GB2271479A - Dimmable H.F. flourescent lamp driver with regulated output - Google Patents

Dimmable H.F. flourescent lamp driver with regulated output Download PDF

Info

Publication number
GB2271479A
GB2271479A GB9221097A GB9221097A GB2271479A GB 2271479 A GB2271479 A GB 2271479A GB 9221097 A GB9221097 A GB 9221097A GB 9221097 A GB9221097 A GB 9221097A GB 2271479 A GB2271479 A GB 2271479A
Authority
GB
United Kingdom
Prior art keywords
fluorescent
driver
lamp
transformer
supply 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.)
Withdrawn
Application number
GB9221097A
Other versions
GB9221097D0 (en
Inventor
Mahendra Tailor
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.)
TRANSMICRO Ltd
Original Assignee
TRANSMICRO Ltd
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
Application filed by TRANSMICRO Ltd filed Critical TRANSMICRO Ltd
Priority to GB9221097A priority Critical patent/GB2271479A/en
Publication of GB9221097D0 publication Critical patent/GB9221097D0/en
Publication of GB2271479A publication Critical patent/GB2271479A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
    • H05B41/14—Circuit arrangements
    • H05B41/36—Controlling
    • H05B41/38—Controlling the intensity of light
    • H05B41/39—Controlling the intensity of light continuously
    • H05B41/392—Controlling the intensity of light continuously using semiconductor devices, e.g. thyristor
    • H05B41/3921—Controlling the intensity of light continuously using semiconductor devices, e.g. thyristor with possibility of light intensity variations
    • H05B41/3927—Controlling the intensity of light continuously using semiconductor devices, e.g. thyristor with possibility of light intensity variations by pulse width modulation
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS 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
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33507—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS 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
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/53—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M7/537—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters

Abstract

A switching device 4 is turned on by a RS latch 8 in response to a pulse from a high frequency oscillator 9 and the switch is turned off when a comparator 7 detects that the primary current of a transformer has reached a reference level. The intensity of lamp 3 therefore does not change until variation of the supply voltage Vin, but can be adjusted by varying the reference input to comparator 7. The circuit may be used with the supply Vin derived from mains A.C. without filtering, and the low reactance of the circuit obviates the need for power factor correction. <IMAGE>

Description

FLUORESCENT LAMP DRIVER This invention relates to a fluorescent lamp driver.
There are a number of fluorescent lamp drivers designs. These designs provide very limited range of input voltage and there are not controllable for intensity.
Fluorescent lamp drivers are, however, relatively inexpensive.
They are used in boats, caravans, hoes, cars and camping areas.
According to the present invention it provides light source which is controllable for intensity and maintains the same intensity level and power transfer to the fluorescent lamp for any input voltage within a specify supply voltage range with high efficiency.
Embodiments of the invention will noW be described with reference to the accompanying diagram in which: Fig. 1 is a block diagram of fluorescent lamp driver.
The behaviour of the fluorescent lamp driver in Fig. 1 is two fold.
First the lamp is energized (ignite) and next when the lamp is lighted.
An oscillating circuit 9 working at high frequency, initiates power pulses by setting the RS latch 8 at a fixed frequency which turns ON switching device 4 via RS latch 8. The termination of each pulse occurs when an analog of the primary inductor current of the transformer reaches a threshold Vcont 10 established by variable resistor 6. The voltage Vcont 10 controls peak inductor current. By fixing the Vcont 10 voltage respect to Vin 1 supply, the energy in the inductor is maintained at same level during change in DC input voltage Vin 1. By controlling Vcont 10 voltage the energy in the transformer is varied, this controls the intensity of the lamp. This control takes place on cycle by cycle ( at oscillator rate) bases.
FLUORESCENT L & P DRIVER The electronic switching device 4 ( any semiconductor device ) is switched ON by the output of RS latch 8 to begin the start of energy store in the primary winding of the transformer 2. When the output from the current sense circuit 5 reaches the same level as Vcont 10, the output of comparator 8 resets the RS latch 8 such that switching device 4 is forced OFF. The energy stored in the primary winding of the transformer 2 during the ON time of switching device 4 is transferred to the secondary windings of the transformer during the off state of the switch device 4. The amount of energy stored in the primary of the transformer during the ON state of switching device 4 must be sufficient in order to strike the lamp 3 ON. This energy is defined by the primary inductance of the transformer 2.The secondary windings of the transformer 2 consist of two heater windings and one main windings which provides strike voltage during start up. The strike voltage for the fluorescent lamp is higher than when the lamp is ON. Due to high impedance load on secondary of the transformer 2 when the lamp 3 is OFF ( not lighted) which in turn produces high voltage across the lamp 3, between two heater windings. This high impedance load also causes high voltage to develop across the heater windings, heating the heater in the lamp 3 which causes the lamp to strike ON. Once the lamp is ON the peak voltage (back EMF voltage) is limited across the switching device and the secondary winding due to the lamp load, which also reduces voltage across the heater winding. It is the back EMF voltage during OFF state of the switching device 4 which causes the lamp to ignite.
The design of transformer depends on the input voltage Vin 1 if the working voltage of the lamp is less than the input voltage the design will require step-down transformer. For working voltage of lamp greater than the input voltage the design will require step-up transformer. In both the cases the inductance of the primary should be such that the energy stored during ON state must be sufficient to strike the lamp ON with the back EMF.
FLUORESCIT LAMP DRIVER If the voltage supply source Vin 1 is mains derived, the lamp driver can tolerate very high rate of ripple voltage since the current in the transformer is controlled on cycle by cycle bases at very high frequency compared to the trains frequency. This reduces a need to filter the in coming mains DC supply which gives lamp driver very low reactance load to the mains supply and hence a very low effect on the power factor reduces the need to correct the power factor in the fluorescent lamp driver.
The current sense circuit is made of a resistor or a current transformer.

Claims (8)

  1. FLUORESCENT LAMP DRIVER
    CLAIMS 1. A fluorescent driver comprising of a comparator, RS latch, current sense circuit, oscillator, transformer and fluorescent lamp provide, means of striking the lamp ON, variable controlled regulated intensity with maintained power transfer over the range of supply voltage.
  2. 2. A fluorescent driver as claimed in Claim 1 wherein the back EMF strikes the lamp ON.
  3. 3. A fluorescent driver as claimed in Claim 1 wherein the intensity is controlled by varying the peak current in the primary of the transformer.
  4. 4. A fluorescent driver as claimed in Claim 2 wherein the peak current is measured by current sensing circuit in series with the primary of the transformer.
  5. 5. A fluorescent driver according to claim 4 wherein the current in the primary windings of the transformer is controlled at the oscillator rate.
  6. 6. A fluorescent driver as claimed in Claim 1 wherein the change in supply voltage will maintain the power transfer in the fluorescent lamp.
  7. 7. A fluorescent driver as claimed in Claim 1 require no power factor correction for supply voltage derived fran mains.
  8. 8. A fluorescent driver substantially as described herein with reference to Fig. 1 of the accompanying drawing.
GB9221097A 1992-10-07 1992-10-07 Dimmable H.F. flourescent lamp driver with regulated output Withdrawn GB2271479A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB9221097A GB2271479A (en) 1992-10-07 1992-10-07 Dimmable H.F. flourescent lamp driver with regulated output

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9221097A GB2271479A (en) 1992-10-07 1992-10-07 Dimmable H.F. flourescent lamp driver with regulated output

Publications (2)

Publication Number Publication Date
GB9221097D0 GB9221097D0 (en) 1992-11-18
GB2271479A true GB2271479A (en) 1994-04-13

Family

ID=10723107

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9221097A Withdrawn GB2271479A (en) 1992-10-07 1992-10-07 Dimmable H.F. flourescent lamp driver with regulated output

Country Status (1)

Country Link
GB (1) GB2271479A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2372161A (en) * 2000-10-25 2002-08-14 Raymarine Ltd Fluorescent lamp driver circuit
EP2259661A3 (en) * 2004-02-13 2011-04-06 Lutron Electronics Co., Inc. Multiple-input electronic ballast with processor

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0014833A1 (en) * 1979-01-23 1980-09-03 Siemens Aktiengesellschaft Circuit for controlling the output voltage of a switching converter
GB2151822A (en) * 1983-12-23 1985-07-24 Gen Electric Plc Dc-dc converter
GB2163309A (en) * 1984-08-17 1986-02-19 Lutron Electronics Co High frequency gas discharge lamp dimming ballast
EP0208370A1 (en) * 1985-07-06 1987-01-14 Philips Patentverwaltung GmbH Circuit arrangement for the operation of high pressure gas discharge lamps
GB2212995A (en) * 1987-10-23 1989-08-02 Rockwell International Corp Fluorescent lamp dimmer
US4879641A (en) * 1987-11-02 1989-11-07 Sgs-Thomson Microelectronics S.R.L. Analog multiplex for sensing the magnitude and sense of the current through a h-bridge stage utilizing a single sensing resistance
US4885674A (en) * 1988-03-28 1989-12-05 Varga Ljubomir D Synthesis of load-independent switch-mode power converters

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0014833A1 (en) * 1979-01-23 1980-09-03 Siemens Aktiengesellschaft Circuit for controlling the output voltage of a switching converter
GB2151822A (en) * 1983-12-23 1985-07-24 Gen Electric Plc Dc-dc converter
GB2163309A (en) * 1984-08-17 1986-02-19 Lutron Electronics Co High frequency gas discharge lamp dimming ballast
EP0208370A1 (en) * 1985-07-06 1987-01-14 Philips Patentverwaltung GmbH Circuit arrangement for the operation of high pressure gas discharge lamps
GB2212995A (en) * 1987-10-23 1989-08-02 Rockwell International Corp Fluorescent lamp dimmer
US4879641A (en) * 1987-11-02 1989-11-07 Sgs-Thomson Microelectronics S.R.L. Analog multiplex for sensing the magnitude and sense of the current through a h-bridge stage utilizing a single sensing resistance
US4885674A (en) * 1988-03-28 1989-12-05 Varga Ljubomir D Synthesis of load-independent switch-mode power converters

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2372161A (en) * 2000-10-25 2002-08-14 Raymarine Ltd Fluorescent lamp driver circuit
GB2372161B (en) * 2000-10-25 2003-03-12 Raymarine Ltd Fluorescent lamp driver circuit
US6879114B2 (en) 2000-10-25 2005-04-12 Raymarine Limited Fluorescent lamp driver circuit
EP2259661A3 (en) * 2004-02-13 2011-04-06 Lutron Electronics Co., Inc. Multiple-input electronic ballast with processor
US8111008B2 (en) 2004-02-13 2012-02-07 Lutron Electronics Co., Inc. Multiple-input electronic ballast with processor

Also Published As

Publication number Publication date
GB9221097D0 (en) 1992-11-18

Similar Documents

Publication Publication Date Title
EP0650313B1 (en) Apparatus for operating a fluorescent lamp of an image forming apparatus
US11950336B2 (en) Load control device for a light-emitting diode light source having different operating modes
EP0548342B1 (en) Fluorescent lamp ballast for pulsed-mode operation
US4005335A (en) High frequency power source for fluorescent lamps and the like
RU2292677C2 (en) Method for extracting power for auxiliary device from signal, sent to light from phase light controller
US5742132A (en) Method and system for starting and operating a discharge lamp
JP2001338793A (en) Double-control dimming ballast device
CN109315036A (en) Load control device for LED source
JPS62295398A (en) Method of operating gas discharge lamp and gas discharge controller
US5933340A (en) Frequency controller with loosely coupled transformer having a shunt with a gap and method therefor
US4484107A (en) Discharge lamp lighting device and system
US5959408A (en) Symmetry control circuit for pre-heating in electronic ballasts
JP2005510834A (en) Discharge lamp electrode heating device
WO1992003898A1 (en) System for providing a constant level current to a fluorescent tube
US5543690A (en) High voltage ignition circuit for a discharge lamp
US20110298383A1 (en) Electronic operating device for a gas discharge lamp
US4376911A (en) Circuit system for lighting a discharge lamp or lamps
JP2002511181A (en) Circuit device for dimmable operation of fluorescent lamps
US4266165A (en) High intensity discharge lamp starting circuit
US5608292A (en) Single transistor ballast with filament preheating
GB2271479A (en) Dimmable H.F. flourescent lamp driver with regulated output
JPH076884A (en) Circuit for generating signl operating dc arc dischrge lamp
EP0958715B1 (en) Ballast
EP0739154B1 (en) Supply circuit for gas discharge lamps
KR0169164B1 (en) Rapid start type fluorescent lamp starting circuit

Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)