiff Relume Corporation 's First and Second Sets of Interrogatories dated ?31, 1999.
Supplemental Responses of Defendant Precision Solar Controls Inc. to Relume's Firs and Second Sets of Interrogatories dated Jun. 25, 1999 and 11, dated Apr. 30, 1999.
Supplemental Responses of Lumileds Lighting BV, Philips Lighting BV, and Hewlett-Packard Company to Relume's Interrogatories Nos. 1-7, 9 and 11, dated Apr. 30, 1999.
Supplemental Third Declaration of Dr. Robert B. Erickson, Ph.D. with Exhibit Tabs 25-34, dated May 9, 1999.
Switched Mode Power Supplies, By H.W. Whittington et al., pp. E11551-E11564.
Table Comparison of the Third and Supplemental Third Declarations of Erickson with the Lumiled's Memoranda, pp. 1-20.
The UC3823A, B & US3825A, B Enhanced Generation of PWM Controllers By Unitrode Integrated Circuits, pp. E11502-E11511.
Third Declaration of Dr. Robert B. Erickson, Ph.D. with Exhibit Tabs 1-15 dated Apr. 5, 1999.
Tri-Color LED Drive System, By IBM, Technical Disclosure Bulletin, vol. 29, No. 1 Jun. 1986, pp. 320-321.
United States District Court Eastern District of Michigan Southern Division, Case No. 98-CV-72360, Opinion and Order dated Aug. 26, 1999.

Cited By (60)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8870412B1 (en) 2000-02-11 2014-10-28 Ilumisys, Inc. Light tube and power supply circuit
US9803806B2 (en) 2000-02-11 2017-10-31 Ilumisys, Inc. Light tube and power supply circuit
US9777893B2 (en) 2000-02-11 2017-10-03 Ilumisys, Inc. Light tube and power supply circuit
US9759392B2 (en) 2000-02-11 2017-09-12 Ilumisys, Inc. Light tube and power supply circuit
US9752736B2 (en) 2000-02-11 2017-09-05 Ilumisys, Inc. Light tube and power supply circuit
US9006993B1 (en) 2000-02-11 2015-04-14 Ilumisys, Inc. Light tube and power supply circuit
US9746139B2 (en) 2000-02-11 2017-08-29 Ilumisys, Inc. Light tube and power supply circuit
US8866396B2 (en) 2000-02-11 2014-10-21 Ilumisys, Inc. Light tube and power supply circuit
US9739428B1 (en) 2000-02-11 2017-08-22 Ilumisys, Inc. Light tube and power supply circuit
US9416923B1 (en) 2000-02-11 2016-08-16 Ilumisys, Inc. Light tube and power supply circuit
US9970601B2 (en) 2000-02-11 2018-05-15 Ilumisys, Inc. Light tube and power supply circuit
US9222626B1 (en) 2000-02-11 2015-12-29 Ilumisys, Inc. Light tube and power supply circuit
US9006990B1 (en) 2000-02-11 2015-04-14 Ilumisys, Inc. Light tube and power supply circuit
US8159155B2 (en) * 2007-07-23 2012-04-17 Koninklijke Philips Electronics N.V. Light emitting unit arrangement and control system and method thereof
US20100194293A1 (en) * 2007-07-23 2010-08-05 Koninklijke Philips Electronics N.V. Light emitting unit arrangement and control system and method thereof
US8928025B2 (en) 2007-12-20 2015-01-06 Ilumisys, Inc. LED lighting apparatus with swivel connection
US8807785B2 (en) 2008-05-23 2014-08-19 Ilumisys, Inc. Electric shock resistant L.E.D. based light
US9635727B2 (en) 2008-10-24 2017-04-25 Ilumisys, Inc. Light and light sensor
US9398661B2 (en) 2008-10-24 2016-07-19 Ilumisys, Inc. Light and light sensor
US8901823B2 (en) 2008-10-24 2014-12-02 Ilumisys, Inc. Light and light sensor
US8946996B2 (en) 2008-10-24 2015-02-03 Ilumisys, Inc. Light and light sensor
US9353939B2 (en) 2008-10-24 2016-05-31 iLumisys, Inc Lighting including integral communication apparatus
US9101026B2 (en) 2008-10-24 2015-08-04 Ilumisys, Inc. Integration of LED lighting with building controls
US9585216B2 (en) 2008-10-24 2017-02-28 Ilumisys, Inc. Integration of LED lighting with building controls
US8134304B2 (en) * 2009-07-24 2012-03-13 Novatek Microelectronics Corp. Light source driving device capable of dynamically keeping constant current sink and related method
US20110018450A1 (en) * 2009-07-24 2011-01-27 Kuo-Ching Hsu Light Source Driving Device Capable of Dynamically Keeping Constant Current Sink and Related Method
US8154223B2 (en) * 2009-09-16 2012-04-10 Novatek Microelectronics Corp. Driving apparatus of light emitting diode and driving method thereof
US8288969B2 (en) * 2009-09-16 2012-10-16 Novatek Microelectronics Corp. Driving apparatus of light emitting diode and driving method thereof
US8427081B2 (en) * 2009-09-16 2013-04-23 Novatek Microelectronics Corp. Driving apparatus of light emitting diode and driving method thereof
US20120286677A1 (en) * 2009-09-16 2012-11-15 Novatek Microelectronics Corp. Driving apparatus of light emitting diode and driving method thereof
US20110062887A1 (en) * 2009-09-16 2011-03-17 Novatek Microelectronics Corp. Driving apparatus of light emitting diode and driving method thereof
USRE46330E1 (en) * 2009-09-16 2017-02-28 Novatek Microelectronics Corp. Driving apparatus of light emitting diode and driving method thereof
US20120139434A1 (en) * 2009-09-16 2012-06-07 Novatek Microelectronics Corp. Driving apparatus of light emitting diode and driving method thereof
US9013119B2 (en) 2010-03-26 2015-04-21 Ilumisys, Inc. LED light with thermoelectric generator
US9395075B2 (en) 2010-03-26 2016-07-19 Ilumisys, Inc. LED bulb for incandescent bulb replacement with internal heat dissipating structures
US8840282B2 (en) 2010-03-26 2014-09-23 Ilumisys, Inc. LED bulb with internal heat dissipating structures
US8596813B2 (en) 2010-07-12 2013-12-03 Ilumisys, Inc. Circuit board mount for LED light tube
US8894430B2 (en) 2010-10-29 2014-11-25 Ilumisys, Inc. Mechanisms for reducing risk of shock during installation of light tube
US8523394B2 (en) 2010-10-29 2013-09-03 Ilumisys, Inc. Mechanisms for reducing risk of shock during installation of light tube
US8870415B2 (en) 2010-12-09 2014-10-28 Ilumisys, Inc. LED fluorescent tube replacement light with reduced shock hazard
US9072171B2 (en) 2011-08-24 2015-06-30 Ilumisys, Inc. Circuit board mount for LED light
RU2624429C2 (en) * 2012-03-02 2017-07-03 Филипс Лайтинг Холдинг Б.В. Led lighting device and control method of led lighting device
US9184518B2 (en) 2012-03-02 2015-11-10 Ilumisys, Inc. Electrical connector header for an LED-based light
US20150219700A1 (en) * 2012-05-11 2015-08-06 Osaka City University Power factor measurement device
US9163794B2 (en) 2012-07-06 2015-10-20 Ilumisys, Inc. Power supply assembly for LED-based light tube
US9807842B2 (en) 2012-07-09 2017-10-31 Ilumisys, Inc. System and method for controlling operation of an LED-based light
US9271367B2 (en) 2012-07-09 2016-02-23 Ilumisys, Inc. System and method for controlling operation of an LED-based light
US9285084B2 (en) 2013-03-14 2016-03-15 Ilumisys, Inc. Diffusers for LED-based lights
US9267650B2 (en) 2013-10-09 2016-02-23 Ilumisys, Inc. Lens for an LED-based light
US9574717B2 (en) 2014-01-22 2017-02-21 Ilumisys, Inc. LED-based light with addressed LEDs
US9510400B2 (en) 2014-05-13 2016-11-29 Ilumisys, Inc. User input systems for an LED-based light
US20160043652A1 (en) * 2014-05-28 2016-02-11 Smart Fos, Inc. Systems and Methods for a Transformerless Power Supply to Limit Heat Generation at an Output Transistor Via Time Varying Current Draws
US9413263B2 (en) * 2014-05-28 2016-08-09 Stack Labs Inc. Systems and methods for a transformerless power supply to limit heat generation at an output transistor via time varying current draws
US9680393B1 (en) 2014-05-28 2017-06-13 Stack Labs, Inc. Systems and methods for a transformerless power supply to limit heat generation at an output transistor via time varying current draws
USD780348S1 (en) 2015-06-01 2017-02-28 Ilumisys, Inc. LED-based light tube
USD811628S1 (en) 2015-06-01 2018-02-27 Ilumisys, Inc. LED-based light tube
USD812252S1 (en) 2015-06-01 2018-03-06 Ilumisys, Inc. LED-based light tube
USD781469S1 (en) 2015-07-07 2017-03-14 Ilumisys, Inc. LED light tube
USD815763S1 (en) 2015-07-07 2018-04-17 Ilumisys, Inc. LED-based light tube
USD817523S1 (en) 2015-07-07 2018-05-08 Ilumisys, Inc. LED-based light tube

Also Published As

Publication number Publication date Type
US5661645A (en) 1997-08-26 grant
WO1997050168A1 (en) 1997-12-31 application
EP0907999A1 (en) 1999-04-14 application
EP0907999A4 (en) 1999-11-17 application
CA2259258A1 (en) 1997-12-31 application

Similar Documents

Publication Publication Date Title
US4751398A (en) Lighting system for normal and emergency operation of high intensity discharge lamps
US5767631A (en) Power supply and electronic ballast with low-cost inverter bootstrap power source
US5973455A (en) Electronic ballast with filament cut-out
US6023132A (en) Electronic ballast deriving auxilliary power from lamp output
US5859506A (en) High-efficiency incandescent lamp power controller
US20110109230A1 (en) Ballast Circuit for LED-Based Lamp Including Power Factor Correction with Protective Isolation
US8076920B1 (en) Switching power converter and control system
US20010024112A1 (en) Supply assembly for a LED lighting module
US5883473A (en) Electronic Ballast with inverter protection circuit
US6051940A (en) Safety control circuit for detecting the removal of lamps from a ballast and reducing the through-lamp leakage currents
US5604406A (en) Portable lamp for use with rapid start metal halide bulbs
US5811963A (en) Line powered DC power supply
US20020003525A1 (en) Driving circuit for LCD backlight
US5994847A (en) Electronic ballast with lamp current valley-fill power factor correction
US20020140371A1 (en) Integrated circuit for lamp heating and dimming control
US6008627A (en) Overvoltage protection circuit for a battery pack
US6469454B1 (en) Cold cathode fluorescent lamp controller
US4346331A (en) Feedback control system for applying AC power to ballasted lamps
US6049178A (en) Circuit for controlling operation of an emergency exit lamp
US6933627B2 (en) High efficiency lighting system
US20020171376A1 (en) Method for starting a discharge lamp using high energy initial pulse
US20070086128A1 (en) Equipment and methods for emergency lighting that provides brownout detection and protection
US5581161A (en) DC coupled electronic ballast with a larger DC and smaller AC signal
US6504318B1 (en) Supply coupling of a fluorescent lamp
US6304464B1 (en) Flyback as LED driver

Legal Events

Date Code Title Description
AS Assignment

Owner name: RELUME CORPORATION, MICHIGAN

Free format text: NUNC PRO TUNC ASSIGNMENT;ASSIGNOR:TRUSTEES OF THE RELUME CORPORATION UNDER AGREEMENT OF TRUST DATEDJULY 15, 2009;REEL/FRAME:026421/0913

Effective date: 20110607

AS Assignment

Owner name: AGREEMENT AND DECLARATION OF TRUST DATED JUNE 1, 2

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:RELUME CORPORATION;REEL/FRAME:027709/0308

Effective date: 20120213

AS Assignment

Owner name: WELLS, III, CHARLES, TEE, MICHIGAN

Free format text: COURT ORDER;ASSIGNOR:RELUME CORPORATION TRUST;REEL/FRAME:033268/0814

Effective date: 20140509