WO1999012399A1 - Ballast electronique - Google Patents

Ballast electronique Download PDF

Info

Publication number
WO1999012399A1
WO1999012399A1 PCT/US1997/020525 US9720525W WO9912399A1 WO 1999012399 A1 WO1999012399 A1 WO 1999012399A1 US 9720525 W US9720525 W US 9720525W WO 9912399 A1 WO9912399 A1 WO 9912399A1
Authority
WO
WIPO (PCT)
Prior art keywords
inverter
converter
load
voltage
lamp
Prior art date
Application number
PCT/US1997/020525
Other languages
English (en)
Inventor
Gerry P. Keogh
Gordon E. Bloom
Original Assignee
Sparton Corporation
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 Sparton Corporation filed Critical Sparton Corporation
Publication of WO1999012399A1 publication Critical patent/WO1999012399A1/fr

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
    • H05B41/26—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc
    • H05B41/28—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters

Definitions

  • This invention relates to an electronic ballast and more particularly, to an electronic ballast which is especially adapted to control the operation of an electrical load such as a gas discharge lamp which exhibits a non-linear impedance characteristic.
  • Electronic ballasts are widely used for controlling the operation of electrical load devices which have a non-linear impedance characteristic.
  • a well-known application of electronic ballasts is that of controlling the energizing current to a gas discharge lamp used in lighting and any other applications.
  • an electronic ballast must function to control the load current for regulation of the power supplied to the load.
  • the ballast should afford operation at high power factor and high efficiency. It should also provide for fault protection and lend itself ' to the reduction of electromagnetic interference.
  • the ballast should have the capability for adaptation to the characteristics of a specific lamp type in order to realize the optimum lamp performance and lamp life. Accordingly, it is desirable that the ballast should provide for soft- starting of the lamp minimal electrode erosion and equalization of erosion of both electrodes.
  • the ballast of this invention is useful for a wide variety of non-linear load devices but is especially adapted for use with gas discharge lamps. More particularly, the illustrative embodiment of the invention to be described herein is especially suitable for mercury vapor lamps. Such lamps are commonly used for generating ultraviolet radiation for use in water purification plants. The ballast requirements for such facilities are especially demanding in respect to efficiency, power factor, lamp life and cost.
  • a general object of this invention is to overcome certain disadvantages of the prior art and to provide an improved electronic ballast.
  • an electronic ballast which operates at high efficiency and power factor and which affords high output power in a compact design having low manufacturing cost.
  • an electronic ballast which is especially useful for controlling the operation of gas discharge lamps.
  • the ballast of this invention allows ionization of the lamp plasma to be formed at low drive current level with minimal high frequency, high voltage across the electrodes. Further, the drive current may be increased in a slow linear manner up to the preset running current value. Further, in the ballast of this invention, the drive current frequency is reduced to the lowest practical level after the start-up period without disturbing the stability of the plasma. When driving the plasma, the drive voltage frequency and phase are held to values close to those of the drive current and thereby achieves optimum light intensity per unit of input power.
  • a ballast which comprises a switchmode buck converter for supplying controllable DC current to an inverter for energizing the load.
  • the inverter is a full bridge inverter.
  • means are provided for reducing the frequency of the inverter after starting of the load.
  • Current control means are provided for maintaining the lamp current at a substantially constant value during running of the load, preferably, by adjusting the duty cycle of the converter.
  • Synchronizing means are coupled with the converter and inverter for synchronizing the frequency and phase of switching of the inverter and converter.
  • a starting circuit for the load comprising a starting transformer for coupling the inverter output with the load and the transformer is effectively disabled upon starting of the load.
  • FIGURE 1 is a block diagram of the electronic ballast of this invention
  • FIGURE 2 is a schematic diagram of a power rectifier and filter circuit useful with the invention
  • FIGURE 3 is a schematic diagram of a converter circuit for use with this invention.
  • FIGURE 3A illustrates a waveform typical of the converter circuit of Figure 3
  • FIGURE 4 is a schematic diagram of an inverter circuit for use with the ballast of this invention.
  • FIGURE 4A is a waveform typical of the circuit of Figure 4.
  • FIGURE 5 is a schematic diagram of the converter and inverter coupled together
  • FIGURE 6 is a schematic diagram of the ballast including a starting circuit
  • FIGURE 7 is a schematic of an alternative embodiment of the starting circuit for the ballast
  • FIGURE 8 is a diagram of a control circuit for the ballast; and FIGURE 9 is a timing diagram showing waveforms in the ballast circuit.
  • ballast in an electronic ballast circuit which is especially adapted for controlling the operation of an electrical load comprised of one or more gas discharge lamps. It will be understood that the ballast is useful for controlling other electrical loads which exhibit a non-linear impedance characteristic and that it may also be used for supplying power to electrical loads having a linear impedance characteristic. It will be appreciated, as the description proceeds, that the invention may be utilized in many different applications and may be realized in other embodiments.
  • the ballast of this invention comprises, in general, the DC/DC converter 10 which supplies a controllable DC current to a DC/AC inverter 12.
  • the inverter 12 supplies an alternating current to a gas discharge lamp 14 through a lamp starting circuit 16.
  • a programmable controller 18 is operatively connected with the converter 10, inverter 12 and lamp starting network 16.
  • the programmable controller includes a programmable logic section 22, a control and sequencing section 24 and a monitoring section 26.
  • An alternating power source such as the lines of the local public utility power company, supplies AC power to the converter 10 through a rectifier and filter 32. If needed, the power lines may be connected to the input of the rectifier and filter 32 through an electromagnetic interference (EMI) filter 34. Also, if needed the output of the rectifier and filter 32 may be connected through a power factor correction network 36 to the input of the converter 10.
  • the rectifier and filter 32 produces an unregulated high voltage DC potential at the input of the converter 10.
  • a power factor correction network 36 may be used. In an installation with a three phase AC power source, the power factor correction network 36 may be dispensed with by the use of full- wave rectifier circuitry.
  • Figure 2 shows a preferred circuit for the rectifier and filter 32 for use with a three phase delta power source.
  • the circuit of Figure 2 comprises a conventional three phase full-wave rectifier 38.
  • the nominal RMS line-to-line voltage is 440 volts and the nominal DC output voltage at the output terminals of the filter is on the order of 600 volts DC.
  • the AC ripple superimposed on the high voltage DC output is on the order of six times the AC line frequency and its peak-to-peak amplitude is only about five percent of the DC level. Accordingly, the filter capacitors can be very small and still maintain an acceptable AC ripple voltage. This minimizes the current/voltage phase lags and thus maximizes power factor.
  • the two winding filter inductor shown in Figure 2 is preferred if there is a need to obtain further reduction in the AC ripple and to increase the power factor; otherwise, the inductor may be dispensed with.
  • FIG. 3 is a schematic diagram of a switchmode converter 10' which is known as a step- down, or buck, converter. It is the same as converter 10 referred to above in Figure 1 except that converter 10, as will be described below, comprises two switches instead of one.
  • Converter 10' comprises input terminals 42 and 44 and output terminals 46 and 48.
  • the output of the filter 38 is applied to the input of the converter 10' and the output of the converter 10' is applied across a load 52.
  • the converter 10' comprises a switch 54 and an inductor 56 in series connection between the input terminal 42 and the output terminal 46. It also comprises a diode connected between the input terminal 44 and the junction of switch 54 and inductor 56.
  • the switch 54 is preferably a solid state switch.
  • the duty cycle of conduction D of the power switch 54 can be varied to control the current delivered to the load 52.
  • the load 52 is constituted by the inverter 12 and the gas discharge lamp 14.
  • the voltage pulse train which appears across the diode 52 is illustrated in Figure 3A.
  • FIG 4 is a schematic diagram of the inverter 12 which is shown in block diagram in Figure 1.
  • the inverter 12, as shown in Figure 4 is coupled through an isolation transformer 64 to a load which, in the illustrative embodiment, is a gas discharge lamp 14.
  • the inverter 12 is a bridge network of conventional design, sometimes referred to as a full-bridge inverter, with a switch in each leg of the bridge.
  • the switches 66, 68, 72 and 74 are preferably solid state switches.
  • the inverter includes input terminals 76 and 78 and output terminals 82 and 84.
  • the pair of switches 68 and 72 are simultaneously switched on and off and the pair of switches 66 and 74 are simultaneously switched on and off. The two pairs are alternately switched and one pair is on while the other pair is off.
  • the switching may be controlled so that both pairs of switches are on at the same time so as to provide some overlap in the conduction times. Since the current into the inverter is controlled, conduction overlap will not pose a problem for the switches and, in fact, permits zero voltage switching (ZVS) which results in very efficient square-wave drive for the lamp.
  • ZVS zero voltage switching
  • the inverter may also be operated so that the two pairs of switches are not turned on at the same time to thereby avoid any short circuit across the input of the inverter. In this mode, herein referred to as non-overlap switching, two pairs of switches do not conduct at the same time and switching occurs at non-zero voltage.
  • each pair of switches In either non-overlap switching or overlap switching, it is preferred to operate each pair of switches so that it is on approximately fifty percent of the time and off approximately fifty percent of the time. This is referred to herein as a fifty percent conduction duty cycle.
  • non- overlap switching is implemented with approximately fifty percent conduction duty cycle.
  • each electrode of the gas discharge lamp 14 In this mode of operation with approximately fifty percent conduction duty cycle, each electrode of the gas discharge lamp 14 is subjected to the same degree of "wear" and electrodes will be at the same temperature. This promotes long life of the lamp electrodes. Assuming that the lamp zero-to-peak voltage level is relatively constant, the effective DC input voltage to the inverter will be equal to the zero-to-peak voltage magnitude if no isolating transformer is used. Otherwise, the DC input voltage to the inverter will be that which is reflected through the turns ratio of the transformer.
  • the square wave voltage across the lamp 14 is illustrated in Figure 4A.
  • FIG. 5 is a schematic diagram showing the converter 10' of Figure 3 and the inverter 12 of Figure 4 coupled together in operational relationship.
  • the circuit nodes 46' and 48' correspond with the output terminals 46 and 48 in Figure 3. These nodes also correspond with the input terminals 76 and 78 of the inverter of Figure 4.
  • the gas discharge lamp 14 is connected directly across the output terminals 82 and 84 of the inverter instead of being coupled through an isolation transformer.
  • the RMF voltage across the lamp 14 and the RMF current through the lamp are as follows: V L ⁇ DV in ,
  • FIG. 6 is a schematic diagram showing the converter 10 coupled with the inverter 12 and showing a starting circuit 92 for the gas discharge lamp 14. Additional circuit features of the ballast are also included in this schematic diagram and will be described below.
  • the converter 10 has the same circuitry as converter 10' as discussed above except that it includes two parallel switches 54a and 54b instead of the single switch 54 of converter 10'. As will be discussed below, switches 54a and 54b are operated alternately so that one switch is on while the other is off. The duty cycles of the switches is adjustable with both switches having the same duty cycle. Each switch is operated only once over a switching period of the inverter stage to minimize power losses. In order to minimize operational switching noise, the frequency of switch operation in the converter is synchronized with that of the inverter with the inverter frequency being a fraction of the converter frequency.
  • a starting circuit 92 is coupled between the output terminals
  • the starting circuit 92 comprises an autotransformer 94 having a primary winding 96 and a secondary winding 98.
  • the turns ratio of the autotransformer is selected so as to produce a voltage high enough to initiate ionization and starting of the lamp. This starting voltage is maintained during a start-up period having a predetermined time period, typically between two and five minutes dependent upon the specific characteristics of the lamp.
  • a first starting switch 102 is connected in series with the primary winding 96 and a second starting switch 104 is connected in parallel with the secondary winding 98.
  • the starting switches 102 and 104 are movable between a "lamp-start" position and "lamp-run" position.
  • the switches are shown in the "lamp-run” position with switch 102 open and switch 104 closed. This effectively removes the autotransformer from the lamp circuit.
  • switch 102 In the "lamp-start” position, switch 102 is closed and switch 104 is open and the autotransformer is operationally connected with the lamp.
  • the lamp is started in response to a start command which is initiated by the user.
  • the switches 102 and 104 are in the lamp-start position and the autotransformer applies the starting voltage across the lamp which places the lamp in a lamp starting mode.
  • a lamp-run command is generated at the end of the start-up period and the start switches 102 and 104 are switched to the lamp-run position which will place the lamp in the running mode.
  • the starting circuit 92' comprises an autotransformer 94' having a primary winding 96' and a secondary winding 98'.
  • a coupling capacitor 106 is connected in series with the primary winding and the series combination is connected across the output terminal 82 and 84 of the inverter.
  • the secondary winding 98' is connected in series with the lamp 14 across the inverter output terminals.
  • the coupling capacitor has a sufficiently low impedance at the starting mode frequency of the inverter to energize the autotransformer so that it produces the required starting voltage for the lamp.
  • the impedance of the capacitor 106 blocks the energization of the auto transformer 94' and it is effectively eliminated from the lamp circuit during the lamp running mode .
  • the circuit includes three current transformers 112, 114 and 116 for sampling the magnitudes of the currents in the converter circuit 10 and the lamp 14.
  • the current signals from these transformers are used in a feedback control circuit for maintaining the lamp current at a constant value as will be described subsequently with reference to Figure 8.
  • the circuit is provided with a set of snubber networks each of which comprises a resistor and capacitor in series connection.
  • the snubber network 122 is connected across switch 54b
  • snubber network 124 is connected across the series combination of diode 58 and current transformer 114
  • snubber network 126 is connected across switch 66
  • snubber network 128 is connected across switch 68
  • snubber network 132 is connected across a voltage-limiting diode 108. which in turn is connected across the output terminals 82 and 84 of the inverter.
  • the ballast may be shut down due to a fault such as an excessive voltage at a selected point in the circuit, as will be described subsequently.
  • a fault such as an excessive voltage at a selected point in the circuit, as will be described subsequently.
  • the inverter switches are turned off.
  • the energy stored in the output inductor 56 of the converter must be safely dissipated.
  • a diode 134 is connected between the converter output terminal 46' and the conductor 136.
  • a filter network including a small inductor 138 and a pair of capacitors 142 and 144 are provided for use as a source of instantaneous energy during operation and as a sink for energy transferred via diode 134 from inductor 56.
  • the programmable controller 18 comprises a programmable logic section 22, a control and sequencing section 24 and a monitoring section 26.
  • the programmable logic section controls the sequencing of lamp start-up, lamp warm-up and the lamp-running mode. It also controls fault protection of the ballast and the load. Additionally, the programmable logic section processes the drive and control circuits for the converter 10 and the inverter 12, as will be described below.
  • a lamp-start signal generator 11 is provided for initiating starting of the lamp 14.
  • the start signal is applied to the control and sequencing section 24.
  • a lamp power adjust signal generator 13 is provided to adjust the current level of the converter 10 to obtain a desired power input to the lamp.
  • the power adjust signal can be either a digital or analog signal.
  • the output of the power adjust signal is applied to an input of the control and sequencing section 24.
  • the DC voltage sample is taken at the input of the converter 10 and applied through a conductor 17 to the input of the monitoring section 26.
  • the monitoring section 26 provides several indicator signals, such as lamp failure, shorted output, ballast failure, over-temperature and ground fault. These monitor signals are developed on the output lines 19 from the monitoring section 26.
  • the drive signals for the converter 10 are generated by a pulse width modulator (PWM) 142 and the drive signals for the inverter 12 are generated by a PWM 144.
  • a synchronizing signal from the PWM 142 is applied through a divide-by-N circuit 146 to the synchronizing input of the PWM 144.
  • a lamp starting interval timer 148 is coupled to the divide-by-N circuit. The starting interval timer 148 generates a frequency- change signal at a preset time delay after the lamp- start signal is generated by the signal generator 11 in response to a control input, such as activation of a switch.
  • the lamp-start signal is applied from the lamp-start signal generator 11 to the input of timer 148.
  • the time delay between the lamp-start signal and the frequency-change signal is preset to a value dependent upon the starting characteristics of the specific lamp 14 being energized by the ballast.
  • the magnitude of current supplied to the lamp 14 is controlled by adjusting the duty cycle of the buck converter 10.
  • the lamp current is sensed by the current transformer 116 and the signal is applied through a full wave rectifier to one input of an error amplifier 154.
  • the other input of the amplifier 154 receives a voltage reference signal from the lamp power signal generator 13.
  • the output of the error amplifier 154 is applied to one input of a comparator 158.
  • the other input of the comparator is a dynamic resistive voltage level developed by summed rectification of the outputs of the current transformers 112 and 114.
  • comparator 158 forms the current-mode means for assuring lamp current control stability.
  • the output of comparator 158 develops a duty cycle control signal which is applied to the duty cycle input of PWM 142. Accordingly, the lamp current is maintained at a constant value for a given setting of lamp power even though there is a change of voltage from the AC power supply.
  • Over-voltage protection is provided for the ballast circuit by means of using the voltage at one or more selected points in the ballast circuit and turning off the buck converter 10 in response to voltage which exceeds a preset limit.
  • a voltage sensor comprising a voltage divider 162 is connected between the anode of diode D2 and ground. The sensed voltage from the voltage divider is applied to the shut-down input SD on the PWM 142.
  • the operation of the PWM 142 is terminated and the buck converter 10 is stopped with both switches 54a and 54b in the open position.
  • the ballast will be described with reference to the timing and waveform diagram of Figure 9.
  • the converter 10 and inverter 12 are turned on and operated under the control of the PWM 142 and the PWM 144, respectively.
  • the relative timing of the converter drive pulses Ql and Q2 is shown by the waveforms 162 and 164 of Figure 9.
  • the relative timing of the inverter drive pulses is shown by the waveforms 166 and 168.
  • the converter current pulses through switches 54a and 54b are represented by waveform 172 with alternate pulses representing the currents through switches 54a and 54b in succession. It is noted that the switches 54a and 54b have the same on-time and hence the same duty cycle.
  • the pulses of waveform 172 are trapezoidal due to the inductor 56.
  • the diode Dl is conductive during the off-time of the converter switches 54a and 54b as represented by the current pulses of waveform 174.
  • the load current is represented by the wave form 176.

Landscapes

  • Circuit Arrangements For Discharge Lamps (AREA)

Abstract

L'invention concerne un ballast conçu pour commander le fonctionnement d'une charge électrique qui comprend un convertisseur de compensation (10) à mode commutation destiné à fournir un courant continu régulable à un onduleur (12) conçu pour alimenter la charge (14). Un contrôleur programmable (18) est connecté au convertisseur (10), à l'onduleur (12) et au réseau d'amorçage (16) de la lampe.
PCT/US1997/020525 1997-08-29 1997-11-05 Ballast electronique WO1999012399A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US91956297A 1997-08-29 1997-08-29
US08/919,562 1997-08-29

Publications (1)

Publication Number Publication Date
WO1999012399A1 true WO1999012399A1 (fr) 1999-03-11

Family

ID=25442315

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1997/020525 WO1999012399A1 (fr) 1997-08-29 1997-11-05 Ballast electronique

Country Status (1)

Country Link
WO (1) WO1999012399A1 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2169662A1 (es) * 2000-05-08 2002-07-01 Sunshower Espana S L Balasto multicarga para radiacion electromagnetica con cableado simplificado.
EP1220581A2 (fr) * 2000-12-28 2002-07-03 Setech S.r.l. Dispositif d' alimentation de lampes à décharge à cathodes froides
WO2003005779A1 (fr) * 2001-07-02 2003-01-16 Koninklijke Philips Electronics N.V. Module pmw programmable de commande de regulateur
WO2003009652A1 (fr) * 2001-07-13 2003-01-30 Sunshower España, S.L. Ballast multicharge pour l'emission de rayonnements electromagnetiques a cablage simplifie
EP1740023A2 (fr) * 2005-06-30 2007-01-03 Osram-Sylvania Inc. Ballast avec en sortie une protection contre les défauts d' isolement
EP2073609A2 (fr) * 2007-12-17 2009-06-24 Robert Bosch GmbH Arrangement de circuit pour le fonctionnement d'une lampe à decharge, ballast, et procédé correspondant

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5187414A (en) * 1988-07-15 1993-02-16 North American Philips Corporation Fluorescent lamp controllers
US5367223A (en) * 1991-12-30 1994-11-22 Hewlett-Packard Company Fluoresent lamp current level controller
US5371440A (en) * 1993-12-28 1994-12-06 Philips Electronics North America Corp. High frequency miniature electronic ballast with low RFI
US5574338A (en) * 1995-06-07 1996-11-12 Nicollet Technologies Corporation Control circuit for gas discharge lamps, which has a transformer with start and run windings

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5187414A (en) * 1988-07-15 1993-02-16 North American Philips Corporation Fluorescent lamp controllers
US5367223A (en) * 1991-12-30 1994-11-22 Hewlett-Packard Company Fluoresent lamp current level controller
US5371440A (en) * 1993-12-28 1994-12-06 Philips Electronics North America Corp. High frequency miniature electronic ballast with low RFI
US5574338A (en) * 1995-06-07 1996-11-12 Nicollet Technologies Corporation Control circuit for gas discharge lamps, which has a transformer with start and run windings

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2169662A1 (es) * 2000-05-08 2002-07-01 Sunshower Espana S L Balasto multicarga para radiacion electromagnetica con cableado simplificado.
EP1220581A2 (fr) * 2000-12-28 2002-07-03 Setech S.r.l. Dispositif d' alimentation de lampes à décharge à cathodes froides
EP1220581A3 (fr) * 2000-12-28 2003-09-03 Siet S.r.l. Dispositif d' alimentation de lampes à décharge à cathodes froides
WO2003005779A1 (fr) * 2001-07-02 2003-01-16 Koninklijke Philips Electronics N.V. Module pmw programmable de commande de regulateur
US6639368B2 (en) 2001-07-02 2003-10-28 Koninklijke Philips Electronics N.V. Programmable PWM module for controlling a ballast
CN100393181C (zh) * 2001-07-02 2008-06-04 皇家菲利浦电子有限公司 用于控制镇流器的可编程pwm模块
KR100910128B1 (ko) * 2001-07-02 2009-08-03 코닌클리케 필립스 일렉트로닉스 엔.브이. 한 세트의 신호를 생성하기 위한 장치와, ｐｗｍ 신호로 전자 안정기를 구동하는 방법과, 2개의 ｐｗｍ 신호를 제어하기 위한 장치
WO2003009652A1 (fr) * 2001-07-13 2003-01-30 Sunshower España, S.L. Ballast multicharge pour l'emission de rayonnements electromagnetiques a cablage simplifie
EP1740023A2 (fr) * 2005-06-30 2007-01-03 Osram-Sylvania Inc. Ballast avec en sortie une protection contre les défauts d' isolement
EP1740023A3 (fr) * 2005-06-30 2009-07-08 Osram-Sylvania Inc. Ballast avec en sortie une protection contre les défauts d' isolement
EP2073609A2 (fr) * 2007-12-17 2009-06-24 Robert Bosch GmbH Arrangement de circuit pour le fonctionnement d'une lampe à decharge, ballast, et procédé correspondant
EP2073609A3 (fr) * 2007-12-17 2011-12-21 Robert Bosch GmbH Arrangement de circuit pour le fonctionnement d'une lampe à decharge, ballast, et procédé correspondant

Similar Documents

Publication Publication Date Title
US5381076A (en) Metal halide electronic ballast
US5363020A (en) Electronic power controller
US5694007A (en) Discharge lamp lighting system for avoiding high in-rush current
CN1820555B (zh) 高亮度放电灯的控制
AU2008261189A1 (en) Power regulator employing a sinusoidal reference
WO1989006894A1 (fr) Ballast fluorescent atenuateur de lumiere utilisant un convertisseur d'ondes sinusoidales resonant
US7084584B2 (en) Low frequency inverter fed by a high frequency AC current source
KR0137181B1 (ko) 방전램프 점등장치
US7235932B2 (en) High efficiency ballast for gas discharge lamps
KR101021073B1 (ko) 방전 램프를 동작시키는 장치 및 방법
US6919695B2 (en) Overvoltage protection for hid lamp ballast
US6172489B1 (en) Voltage control system and method
US4568857A (en) Fluorescent light controller
WO1999012399A1 (fr) Ballast electronique
US20070145905A1 (en) Driver device for a gas discharge lamp and igniter
US4167689A (en) Solid state lamp ballast
US20090251060A1 (en) Electronic ballast system with lamp interface network
JPH11262256A (ja) 電源装置及び放電灯点灯装置
US20090243558A1 (en) Electronic ballast with hold-up energy storage
RU2409013C1 (ru) Интеллектуальный электронный балласт для газоразрядных ламп высокого давления
JP2851266B2 (ja) 放電灯用電源装置
JP4151107B2 (ja) 高圧放電灯点灯装置
Lin et al. High power factor of metal halide lamp with dimming control
GB2338358A (en) High intensity discharge lamp ballast
JP2006505918A (ja) 高圧放電灯を動作させるための回路装置

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): CA

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: CA