JP2010165645A - Led lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an LED lighting system capable of achieving smooth dimming control of LED lighting equipment from the whole illumination to lighting off as well as LED illumination without changes of luminescent colors, with the use of a phase-control lighting controller incorporated in a two-wire illumination wiring widely used currently. <P>SOLUTION: A first and a second LED illumination units 20, 30 are connected in parallel with each other, and at the same time, are connected in series with an alternating-current power source 10 via a phase-control lighting controller 40. A second LED array 31 sets the number of light-emitting diodes so as a current not to flow by summation voltage of forward voltages, without a triac 41 incorporated in the phase-control lighting controller 40 in an operating state. Further, a first LED array 21 limits the number of the light-emitting diodes so as a current exceeding a holding current to flow in the triac 41 via the first LED array 21, before a voltage exceeding the summation voltage of the forward voltages of the second LED array 31 is impressed on that LED array 31. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an LED illumination system for enabling dimming of an LED illumination device with a phase control illumination controller incorporated in a conventional two-wire illumination wiring.

  For lighting of LED lighting equipment, a method is adopted in which a commercial power supply is rectified, a high-frequency power supply is generated by a switching power supply circuit, etc., and is supplied to a plurality of light emitting diodes (LEDs) connected in series as a power supply. There are many. When LED lighting equipment that employs this type of system is dimmed by a phase control illumination controller for incandescent lamps that has been widely used in the past, it lights up at the upper limit (high current side) of the dimming range, but the lower limit direction When narrowing down to the (low current side), the light-emitting diode suddenly turned off, and on the lower limit side, there was a problem that smooth dimming was not possible before the light was turned off.

  In other words, the phase control lighting controller for incandescent lamps has a built-in phase control element (triac) connected in series with the AC power supply, and the operating state is maintained only while a current exceeding the holding current flows through the triac. Dimming is possible. On the other hand, since a plurality of light emitting diodes are connected in series to the LED lighting device, current does not flow when the voltage applied to each light emitting diode is lower than the total voltage of the forward voltage. For this reason, at the moment when the current stops flowing to the LED lighting device, the holding current does not flow to the triac, the triac is turned off, and the light cannot be adjusted. This has caused a problem that smooth dimming cannot be performed on the lower limit side as described above.

  As described above, in the phase-controlled illumination controller for incandescent lamps that is a two-wire wiring, the LED lighting devices in recent years tend to use a four-wire wiring because it is difficult to smoothly dimm the LED lighting devices. It is in. That is, there is a tendency to rectify commercial power without going through LED lighting equipment, generate high-frequency power using a switching power supply circuit, etc., control it with a newly provided signal line, and dimming LED lighting equipment is there. Patent Document 1 discloses a dimming circuit in an LED lighting device having this type of 4-wire wiring.

  However, when 4-wire wiring is adopted, it is not possible to use the 2-wire wiring structure (method) that is currently widely used, and it is necessary to construct a new 4-wire wiring. For the user, a large amount of construction cost has to be borne, and this has been a major factor that has slowed the spread of LED lighting equipment.

JP 2005-174725 A

  The present invention has been made in view of the above-described circumstances, and uses a phase-controlled illumination controller incorporated in a currently widely used two-wire illumination wiring to smoothly turn on and off LED lighting equipment. An object of the present invention is to provide an LED lighting system that can realize dimming.

In order to achieve the above object, an LED lighting system of the present invention includes a first LED array in which a plurality of light emitting diodes are connected in series, and an AC power supply full-wave rectified and output to the first LED array. A first LED lighting unit comprising: a full-wave rectifier circuit; and current limiting means for limiting a current flowing through the first LED array;
A second LED array in which a plurality of light emitting diodes are connected in series, a full-wave rectifier circuit that full-wave rectifies an AC power supply and outputs it to the second LED array, and a current flowing through the second LED array is limited. A second LED lighting unit comprising: a current limiting means to:
These first and second LED lighting units are connected in parallel to each other and connected in series to an AC power source via a phase-controlled lighting controller.
The phase control type lighting controller has a built-in phase control element that can be operated and dimmed only while a certain holding current flows.
The second LED array sets the number of light emitting diodes so that no current flows due to the total voltage of the forward voltage when the phase control element is in an off state,
The first LED array passes a holding current to the phase control element via the first LED array before a voltage exceeding the total forward voltage of the LED array is applied to the second LED array. The number of light emitting diodes is limited so that a current exceeding it flows.

  With this configuration, when a voltage exceeding the total forward voltage is applied to the second LED array, the current that has already flowed to the phase control element via the first LED illumination unit is phase-controlled. Since it is maintained above the holding current required for maintaining the operating state of the element, at least the second LED lighting unit must realize smooth dimming from full lighting to extinguishing by the phase control type lighting controller. Can do.

  Here, the phase control type lighting controller uses, for example, a triac connected in series with an AC power source as a phase control element, and a noise suppression capacitor connected in parallel to the triac. can do. The phase control illumination controller having such a configuration has been widely used as a two-wire incandescent lamp phase control illumination controller.

  Moreover, this invention can be set as the structure provided with two or more 2nd LED lighting units, and each 2nd LED lighting unit is connected in series while being mutually connected in parallel.

  According to the present invention, using a phase control type illumination controller incorporated in a two-wire illumination wiring that is currently widely used, smooth dimming from full lighting to extinguishing of LED lighting equipment and emission color does not change. An LED lighting system can be realized.

It is a circuit diagram which shows the whole structure of the LED lighting system which concerns on embodiment of this invention. It is a circuit diagram which takes out and shows the 1st LED lighting unit. It is a circuit diagram which takes out and shows a 2nd LED illumination unit. It is a wiring diagram when constructing | assembling a downlight with the LED lighting system which concerns on embodiment of this invention. (A) is a front view which shows the structural example of a downlight, (b) is a bottom view similarly. FIG. 6 is a waveform diagram showing the magnitude of voltage and current between terminals A and B in FIG. 1, where (a) is a voltage waveform at the lowest illuminance, (b) is a current waveform at the lowest illuminance, and (c) is a waveform. Voltage waveform at 90 ° dimming (intermediate illuminance), (d) current waveform at 90 ° dimming (intermediate illuminance), (e) voltage waveform at maximum illuminance, and (f) current waveform at maximum illuminance. Show. It is a figure which shows the application example of the LED lighting system which concerns on the Example of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a circuit diagram showing the overall configuration of an LED illumination system according to an embodiment of the present invention.
As shown in the figure, the LED lighting system of the present embodiment includes an AC power supply 10, a first LED lighting unit 20, a second LED lighting unit 30, and a phase control type lighting controller 40 as main components. It is out.

  The first and second LED lighting units 20 and 30 are connected in series to the AC power supply 10, respectively, and the LED lighting units 20 and 30 are connected in parallel. A plurality of second LED lighting units 30 may be provided. In this case, each second LED lighting unit 30 is connected in series to the AC power source 10 and the LED lighting units 20 and 30 are connected in parallel. Connect.

FIG. 2 is a circuit diagram showing the first LED illumination unit taken out.
The first LED illumination unit 20 includes a first LED array 21 formed by connecting a plurality of light emitting diodes in series, and a full-wave rectifier circuit that performs full-wave rectification on the AC power supply 10 and outputs the full-wave rectification to the first LED array 21. 22 and a constant current circuit 23 as current limiting means for limiting the current flowing through the first LED array 21.

In the present embodiment, a diode bridge circuit is applied to the full-wave rectifier circuit 22 and has a function of full-wave rectifying the input AC power supply 10 (commercial power supply). The full-wave rectifier circuit 22 receives power from the AC input terminal A and the terminal B of the bridge circuit shown in FIG. 2, and outputs full-wave rectified power from the DC output terminal of the bridge circuit.
The first LED array 21 is connected in series to the DC output terminal of the bridge circuit that constitutes the full-wave rectifier circuit 22.
The constant current circuit 23 is inserted in series between the first LED array 21 and the full-wave rectifier circuit 22, and an internal circuit that operates to flow a predetermined amount of current is formed.

FIG. 3 is a circuit diagram showing the second LED illumination unit taken out.
Similarly to the first LED lighting unit 20, the second LED lighting unit 30 also performs full-wave rectification on the second LED array 31 formed by connecting a plurality of light emitting diodes in series and the AC power supply 10, and is second. The full-wave rectifier circuit 32 that outputs to the LED array 31 and the full-wave rectifier circuit 33 as current limiting means for limiting the current flowing through the second LED array 31 are included. The configuration of the full-wave rectifier circuit 32 and the constant current circuit 33 and the connection between the element circuits are the same as those of the first LED lighting unit 20.

Returning to FIG. 1, the phase control type illumination controller 40 uses what is widely used for dimming an incandescent lamp called a lycon. According to this phase control type illumination controller 40, the phase angle of the power supply voltage can be arbitrarily set by operating a dimming operation knob (not shown) provided in the phase control circuit. The triac 41 (phase control element) is operated at the set phase angle of the power supply voltage to perform dimming control. The triac 41 is inserted in series with the power supply line, and is turned on when a trigger signal is input to the gate 41a, and operates while maintaining the on state as long as a constant holding current flows. On the other hand, when the holding current disappears, it is turned off to stop the operation.
The phase control type illumination controller 40 is provided with a capacitor 42 in parallel with the triac 41 as a filter for suppressing harmonic noise (radio noise) and the like.

  In the present embodiment, the number of light emitting diodes constituting the second LED array 31 is set such that no current flows due to the total voltage of the forward voltage when the triac 41 is in the off state. Further, the number of the first LED arrays 21 is passed through the first LED array 21 before a voltage exceeding the total voltage of the forward voltage of the LED array 31 is applied to the second LED array 31. Thus, the number is limited so that a current exceeding the holding current flows through the triac 41.

  That is, in the state where the operation knob for dimming of the phase control type illumination controller 40 is narrowed down and the peak value (PP) of the power supply voltage is suppressed, at least the second LED array 31 does not flow current. The number of light emitting diodes is set in advance. On the other hand, for the first LED array 21, the number of light emitting diodes is reduced so that the total voltage of the forward voltage is already lower than the peak value (PP) of the power supply voltage in this state, and current flows. A state is formed. In this case, in the circuit configuration of FIG. 1, since the capacitor 42 is provided in parallel with the triac 41 in the phase-controlled illumination controller 40, even if the triac 41 is in the off state, a current flows through the capacitor 42, and the first The LED array 21 is lit thinly.

  Next, when the operation knob for dimming is operated to increase the peak value (PP) of the power supply voltage, the current flowing through the first LED array 21 increases, and the current exceeds the holding current of the triac 41. Flows into the power line, the triac 41 is turned on to maintain the operating state. In the second LED array 31, the number of light emitting diodes is increased so that no current flows until the triac 41 is activated. Therefore, the second LED array 31 remains off until the triac 41 is activated.

  Thereafter, the dimming operation knob is further operated to increase the peak value (PP) of the power supply voltage, and when the total voltage of the forward voltages of the second LED array 31 is exceeded, the second LED array A current also flows through 31 and the light emitting diode is turned on. At this time, since the triac 41 has already been turned on and is in an operating state, at least the second LED array 31 is not suddenly lit brightly, but can be lit from a low illuminance to enable smooth dimming. .

FIG. 4 is a wiring diagram when a downlight is constructed by the LED illumination system according to the present embodiment, FIG. 5A is a front view showing a structural example of the downlight, and FIG. 4B is a bottom view thereof.
As shown in FIG. 4, a plurality of downlights 1 and 2 are connected in series to the power supply line 3, and a connection state is established in which the downlights 1 and 2 are in parallel. The phase control type illumination controller 40 is inserted in series between the AC power supply 10 and the downlights 1 and 2.
At least one of the plurality of downlights 1 and 2 is configured by the first LED lighting unit 20 illustrated in FIG. 2, and the other downlights are configured by the second LED lighting unit 30 illustrated in FIG. 3. The first LED lighting unit 20 and the second LED lighting unit 30 are different in the number of light emitting diodes constituting the LED array.
The structure of the downlights 1 and 2 can be designed arbitrarily. For example, the downlights 1 and 2 shown in FIG. 5 form an appearance with a cylindrical main body 4 whose upper surface is closed, and have a circular shape on the inner ceiling surface. The light emitting diode 5 is arranged to serve as a light source.

Next, specific examples of the present invention will be described.
The phase control method incandescent lamp dedicated dimmer (phase control type lighting controller), which is widely used at present, has an effective value of 10 to 20 V / crest value even if the dimming control knob is minimized and the illuminance is minimized. In (PP), a voltage of about 50 to 78 V is applied to the incandescent bulb.
The reason is to let you know that the dimmer is working and consuming power. For example, a phase control-type dimming lamp for incandescent bulbs is lit lightly with a current flowing even at the position where the dimming operation knob is most narrowed. The power at that time is, for example, about 8.7 W in the case of a 100 W light bulb, and about 40 W in the case of 100 W × 5 = 500 W, and power is always consumed. For this reason, generally, a cut-off switch is additionally provided in the dimmer for a phase control type incandescent lamp.

Now, in order to let you know that the dimmer is operating and consuming power, the illuminance should be minimized even when the LED lighting device is dimmed by a dimmer dedicated to a phase-controlled incandescent bulb. It is desirable that a current flows even at a position narrowed down to be lighted up.
Incidentally, in the case of an LED lighting device, for example, in the case of a 20 W type LED lighting device, about 0.2 W is always consumed at a position where the illuminance is minimized.

  LED lighting devices (especially downlights) are generally connected in parallel (around 4-5), and the current flows even at a position where the illuminance of the LED lighting device is minimized, and the LED lighting device is lit lightly. For example, in the case of a 20W type LED lighting device, about 0.2W is always consumed at a position where the illuminance is reduced to the minimum, so five LED lighting devices are connected in parallel. If it is, 0.2W × 5 = 1W always consumes power.

  On the other hand, when a plurality of (for example, five) LED lighting devices are connected in parallel, it is not necessary that all five of the LED lighting devices light up lightly, only at least one LED lighting device lights up lightly, and other LEDs Even if the lighting device is turned off, it can be confirmed that the dimmer is in operation, and doing so saves energy for four LED lighting devices.

To turn one LED lighting device out of multiple LED lighting devices connected in parallel and turn off the other LED lighting devices, limit the number of LEDs connected in series for the LED array of the LED lighting device to be turned on. On the other hand, what is necessary is just to increase the serial connection number of a light emitting diode about the LED array of another LED lighting apparatus.
Thus, by changing the number of series connection of the light emitting diodes constituting the LED array, the total voltage of the forward voltage (VF) of each LED array is different, and the forward voltage (VF) of the LED array is different. When a voltage exceeding the total voltage is applied, a current flows through the LED array and lighting is started.

Hereinafter, a specific example in which the LED lighting device to be turned on lightly is configured by the first LED lighting unit 20 described above, and the other LED lighting device to be turned off is configured by the second LED lighting unit 30 described above. This will be described with reference to FIGS.
FIG. 6 is a waveform diagram showing the magnitude of voltage and current between terminals A and B in FIG. 1, where (a) is a voltage waveform at the lowest illuminance, (b) is a current waveform at the lowest illuminance, and (c) is a waveform. Voltage waveform at 90 ° dimming (intermediate illuminance), (d) current waveform at 90 ° dimming (intermediate illuminance), (e) voltage waveform at maximum illuminance, and (f) current waveform at maximum illuminance. Show.

  For example, when the forward voltage (VF) of one white light emitting diode is 3.5 V, when the number of series connection of the light emitting diodes constituting the LED array 21 of the first LED lighting unit 20 is 20, The total voltage of the forward voltage (VF) of the LED illumination unit 20 is 3.5V × 20 pieces = 70V. On the other hand, if the number of light emitting diodes constituting the LED array 31 of the second LED lighting unit 30 is 24 in series, the total voltage of the forward voltage (VF) of the second LED lighting unit 30 is 3.5V. X24 pieces = 84V.

When the applied voltage exceeds 70V, the first LED lighting unit 20 starts to flow through the LED array 21 and starts to light. On the other hand, the total voltage of the forward voltage (VF) of the second LED lighting unit 30 is 84V, so it remains off.
When the applied voltage exceeds 84V, current begins to flow through the LED array 31 of the second LED lighting unit 30 and both the first LED lighting unit 20 and the second LED lighting unit 30 are lit. .

  For example, a phase control type incandescent lamp dedicated dimmer (phase control type illumination controller 40) currently on the market has a peak value (PP) even when the dimming operation knob is minimized and the illuminance is minimized. A voltage of about 50V to 78V is applied to the incandescent bulb. This is a case where an incandescent bulb of about 100 W is dimmed, and in the case of the first LED lighting unit 20, it is about 10 W. And since the total voltage of the forward voltage (VF) of the 1st LED lighting unit 20 is 3.5Vx20 pieces = 70V, when the peak value (P-P) exceeded 70V, the first voltage A current of about 20 mA flows through one LED array 21, and the gate 41a of the triac 41 built in the phase control type illumination controller 40 is triggered. However, since it does not satisfy the holding current (50 mA or more) of the triac 41, the triac 41 is turned on only during the trigger pulse width, but cannot keep the on state.

  However, it is divided by the total voltage of the forward voltage (VF) of the first LED array 21 and the capacitor 42 provided as a filter for suppressing high frequency noise (radio noise) inside the phase control type illumination controller 40. The applied voltage is applied to the first LED array 21. Therefore, a weak current flows through the first LED array 21, and the first LED array 21 is lit lightly. The voltage applied at this time is 70V (see FIGS. 6A and 6B), and does not exceed the total voltage (84V) of the forward voltage (VF) of the second LED lighting unit 30. The second LED lighting unit 30 remains off.

  In this way, when the triac 41 is off, a weak current flows through the first LED array 21 via the capacitor 42 inside the phase-controlled illumination controller 40, and the first LED array 21 is lit weakly. This is not preferable, but on the other hand, the LED lighting system has the following advantages. That is, in an LED illumination system employing a PWM (pulse width modulation) method, there is an effect of suppressing flicker at the time of a short pulse (pulse when the illuminance is low) peculiar to the PWM method. Even if a weak current flows through the first LED array 21 via the capacitor 42, the capacitor 42 is a reactance (impedance varies depending on the frequency) element, so heat loss does not occur, and it can be said that there is an energy saving effect. On the other hand, when another impedance is connected in parallel to the LED lighting device and the holding current of the triac 41 is ensured, the LED lighting system that expects an energy saving effect consumes useless power with no lighting effect. become.

  Next, when the operation knob for dimming of the phase control type illumination controller 40 is rotated in the direction of increasing the illuminance, the peak value (P-P) exceeds 70V and is in front of 80V, the first LED lighting unit. A current of 50 mA or more flows through 20 LED arrays 21. As a result, the gate 41a of the triac 41 of the phase control element is triggered, and since the holding current (50 mA or more) has been exceeded, the triac 41 is held in the on state.

  Further, when the operation knob for dimming of the phase control type illumination controller 40 is turned in the direction of increasing the illuminance, the peak value (P-P) exceeds 84V, and the LED array 31 of the second LED illumination unit 30 is applied. Current flows, a pulse current flows through each of the LED arrays 21 and 31 of the first LED lighting unit 20 and the second LED lighting unit 30, and the illuminance further increases (see FIGS. 6C and 6D). .

  Subsequently, when the dimming operation knob of the phase control type illumination controller 40 is turned in the direction in which the illuminance becomes brighter and the illuminance is maximized, the LED arrays of the first LED illumination unit 20 and the second LED illumination unit 30 are arranged. An even wider pulse current flows through both 21 and 31, resulting in 100% light control (see FIGS. 6E and 6F).

  The LED lighting system of the present embodiment does not require an electrolytic capacitor because it does not employ a switching circuit or the like in the circuit configuration for generating a power source. Therefore, it is not necessary to consider heat dissipation for extending the life of the electrolytic capacitor, and there is an advantage that only heat dissipation of the LED element should be considered. By the way, there are 85 and 105 degree electrolytic capacitors, and the service life when used at that temperature is 2000 to 10000 hours, etc., over which the electrolyte injected into the electrolytic capacitor evaporates. As a result, the dry-up phenomenon occurs, the capacity of the electrolytic capacitor is lost, and the life is reached.

  On the other hand, light-emitting diodes are attracting attention as elements that have a long service life of approximately 40,000 hours and contribute to energy saving with low power consumption. The system of the present embodiment is characterized in that the circuit is simple, low-cost and long-life since the circuit configuration is not performed in combination with components such as electrolytic capacitors whose lifetime has been determined.

  In the present embodiment, the currents flowing through the LED arrays 21 and 31 of the LED lighting units 20 and 30 are PWM (pulse width modulation), so that currents of the same strength periodically flow in a short time. The illuminance is low in the state, and the illuminance is high and bright if the illuminance is flowing in the same cycle for a long time. The time that each LED array 21, 31 flows is determined by the time during which the triac 41 is kept on, but the capacitor 42 inside the phase-controlled illumination controller 40 is also used when the triac 41 is off. Thus, a weak current flows through the first LED array 21, and the LED array 21 is lighted weakly. Originally, the PWM method used in pulse width identification devices for digital signals, etc., is intended to allow current to flow intermittently. Therefore, LED arrays flow especially when the pulse width is short (time) and the illuminance is low. However, not only the time when the triac 41 is turned on but also when the triac 41 is turned off, a weak current is applied to the first LED array 21 to suppress the flickering. By adopting the PWM method that periodically flows, there is an effect of not changing the emission color.

As described above, no current flows through the second LED lighting unit 30 at the position where the dimming operation knob of the phase control type illumination controller 40 is most narrowed. For this reason, about the 2nd LED illumination unit 30, 0-100% of light control is attained with the phase control type illumination controller 40. FIG.
However, since the current flows through the LED array 21 in the first LED lighting unit 20 even at the position where the dimming operation knob of the phase control type lighting controller 40 is most narrowed, the dimming range is about 30%. Dimming of 100%.

  Thus, among the LED lighting units 20 and 30 connected in parallel, only the first LED lighting unit 20 has a narrow dimming range. For example, the first LED lighting unit 20 uses a phase control type lighting controller. If the installation location is adjusted so as to illuminate 40, the scale of the phase control type illumination controller 40 is easy to see and convenient for operation.

  In addition, since the weak current is sent through the capacitor | condenser 42 which is a reactance (impedance changes with frequency) components in the 1st LED lighting unit 20, it is a dimming range by the difference in power supply frequency (50 Hz or 60 Hz). It is undeniable that brightness changes slightly at the lower limit. As a solution, for example, as shown in FIG. 7, a jujube ball 50 of about 5 W that can assist the lighting effect only in the first LED lighting unit 20 may be connected in parallel.

1, 2: Downlight, 3: Power line, 4: Body, 5: Light emitting diode,
10: AC power supply,
20: 1st LED lighting unit, 21: 1st LED array, 22: Full wave rectifier circuit, 23: Constant current circuit,
30: Second LED lighting unit, 31: Second LED array, 32: Full wave rectifier circuit, 33: Full wave rectifier circuit,
40: Phase control type lighting controller, 41: Triac, 41a: Gate, 42: Capacitor,
50: jujube sphere

Claims (3)

A first LED array formed by connecting a plurality of light-emitting diodes in series; a full-wave rectifier circuit for full-wave rectification of an alternating current power supply to output to the first LED array; and a current flowing through the first LED array A first LED lighting unit comprising: current limiting means for limiting
A second LED array formed by connecting a plurality of light-emitting diodes in series; a full-wave rectifier circuit for full-wave rectification of an AC power supply to output to the second LED array; and a current flowing through the second LED array A second LED lighting unit comprising: a current limiting means for limiting
These first and second LED lighting units are connected in parallel to each other and connected in series to an AC power source via a phase-controlled lighting controller.
The phase control type lighting controller has a built-in phase control element that can be operated and dimmed only while a constant holding current flows.
The second LED array sets the number of light emitting diodes so that current does not flow due to the sum of forward voltages when the phase control element is not activated.
The first LED array is applied to the phase control element via the first LED array before a voltage exceeding the total forward voltage of the LED array is applied to the second LED array. An LED lighting system, wherein the number of light emitting diodes is limited so that a current exceeding a holding current flows. The phase control type lighting controller includes a triac connected in series with the AC power supply as the phase control element, and a capacitor for noise suppression is connected in parallel to the triac. The LED lighting system of claim 1. 3. The LED according to claim 1, comprising a plurality of the second LED lighting units, wherein each second LED lighting unit is connected in parallel to each other and connected in series to an AC power source. Lighting system.

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