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WO1995012300A1 - Double ballast d'attaque resonnant pour lampes a gaz - Google Patents

Double ballast d'attaque resonnant pour lampes a gaz Download PDF

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Publication number
WO1995012300A1
WO1995012300A1 PCT/US1994/012387 US9412387W WO9512300A1 WO 1995012300 A1 WO1995012300 A1 WO 1995012300A1 US 9412387 W US9412387 W US 9412387W WO 9512300 A1 WO9512300 A1 WO 9512300A1
Authority
WO
WIPO (PCT)
Prior art keywords
transformer
power supply
current
primary coil
gas
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.)
Ceased
Application number
PCT/US1994/012387
Other languages
English (en)
Inventor
David A. Christian
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.)
Marshall Electric Corp
Original Assignee
Marshall Electric 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
Application filed by Marshall Electric Corp filed Critical Marshall Electric Corp
Priority to CA002173873A priority Critical patent/CA2173873C/fr
Priority to AU81281/94A priority patent/AU8128194A/en
Publication of WO1995012300A1 publication Critical patent/WO1995012300A1/fr
Anticipated expiration legal-status Critical
Ceased 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
    • H05B41/26—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
    • H05B41/282—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 with semiconductor devices
    • H05B41/285—Arrangements for protecting lamps or circuits against abnormal operating conditions
    • H05B41/2851—Arrangements for protecting lamps or circuits against abnormal operating conditions for protecting the circuit against abnormal operating conditions
    • 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
    • H05B41/282—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 with semiconductor devices
    • H05B41/285—Arrangements for protecting lamps or circuits against abnormal operating conditions
    • H05B41/2858—Arrangements for protecting lamps or circuits against abnormal operating conditions for protecting the lamp against abnormal operating conditions

Definitions

  • the present invention relates to electronic ballast circuitry, and, more particularly, to ballast circuits for 5 driving gas-filled arc-type lamps.
  • Gas-filled arc-type lamps e.g., neon lamps, require high voltage input signals for proper operation. Such lamps are commonly driven by output transformer ballast
  • Electronic ballast circuits generally include a transformer and an oscillation device which accept an input power source and operate to alter the input power source to provide a high frequency, high voltage output having proper characteristics to drive the gas-filled arc-
  • Electronic ballast circuits utilize electronic switches in the form of transistors to satisfy the high frequency requirement, typically controlled by pulse-width modulation.
  • the transistors are connected to operate in a push/pull mode, thereby providing a high
  • __0 frequency oscillating signal.
  • High frequency operation provides the advantage of reduced power consumption by way of iirproved lighting efficiency and reduced power dissipation in the ballast.
  • ballast circuits typically derives power directly from the input transformer power source, resulting in unnecessary power consumption and heat build up.
  • Another potential problem traditionally associated with ballast circuits involves the squealing and humming caused by
  • Another need is to monitor the output for operation into impermissible loads and shut down the system operation upon the occurrence of such conditions.
  • Another need is for an inverter which substantially eliminates electronic interference, and thereby eliminates the squeal and hum associated with such gas filled lamps.
  • Another need is for an output signal that automatically disperses "bubbles" or visible standing waves when the lamp is illuminated without the need of operator adjustment.
  • the present invention provides a fullwave push/pull double parallel resonant inverter circuit for use as a gas-filled arc-type lamp driver ballast.
  • the inverter circuit provides a high voltage, high frequency, low current output signal to drive the gas filled lamp load and disperse standing wave patterns, or "bubbles".
  • the inverter is comprised of a control section which derives its power from a secondary winding opposite the in-line transformer DC power supply inductor choke which supplies a reduced level power supply to the control circuit to reduce power consumption and eliminate unnecessary temperature rises.
  • the inverter control section is comprised of an op-amp circuit which provides an input undervoltage lockout section, an excess primary overvoltage lockout, and a major output current imbalance lockout to self-protect the device against faulty operation.
  • the design includes the following functional sections: DC power source, start-up bias, control circuit power source, oscillator control circuit, output transformer section, and load side signal balancing section.
  • the DC power section accepts a standard 120 VAC, 60 Hz power source. This signal is rectified through a fullwave bridge rectifier in parallel with a filter capacitor such that a rectified filtered DC power source is supplied to the start-up bias section.
  • the start-up bias section comprises a large value resistor used to develop the start-up bias for the control circuitry.
  • the present invention includes a secondary winding opposite the series current choke inductor which provides a biased DC source of 10 V to 15 V. This biased DC control circuit power source greatly reduces temperature rise and power consumption.
  • the control circuit power source drives the op-amp devices and the switching transistors.
  • the present invention provides for the dispersion of standing waves, thereby eliminating the degradation of the lamp appearance caused by unsightly gas bubbles.
  • Standing wave dispersion is achieved by introducing an even order harmonic distortion to the primary waveform which causes an equivalent distortion on the secondary side. Due to the sensitive nature of the gas, a constant flow of ionized gas is achieved.
  • Even order harmonic distortion may be accomplished by several means, including, but not limited to, using a capacitor or inductor in parallel with the primary output transformer winding resulting in an unbalanced conductance with respect to the tap of the primary. This unbalancing of the admittance on the primary side has the effect of "moving" the bubbles along through the lamp rendering such bubbles invisible to the human eye.
  • the type or shape of the tube is determinative of the degree of harmonic distortion required to sufficiently disperse the problematic standing waves.
  • the present invention is configured to provide proper dispersion over a wide variation in lamp tube design.
  • the present invention features a quad op-amp device which provides an input undervoltage lockout, excess primary voltage lockout, and a major output current imbalance lockout.
  • the input undervoltage lockout device disables the circuit by preventing the switching transistors from switching to a conducting state and thereby prevents current flow through the inverter.
  • the excess primary voltage lockout senses the current allowed through the Zener diode voltage clamp and, upon sensing an excessive level, resets the control circuit, thereby placing the switching transistors in a non-conducting state.
  • the major output current imbalance lockout senses the input and output sides of the transformer, and shuts down the switching transistors when insufficient power is delivered to the output side.
  • One embodiment of the invention provides a resistor between the center tap of the output winding and the internal circuit ground which is monitored by an op-amp.
  • the secondary load becomes imbalanced, current flows through the resistor.
  • the voltage across the resistor rises and, upon attaining a prescribed level, the circuit sets the lockout circuit, thereby placing the switching transistors in a non-conducting state.
  • the present invention provides for enhanced voltage limited operation. If the voltage level across the primary exceeds a certain level, the series zener diode voltage clamp conducts and connects the path to circuit ground. The clamp current is monitored and an excessive level sets the control circuitry. Due to the tight coupling of the primary and secondary windings in the current fed ballast and the use of the balancing capacitors, the output voltage accurately reflects that of the primary winding. By limiting the primary side voltage, the circuit correspondingly limits the output voltage.
  • the present invention also provides reduced electrical interference. Due to the high frequency resonant nature of the device, the output lamps tend to stay at least partially ionized through both halves of each cycle. This results in less arcing noise, less arc establishment noise, less broad band static, and less radiated noise.
  • the high voltage circuitry of the present invention is encased in a dense, resilient, hydrophobic compound which exhibits superior high voltage and high frequency insulation characteristics.
  • One object of the present invention is to provide a voltage limited inverter with a performance characteristic resulting in a voltage limited output. Another objective of the invention is to provide monitoring and safety disabling capabilities in the event of impermissible loads, input undervoltage start-up lockout, and current limiting overvoltage shunting in order to reduce damage potential. Another . ject of the invention is to provide reduced temperature rise and power consumption and therefore a more efficient lighting circuit.
  • Another objective of the invention is to provide the end user with simplicity and increased safety in operation. Another object of the invention is to significantly reduce electrical interference in the form of noise and standing waveforms.
  • Figure 1 is a schematic circuit diagram of a first embodiment of the neon driver ballast circuitry
  • FIG. 2 is a schematic circuit diagram of a second embodiment of the neon driver ballast circuitry.
  • FIG. 2 is a schematic circuit diagram of a second embodiment of the neon driver ballast circuitry.
  • Corresponding reference characters indicate corresponding parts throughout the several views.
  • the exemplification set out herein illustrates preferred embodiments of the invention, in two forms, and such exemplification is not to be construed as limiting the scope of the invention in any manner.
  • FIG 1 schematically illustrates a first embodiment of gas-filled arc-type lamp, such as neon, driver ballast 20 in which tuned transformer Tl delivers a sufficient high frequency AC output across contact points W2 and W3 to excite the neon or other gas in discharge lamp 22.
  • Driver ballast 20 consists of DC power source 24 having start-up section 26, high frequency series push-pull inverter circuit 28, and transformer Tl.
  • Transformer Tl is comprised of windings PI through P4, SI and S2, and a ferrite core possessing characteristics such that the primary and secondary windings are tightly coupled resulting in a double parallel resonant circuit. This tight coupling allows for reliable sensing of the secondary load conditions at the primary winding.
  • DC power source 24 derives its power from standard 120 VAC 60 Hz power source Wl.
  • On/off switch SI energizes and de-energizes electronic ballast system 20.
  • DC power source 24 additionally consists of surge inrush current lim:ter SRI, low frequency filter capacitor Cl, over te ⁇ r,_ arature fuse FI, serpentine fuse F2, and inductors LI and L2.
  • Full wave bridge rectifier circuit 30 includes a bridge circuit formed of diodes D1-D4 and MOV1, which is connected across the AC main as a protection device to guard against voltage spikes. Rectifier circuit 30 in conjunction with capacitor C2 provides a rectified and filtered DC power source to drive inverter tra n sformer Tl.
  • Start-up section 26 includes capacitor C2, re., _-tor Rl, and diode D5. This input rectifier and filter arrangement provides DC voltage and blocks reverse conduction of high frequency noise. The resulting DC output of the full wave bridge rectifier is approximately 150 V.
  • Inductor L3 is placed in series with ⁇ C power source 24 and serves as a DC current choke to primary windings PI and P2 of transformer Tl. Rather than feed control circuitry 32 directly with DC power source 24 of approximately 150 V, secondary choke winding L4 is utilized to generate a DC bias voltage of 10 V to 15 V. Stepping down from 150 V to the range of 10 V to 15 V serves to lower the 15 to 25 watts of control bias normally required down to 3 to 4 watts thereby conserving power and reducing temperature rise. Start-up bias resistor Rl develops the start-up bias for control circuitry 32. Inductor L3 also provides a current source along path 34.
  • Inductor L3 feeds DC supply current to primary windings PI and P2, providing a high impedance, a low DC resistance, and a filtering function in conjunction with capacitor C2. Accordingly, resonant switching wave forms are not allowed into the main supply.
  • Capacitor C5 provides an unbalanced capacitance with respect to tap 36 of the primary winding, as will be discussed in detail below.
  • Control circuitry 32 is comprised primarily of op- amps U1A, U1B, U1C, and U1D which serve as an input undervoltage lockout, a set/reset flip/flop device, an unbalance current lockout, and an impermissible load lockout.
  • Undervoltage lockout op-amp U1A prevents system operation until main DC supply 24 reaches a sufficient level to drive ballast system 20. Until such time, driver U1C is in an "off" state providing no bias current to the Darlington pair Q3 and Q4. By depriving the Darlington circuit of sufficient bias current, current is not allowed to pass from collector through emitter of transistors Q3 and Q4 and consequently current is not allowed to flow through the inverter circuit.
  • Op-amp U1D acts as an impermissible load sensor and, in conjunction with current sensing resistor R20, de-energizes the control circuit in the event of insufficient delivered load power by setting the flip/flop circuit of op-amp U1B.
  • op-amp U1B By setting op-amp U1B, switching transistors Q3 and Q4 are deprived of sufficient bias current along current path 34 to drive switching transistors Q3 and Q4 to their respective conducting states.
  • switching transistors Q3 and Q4 By placing switching transistors Q3 and Q4 in their respective nonconducting states, current is not allowed to flow through collector to emitter of the switching transistors thereby precluding primary winding current flow through the current path 38.
  • Push/pull full wave oscillator 28 comprises oscillation transistors Ql and Q2.
  • Oscillation transistors Ql and Q2 act in a push/pull manner with feedback windings P3 and P4 to provide an oscillation feedback signal inversely corresponding to the voltage apparent at primary windings Pi and P2.
  • This feedback signal alternately switches power transistors Ql and Q2 to their respective conducting states, thereby alternately allowing primary winding current to pass through collector to emitter.
  • Diodes D6 and D7 rectify the voltage signal produced by primary windings PI and P2, and zener diodes D23 and D24 act as an overvoltage clamp.
  • zener diode series combination D23 and D24 If the voltage across the primary windings exceed the threshold limit of the zener diode series combination D23 and D24, then these devices will conduct and allow current to flow through to circuit ground. In series with zener diodes D23 and D24 is resistor R12. Should the current through resistor R12 exceed a predetermined voltage level, then op-amp U1B is triggered and the flip/flop circuit is set.
  • the frequency of push/pull fullwave oscillator 28 is determined by primary side capacitor C3 in parallel with the primary windings. These elements acting in parallel resonate the collectors of oscillator transistors Ql and Q2.
  • Primary windings P3 and P4 provide feedback to the bases of oscillator transistors Ql and Q2.
  • Secondary windings SI and S2 provide high voltage sine waveform to output resonating capacitors C7 and C8 and the load, lamp 22, at outputs W2 and W3.
  • Resonating capacitors C7 and C8 also act as ballasting reactances for the load, and provide blocking of direct and low frequency alternating current to the load.
  • Output windings SI and S2 are connected in series to resonating capacitors C7 and C8 and in series with the load resulting in gas discharge lamp 22 being an element in the resonant ballast circuit with the resonating capacitors C7 and C8 tuning the output frequency.
  • the preferred embodiment of the transformer calls for having primary winding PI, P2 coaxially positioned about a core, such as an E-type core.
  • the secondary winding SI, S2 should be coaxially disposed about the primary winding with both primary and secondary windings being mounted on a common core. This provides tight coupling between the primary and secondary windings and overall reduction in size. In addition, the tight coupling provides self- sheilding, resulting in virtual elimination of magnetic field radiation and associated power losses. In this manner, the output of the secondary winding will emulate the waveform associated with the primary winding and the secondary waveform may be accurately monitored from the primary side.
  • an even order harmonic distortion is introduced to the output waveform. This is achieved by causing an imbalance on the primary windings of transformer Tl.
  • This imbalance can be created by any of several different means including but not limited to: clipping, clamping, and alternating voltages.
  • capacitor C3 connected between the primary windings and common achieves the desired unbalancing. This imbalance results in distorted sine waves. One half-cycle will be slightly longer than the other with slightly lower peak voltage.
  • Secondary side load current imbalance monitoring circuit 50 includes capacitor Cll and C12, diodes D8 and D9, and resistor R21. Capacitors Cll and C12 and resistor R21 are coupled between center tap 52 of secondary windings SI and S2 and circuit ground. If the load is reasonably balanced, e.g., plus or minus 20% with respect to circuit ground, then insufficient current flows through resistor R21 to develop sufficient voltage to set op-amp U1B. In the event of a major current imbalance, resistor R21 generates sufficient voltage to set op-amp U1B. Once op-amp UIB is set, the power transistor arrangement of high frequency oscillation circuit 28 is placed in a non-conducting state thereby disallowing current flow through the primary windings.
  • the high voltage components are encased in a dense, resilient, hydrophobic compound exhibiting superior high voltage and high frequency insulation characteristics.
  • the encasing compound is polyurethane based potting compound.
  • MOV1 150VAC 7.0 j MOV2 360VDC, 7.0 j MOV3 240VDC, 7.0 j SRI 3A, SG-220 (Surge
  • the embodiment shown in Figure 2 is a schematic block diagram representation of the ballast circuit shown in Figure 1 with an alternative monitoring circuit for detecting significant current imbalances with respect to the secondary load.
  • the ballast circuit of Figure 2 includes a DC power source, control circuitry, transformer section, oscillation transistor section, and output section.
  • Ballast circuit 20' accepts AC power source 24' and rectifies the signal by full wave bridge rectifier 30'.
  • the resulting rectified and filtered DC power source is coupled to current choke inductor L3' and is supplied along current path 34' to the primary windings of ballast transformer Tl• .
  • Secondary choke inductor L4* is coupled to current choke inductor L3• and steps down the DC power source through start-up section 26' to provide a reduced power source to power control circuitry 32' at input 40.
  • Control circuit 32' monitors the DC power source via undervoltage lockout input 42 whereby ballast circuit operation is precluded upon sensing an insufficient source of power being supplied to the primary windings of ballast transformer Tl • . Where the voltage across the primary windings exceeds the threshold limit of overvoltage clamp 44', then current flows to circuit ground. Coupled to overvoltage clamp 44' is resistor R12 ' which, upon developing an excessive voltage level, may reset control circuit 32• through input 46 and interrupt ballast circuit operation. As current flows through the primary side of transformer Tl', oscillation circuit 28*, and control circuitry 32', resistor R20 1 develops a voltage signal which is introduced to control circuit 32• at input 48. Upon the occurrence of an undercurrent condition, the voltage developed across resistor R20' is sufficient to set control circuit 32' and thereby interrupt ballast circuit operation.
  • Transformer Tl' is comprised of windings PI' through P4• , SI• and S2' , and a ferrite core possessing characteristics such that the primary and secondary windings are tightly coupled resulting in a double parallel resonant circuit. This tight coupling allows for reliable sensing of the secondary load conditions on the primary side.
  • Secondary side load current imbalance monitoring circuit 50' includes DC isolation capacitor C9, diode D28, and resistor R21. Capacitor C9 and resistor R21 1 are coupled between center tap 52' of secondary windings SI and S2 and circuit ground. If the load is reasonably balanced, e.g., plus or minus 20% with respect to circuit ground, then insufficient current flows through resistor R21 to develop sufficient voltage to set control circuit 32 at input 54. In the event of a major current imbalance, resistor R21 generates sufficient voltage to set control circuit 32' at input 54. Once control circuit 32* is set, the power transistor arrangement of high frequency oscillation c_rcuit 28' is placed in a non-conducting state thereby disallowing current flow through the primary windings.
  • Feedback windings P3' and P4' provide high frequency oscillation circuit 28' with a feedback signal inversely (i.e., anti-phase) corresponding to the voltage apparent at the primary windings.
  • This feedback winding alternately switches the transistor arrangement found within oscillation circuit 28' to a conducting state, thereby allowing primary winding current to pass through oscillation circuit 28' to circuit ground.
  • the frequency of oscillation circuit 28' is determined by primary side capacitor C3• in parallel with the primary windings. These elements acting in parallel resonate the collector(s) of the oscillator transistor(s) associated with oscillation circuit 28'.
  • Windings P3• and P4• provide feedback to the base(s) of the oscillator transistor(s) associated with oscillation circuit 28'.
  • Windings SI• and S2* provide high voltage sine waveform to output resonating capacitors C7' and C8' and the load at outputs W2' and W3• .
  • Secondary windings SI 1 and S2' are connected in series to resonating capacitors C7' and C8• and in series with the load resulting in gas discharge lamp 22' being an element in the resonant ballast circuit.
  • an even order harmonic distortion is introduced to the output waveform. This is achieved by causing an imbalance at the primary coil of transformer Tl' .
  • This imbalance can be created by any of several different means including but not limited to; clipping, clamping, and alternating voltages.
  • capacitor C3' is connected between the primary coil and common to achieve the desired unbalancing. This imbalance results in distorted sine waves. One half-cycle will be slightly longer than the other, with slightly lower peak voltage. This results in a similar distortion in the current flowing through gas discharge lamp 22* .
  • the gas inside the tube is very sensitive to this distortion such that it results in a constant flow of ionized gas toward one end or the other. This dispersion of standing waves serves to inhibit the formation of bubbles within the lamp tube.

Landscapes

  • Circuit Arrangements For Discharge Lamps (AREA)

Abstract

L'invention concerne une double alimentation résonnante en parallèle (20') pour lampe à décharge (22, 22') remplie de gaz. L'élément de commande (32') remplit des fonctions de blocage en cas de tension d'entrée insuffisante, de tension primaire excessive, et de déséquilibre de la tension de sortie principale qui permettent de couper l'alimentation lorsque des conditions de fonctionnement anormales sont détectées.
PCT/US1994/012387 1993-10-28 1994-10-28 Double ballast d'attaque resonnant pour lampes a gaz Ceased WO1995012300A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CA002173873A CA2173873C (fr) 1993-10-28 1994-10-28 Double ballast d'attaque resonnant pour lampes a gaz
AU81281/94A AU8128194A (en) 1993-10-28 1994-10-28 Double resonant driver ballast for gas lamps

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US14466193A 1993-10-28 1993-10-28
US08/144,661 1993-10-28

Publications (1)

Publication Number Publication Date
WO1995012300A1 true WO1995012300A1 (fr) 1995-05-04

Family

ID=22509566

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1994/012387 Ceased WO1995012300A1 (fr) 1993-10-28 1994-10-28 Double ballast d'attaque resonnant pour lampes a gaz

Country Status (4)

Country Link
CN (1) CN1060307C (fr)
AU (1) AU8128194A (fr)
CA (1) CA2173873C (fr)
WO (1) WO1995012300A1 (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2353153A (en) * 1999-07-26 2001-02-14 Microlights Ltd Discharge lamp ballast with reduced shock hazard
WO2001037617A1 (fr) * 1999-11-17 2001-05-25 Koninklijke Philips Electronics N.V. Circuit de ballast
WO2001093643A1 (fr) * 2000-05-31 2001-12-06 Keith Billings Ballast de lampe permettant de reduire le courant d'interference
WO2001093644A3 (fr) * 2000-06-01 2002-02-28 Everbrite Inc Lampe a decharge gazeuse comprenant un circuit de protection de fuite
WO2002080288A3 (fr) * 2001-03-30 2002-12-27 Maxim Integrated Products Appareils et processus de source de courant pour diodes electroluminescentes

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7382099B2 (en) * 2004-11-12 2008-06-03 General Electric Company Striation control for current fed electronic ballast

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4916362A (en) * 1988-04-05 1990-04-10 Neon Dynamics Corporation Excitation supply for gas discharge tubes
US5103138A (en) * 1990-04-26 1992-04-07 Orenstein Edward D Switching excitation supply for gas discharge tubes having means for eliminating the bubble effect
US5189343A (en) * 1991-08-27 1993-02-23 Everbrite, Inc. High frequency luminous tube power supply having neon-bubble and mercury-migration suppression
EP0547674A1 (fr) * 1991-12-16 1993-06-23 Koninklijke Philips Electronics N.V. Dispositif de communitation pour éliminer les striations
US5231333A (en) * 1990-11-14 1993-07-27 Neon Dynamics, Inc. Switching excitation supply for gas discharge tubes having means for eliminating the bubble effect

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4916362A (en) * 1988-04-05 1990-04-10 Neon Dynamics Corporation Excitation supply for gas discharge tubes
US5103138A (en) * 1990-04-26 1992-04-07 Orenstein Edward D Switching excitation supply for gas discharge tubes having means for eliminating the bubble effect
US5231333A (en) * 1990-11-14 1993-07-27 Neon Dynamics, Inc. Switching excitation supply for gas discharge tubes having means for eliminating the bubble effect
US5189343A (en) * 1991-08-27 1993-02-23 Everbrite, Inc. High frequency luminous tube power supply having neon-bubble and mercury-migration suppression
EP0547674A1 (fr) * 1991-12-16 1993-06-23 Koninklijke Philips Electronics N.V. Dispositif de communitation pour éliminer les striations

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2353153A (en) * 1999-07-26 2001-02-14 Microlights Ltd Discharge lamp ballast with reduced shock hazard
GB2353153B (en) * 1999-07-26 2002-05-15 Microlights Ltd Improvements in and relating to electric lights
WO2001037617A1 (fr) * 1999-11-17 2001-05-25 Koninklijke Philips Electronics N.V. Circuit de ballast
US6452343B2 (en) 1999-11-17 2002-09-17 Koninklijke Philips Electronics N.V. Ballast circuit
WO2001093643A1 (fr) * 2000-05-31 2001-12-06 Keith Billings Ballast de lampe permettant de reduire le courant d'interference
WO2001093644A3 (fr) * 2000-06-01 2002-02-28 Everbrite Inc Lampe a decharge gazeuse comprenant un circuit de protection de fuite
WO2002080288A3 (fr) * 2001-03-30 2002-12-27 Maxim Integrated Products Appareils et processus de source de courant pour diodes electroluminescentes
US6538394B2 (en) 2001-03-30 2003-03-25 Maxim Integrated Products, Inc. Current source methods and apparatus for light emitting diodes

Also Published As

Publication number Publication date
CN1060307C (zh) 2001-01-03
CN1134216A (zh) 1996-10-23
CA2173873C (fr) 2002-06-04
AU8128194A (en) 1995-05-22
CA2173873A1 (fr) 1995-05-04

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