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Publication numberUS3917976 A
Publication typeGrant
Publication dateNov 4, 1975
Filing dateAug 26, 1974
Priority dateOct 11, 1967
Publication numberUS 3917976 A, US 3917976A, US-A-3917976, US3917976 A, US3917976A
InventorsJoe A Nuckolls
Original AssigneeGen Electric
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Starting and operating circuit for gaseous discharge lamps
US 3917976 A
Abstract
Operating circuits for gaseous discharge lamps, such as those of metal vapor type, having ballast devices of conventional type are provided with high voltage generating means for applying high voltage starting pulses on the lamp. The circuits comprise a charging capacitor and a voltage sensitive switch device forming a series discharge loop with a selected number of turns of the ballast coil winding at its output end, a resistor in series with the capacitor, and a choke coil in series with the resistor to provide improved ignition voltage and energy for starting lamps of relatively low operating voltage.
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Description  (OCR text may contain errors)

i 1 STARTING AND OPERATING CIRCUIT FOR GASEOUS DISCHARGE LAMPS [75] Inventor; Joe A. Nuckolls, Hendersonville,

[73] Assignee: General Electric Company 22 Filed: Aug. 26, 1974 {21] Appl. No: 500,631

Related US. Application Data [63] Continuation-in-part of Scr, No, 674,508, Oct, 11,

1967, abandoned.

[52] US. Cl. H 315/258; 3l5/DIG. 5; 315/183; 315/208; 315/240; 315/283 [51] Int. Cl. H058 41/16 [58] Field of Search 3l5/D1G. 5, 183, 208, 239, 315/240, 258, 283, 362

[56] References Cited UNlTED STATES PATENTS 3364.386 H1968 Segawa et al1 1. 3l5/DlGt 5 3,522,475 8/1970 Hashirnoto 315/239 Primary Examiner-R. V. Rolinec Assistant Examiner-Lawrence J Dahl Attorney, Agent, or Firm-Sidney Greenberg [57] ABSTRACT Operating circuits for gaseous discharge lamps, such as those of metal vapor type, having ballast devices of conventional type are provided with high voltage generating means for applying high voltage starting pulses on the lamp. The circuits comprise a charging capacitor and a voltage sensitive switch device forming a series discharge loop with a selected number of turns of the ballast coil winding at its output end, a resistor in series with the capacitor, and a choke coil in series with the resistor to provide improved ignition voltage and energy for starting lamps of relatively low operating voltage.

9 Claims, 2 Drawing Figures STARTING AND OPERATING CIRCUIT FOR GASEOUS DISCHARGE LAMPS This application is a continuation-impart of eo-pending application Ser. No, 674,508 filed Oct. ll, I967, now abandoned, and assigned to the same assignee as the present invention.

The present invention relates to discharge lamp operating and starting circuits and especially to discharge lamps requiring a starting voltage substantially higher than the operating voltage.

It is an object of the invention to provide a simple, reliable, and economical starting and operating circuit for gaseous discharge lamps which require high starting voltages.

It is a particular object of the invention to provide a starting and operating circuit for discharge lamps of the above described type which have relatively low operating voltage and input voltage from which it is relatively difficult to generate high ignition voltage.

It is still another object of the invention to provide a starting circuit of the described type which is slaved to the lamp instantaneous ignition requirements and which automatically ceases operation once the lamp has started.

Other objects and advantages will become apparent from the following description and the appended claims.

With the above objects in view, the present invention relates to a starting and operating circuit for gaseous discharge lamps comprising a source of alternating current, ballasting means connected at its input side to the alternating current source, discharge lamp means connected to the output side of the ballasting means, and high voltage starting means including a portion of the ballasting means connected to the latter at it output side for providing a high voltage starting pulse on the discharge lamp means, the high voltage starting means comprising a charging capacitor and a resistor connected in series across the discharge lamp means, voltage sensitive switch means having a predetermined breakdown voltage connected across the charging capacitor and the portion of the ballasting means and forming a series discharge loop therewith for generating high frequency starting pulses, and induction means connected in series with the charging capacitor and the resistor for providing effective impedance to the high frequency starting pulses generated by the series discharge loop.

The invention will be better understood from the following description taken in conjunction with the accompanying drawing, in which:

FIG. I is a circuit diagram ofa lamp starting and operating circuit in which the invention is embodied; and

FIG. 2 is a circuit diagram of a modification of the FIG. I circuit.

Referring now to the drawing, and particularly to FIG. 1, there is shown a starting and operating circuit for a gaseous discharge lamp 1, such as a sodium or other metal vapor lamp, which requires a relatively high voltage pulse in order to be ignited and which thereafter operates on a lower voltage. Lamp 1 is connected by line conductors 3 and 4 across terminals 2 of an alternating current source, with inductive reactance ballast 5 connected in series therewith to provide a current limiting impedance, as is conventional in discharge lamp circuits. In order to provide high voltage starting pulses, e.g., of 2 or 3 kilovolts, on lamp 1, there is provided in the FIG. I embodiment a high voltage pulse generator comprising capacitor 6 and resistor 7 connected in series across lamp 1 on the output side of re' actor 5, and a voltage sensitive symmetrical switch 8, such as a neon glow lamp, which is a bi-laterally conducting gas tube and which becomes conductive only upon application of a predetermined voltage thereon. Other types of voltage sensitive bi-laterally conducting switch devices may be used instead of a neon glow lamp, as, for example, oppositely poled parallel connected controlled rectifiers, Shockley diodes, triacs (a-c semiconductor switch with single control electrode) or other equivalent switch devices or circuits. As shown, glow lamp 8 is connected across capacitor 6 and a predetermined number of turns 9 of reactor ballast 5 at the output end thereof, so that glow lamp 8 is in series discharge relation with capacitor 6 and the tapped turns 9 of ballast 5 in series therewith.

The number of turns thus tapped off at the output end should be sufficient to completely couple in an auto-transformer action the high voltage across the entire winding of reactor 5. The actual number of turns involved dictates the pulse inductance of the discharge loop. If the inductance is too small, the peak current in the discharge loop is too large, resulting in high resistance voltage drops around the loop and high switch losses, thus lowering the high voltage magnitude and energy level applied to lamp I. In a typical arrangement in the embodiment illustrated, the ratio oftotal turns to tapped turns selected may be about 30 to l, which usually suffices to provide good coupling and adequate peak output voltage for starting lamp I.

Connected across terminals 2 at the input side of reactor ballast 5 is capacitor 10 which serves both as a high frequency bypass and a power factor improvement capacitor. Such a capacitor, however, is not always necessary.

In the operation of the described circuit, capacitor 6 is initially charged through resistor 7 by the input voltage from the alternating current source. As the voltage across capacitor 6 rises, it reaches the breakdown potential of neon glow lamp 8. When this occurs, capaci tor 6 discharges through tapped turns 9 placing, say, 275 volts across those turns, resulting in a step-up by reactor 5 acting as a pulse transformer to a voltage of, say, about 3300 volts which appears across the total reactor turns. Pulses of this high voltage level are thereby produced across lamp 1 by the pulse generating circuit described. The line side of reactor 5 is shorted at the pulse frequency by capacitor I0. Since the pulse voltage cannot rise across capacitor I0, it must rise across resistor 7. Hence the pulse voltage appears across discharge lamp 1 in the correct polarity on each half cycle until lamp 1 starts. Upon starting of lamp 1, the pulsing mechanism is disabled as a result of the voltage clamping action of the ignited lamp load and therefore the voltage buildup across capacitor 6 does not reach the breakdown level of neon lamp 8.

In the use of a circuit such as thus described, a difficulty is encountered where lamp 1 is of a type which has a relatively low operating voltage, such as a I50 watt high pressure sodium vapor lamp of known type, as compared to 400 watt or 250 watt gaseous discharge lamps of the same type. Whereas the 150 watt lamp has an operating voltage of about 55 volts, and in the circuit shown should have relatively low open-circuit-voltage such as volts to provide stable lamp operation,

the 400 watt and 250 watt lamps have operating voltages of about lUU volts and are typically operated at open-circuibvoltages of 208 volts or more. Where a low operating voltage lamp such as described is used, it is not feasible in the described circuit to adjust the value of resistor 7 in order to provide the necessary high voltage to ignite the lamp. Thus, if the value of resistor 7 is made relatively low in order to charge capaci tor 6 to a sufficiently high voltage to start the lamp, the resistor constitutes a load on the circuit which reduces the ignition voltage to an excessively low level which is insufficient to start the lamp. On the other hand, if resister 7 has too high a value, capacitor 6 does not become charged to a sufficiently high level to start the lamp.

in accordance with the present invention, these problems are overcome by placing an inductor 11, specifically a radio frequency choke (RFC) coil, in series with resistor 7 as shown in FIG. I. Inductor 11 presents a high impedance to the high frequency starting pulses generated by operation of the described series discharge loop, and a result sufficient impedance is pro vided during that operation to prevent undue loading of the starting pulse, Furthermore, inductor ll exhibits a low impedance to the 60 cycle current charging capacitor 6, and thus allows the capacitor to charge to the desired level.

In general, the described circuit is particularly useful for lamps having an operating voltage of about 45 to 65 volts, and wherein the open circuit voltage across the lamp is about 105 to 125 volts.

FIG. 2 shows the invention as employed in a lamp operating circuit having a different high voltage generating circuit. In this embodiment, a triac l2 replaces neon tube 8 and its control (gate) electrode 120 is connected to a voltage sensitive triggering device 13, such as the silicon bi-lateral switch (SBS) shown, or a bi-lateral trigger diode (diac). The firing of triac 12 is cort trolled in the illustrated embodiment by a circuit comprising resistor 14 and resistor 15 connected in series across triac [2, with S85 13 connected to the junction of resistor 14 and resistor l5, and capacitor l6 connected across resistor 15, so that triac 12, its gate electrode 120, SE [3 and capacitor 16 form a series discharge loop. This circuit provides for proper phase control of the triac firing so that the starting pulses occur at the optimum time in the alternating current cycle. it being understood by those skilled in the art that the timing of the trigger operation will be dependent upon the relative values of resistor 14 and resistor 15.

ln a typical circuit such as shown in FIG. 2, the components listed below will have the following values:

Triac l2 RCA No. 4066) 55$ [3 GE No. 2N4992 Capacitor I6 012 mfd 5'71. 100 VDC Resistor [4 68K ohms 1 5 new Resistor l5 5.6K ohms 5%, VzW

Capacitor 6 0.47 mfd t 400 VDC Resistor 7 33K ohms :t 5%, SW

RFC coil ll l2 mh, 35 mu Ballast 5 30 ohms, 3.3 amps, 247 turns total Ballast turns 9 8 turns While the invention has been described in connection with the use of bilateral (symmetrical) switches for providing starting pulses on each halfcycle it will be understood that, where desired or appropriate for providing starting pulses only on alternate halfcycles, a

unidirectional switch such as an SCR may be used in place of triac l2, and a unidirectional trigger device such as a Shockley diode would then be used in place of S 13.

It will also be understood that the positions of capaci tor 6 and switch 8 may be interchanged in appropriate situations where this is desired.

It will further be understood that various forms of inductive ballast devices could be used in the described circuit instead of the reactor ballast shown, as for example, the ballasts shown in the aforementioned c0- pending application, and accordingly the disclosure of the latter application relating to such other ballasts and associated parts is incorporated by reference herein.

Although the invention has particular utility where lamps of relatively low operating voltage are used, other types of lamps may be employed in the described circuits even though they operate at substantially higher voltages.

While the present invention has been described with reference to particular embodiments thereof, it will be understood that numerous modifications may be made by those skilled in the art without actually departing from the scope of the invention. Therefore, the appended claims are intended to cover all such equivalent variations as come within the true spirit and scope of the invention.

What 1 claim as new and desired to secure by Letters Patent of the United States is:

l. A starting and operating circuit for gaseous discharge lamps comprising a source of alternating current, ballasting means connected at its input side to said alternating current source, discharge lamp means connected to the output side of said ballasting means, and high voltage starting means including a portion of said ballasting means connected to said ballasting means at its output side for providing a high voltage starting pulse on said discharge lamp means, said high voltage starting means comprising a charging capacitor and a resistor connected in series across said discharge lamp means, voltage sensitive switch means having a predetermined breakdown voltage connected across said charging capacitor and said portion of said ballasting means and forming a series discharge loop therewith for generating high frequency starting pulses, and induetion means connected in series with said charging capacitor and said resistor for providing rapid charging of said charging capacitor and effective impedance to the high frequency starting pulses generated by said series discharge loop.

2. A circuit as defined in claim 1, said ballasting means comprising inductance coil means having a plurality of turns, said portion of said ballasting means comprising a predetermined number of turns of said in ductance coil means at its output side, said inductance coil means stepping up the voltage produced across said predetermined number of turns by operation of said discharge loop.

3. A circuit as defined in claim I, said induction means comprising a radio frequency choke coil.

4.. A circuit as defined in claim 3, said voltage sensitive switch means comprising a controlled semiconductor switch having a control electrode, and voltage sensitive trigger means connected to said control electrode and said charging capacitor for triggering the operation of said controlled switch.

5.. A circuit as defined in claim 4, wherein said switch means comprises a bi-lateral conducting switch and 7. A circuit as defined in claim 1, including a high frequency by-pass capacitor connected across said alternating current source on the input side of said ballasting meansv 8. A circuit as defined in claim I, wherein said dis charge lamp means comprises a lamp having an operat ing voltage of about 45 to 65 volts,

9. A circuit as defined in claim 8, wherein the opencircuit-voltage across said lamp is about to l25 volts.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3364386 *Nov 9, 1964Jan 16, 1968Tokyo Shibaura Electric CoPulse generating means for starting discharge lamps
US3522475 *Jun 7, 1968Aug 4, 1970Matsushita Electric Works LtdDischarge lamp starting device
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4005336 *Jan 3, 1975Jan 25, 1977Gte Sylvania IncorporatedHigh intensity discharge lamp starting circuit
US4015167 *Jun 25, 1975Mar 29, 1977The General Electric Company LimitedCircuits for operating electric discharge lamps
US4072878 *Jan 10, 1975Feb 7, 1978Westinghouse Electric CorporationStarting and operating apparatus for high pressure sodium lamp ballasts
US4101809 *May 26, 1977Jul 18, 1978General Electric CompanyDischarge lamp operating circuit
US4143304 *Oct 6, 1976Mar 6, 1979Westinghouse Electric Corp.Positive starting and operating apparatus for high-pressure sodium lamps
US4209730 *Jul 14, 1978Jun 24, 1980Larry McGee CompanyStarting circuit for gaseous discharge lamps
US4210850 *Jun 15, 1978Jul 1, 1980The General Electric Company LimitedCircuits for operating electric discharge lamps
US4275337 *Aug 8, 1979Jun 23, 1981General Electric CompanyStarting and operating circuit for gaseous discharge lamps
US4322660 *Jun 20, 1980Mar 30, 1982Westinghouse Electric Corp.Starting and operating apparatus for high-pressure sodium lamps
US4323821 *Jan 30, 1980Apr 6, 1982Central Electrical CompanyLuminaire converter
US4337417 *Aug 14, 1980Jun 29, 1982Westinghouse Electric Corp.Starting and operating apparatus for high-pressure sodium lamps
US4472015 *Dec 3, 1982Sep 18, 1984General Electric CompanyMultifunction connector
US4527098 *Jan 28, 1983Jul 2, 1985General Electric CompanyDiscrete starter for HID lamp
US4572988 *Aug 22, 1983Feb 25, 1986Industrial Design Associates, (Ida)High frequency ballast circuit
US4601753 *Sep 20, 1985Jul 22, 1986General Electric CompanyPowdered iron core magnetic devices
US4601765 *May 5, 1983Jul 22, 1986General Electric CompanyPowdered iron core magnetic devices
US4724362 *Dec 23, 1985Feb 9, 1988Gte Products CorporationHigh frequency lamp igniter using a spiral line pulse generator in combination with a series inductor-switch circuit
US4763044 *Apr 6, 1987Aug 9, 1988Hubbell IncorporatedStart, hot restart and operating lamp circuit
US4795945 *May 7, 1987Jan 3, 1989The Forest Electric CompanyStarting circuit for high intensity gaseous discharge lamps
US4808888 *Nov 28, 1986Feb 28, 1989Gte Products CorporationStarting circuit for gaseous discharge lamps
US4866347 *Sep 28, 1987Sep 12, 1989Hubbell IncorporatedCompact fluorescent lamp circuit
US4902943 *May 23, 1989Feb 20, 1990General Electric CompanyPlug-in starting aid
US4931699 *Jan 6, 1989Jun 5, 1990General Electric CompanyBallast system including a starting aid for a gaseous discharge lamp
US4950961 *Nov 28, 1986Aug 21, 1990Gte Products CorporationStarting circuit for gaseous discharge lamps
US5047694 *Jun 30, 1989Sep 10, 1991Hubbell IncorporatedLamp starting circuit
US5210471 *Oct 18, 1991May 11, 1993Hubbell IncorporatedControlled-current lamp starting ciruit
US5321338 *Jun 14, 1991Jun 14, 1994Hubbell IncorporatedLamp starting circuit
US5594308 *Aug 29, 1995Jan 14, 1997Hubbell IncorporatedHigh intensity discharge lamp starting circuit with automatic disablement of starting pulses
US5663612 *Apr 30, 1996Sep 2, 1997Hubbell IncorporatedApparatus for dimming discharge lamp having electromagnetic regulator with selectively tapped capacitance winding
US5825139 *Nov 2, 1995Oct 20, 1998Hubbell IncorporatedLamp driven voltage transformation and ballasting system
US5962988 *Nov 12, 1997Oct 5, 1999Hubbell IncorporatedMulti-voltage ballast and dimming circuits for a lamp drive voltage transformation and ballasting system
US6104147 *Oct 22, 1998Aug 15, 2000Matsushita Electric Works, Ltd.Pulse generator and discharge lamp lighting device using same
US6114816 *Nov 8, 1996Sep 5, 2000Hubbell IncorporatedLighting control system for discharge lamps
US6597128Oct 3, 2001Jul 22, 2003Hubbell IncorporatedRemote discharge lamp ignition circuitry
US7705544Nov 16, 2007Apr 27, 2010Universal Lighting Technologies, Inc.Lamp circuit with controlled ignition pulse voltages over a wide range of ballast-to-lamp distances
Classifications
U.S. Classification315/258, 315/283, 315/DIG.500, 315/183, 315/208, 315/240
International ClassificationH05B41/04
Cooperative ClassificationY10S315/05, H05B41/042
European ClassificationH05B41/04B