EP0111956B1 - Circuit arrangement for operating high-pressure discharge lamps - Google Patents

Circuit arrangement for operating high-pressure discharge lamps Download PDF

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Publication number
EP0111956B1
EP0111956B1 EP83201696A EP83201696A EP0111956B1 EP 0111956 B1 EP0111956 B1 EP 0111956B1 EP 83201696 A EP83201696 A EP 83201696A EP 83201696 A EP83201696 A EP 83201696A EP 0111956 B1 EP0111956 B1 EP 0111956B1
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EP
European Patent Office
Prior art keywords
lamp
capacitor
circuit arrangement
current
diode
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.)
Expired
Application number
EP83201696A
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German (de)
French (fr)
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EP0111956A1 (en
Inventor
Hans Günter Ganser
Hans-Peter Dr. Stormberg
Ralf Dr. Schäfer
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Philips Intellectual Property and Standards GmbH
Koninklijke Philips NV
Original Assignee
Philips Patentverwaltung GmbH
Philips Gloeilampenfabrieken NV
Koninklijke Philips Electronics NV
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Priority to AT83201696T priority Critical patent/ATE23246T1/en
Publication of EP0111956A1 publication Critical patent/EP0111956A1/en
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Publication of EP0111956B1 publication Critical patent/EP0111956B1/en
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    • 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
    • H05B41/16—Circuit arrangements in which the lamp is fed by dc or by low-frequency ac, e.g. by 50 cycles/sec ac, or with network frequencies
    • H05B41/20—Circuit arrangements in which the lamp is fed by dc or by low-frequency ac, e.g. by 50 cycles/sec ac, or with network frequencies having no starting switch
    • H05B41/23—Circuit arrangements in which the lamp is fed by dc or by low-frequency ac, e.g. by 50 cycles/sec ac, or with network frequencies having no starting switch for lamps not having an auxiliary starting electrode
    • H05B41/231—Circuit arrangements in which the lamp is fed by dc or by low-frequency ac, e.g. by 50 cycles/sec ac, or with network frequencies having no starting switch for lamps not having an auxiliary starting electrode for high-pressure lamps

Definitions

  • the invention relates to a circuit arrangement for operating high-pressure gas discharge lamps with pulsating direct current, consisting of a full-wave rectifier connected to an AC voltage network, the direct voltage of which is supplied to the discharge lamp via a current limiter connected in series with it, the output of the full-wave rectifier being connected in series by a diode and a capacitor is bridged, which at least partially discharges via the lamp after every half cycle of the mains AC voltage.
  • a problem with the operation of high pressure gas discharge lamps is the initial ignition of the lamps, i.e. the starting of the cold lamps and the re-ignition after each zero crossing of the mains alternating current or every direct current pulse.
  • high re-ignition voltages e.g., during the warm-up phase, which, depending on the lamp size, takes between 30 seconds and 5 minutes after the initial ignition, 500 to 1000V, it may be necessary that these can no longer be supplied by the voltage source and therefore the lamp goes out.
  • Almost all components of the circuit arrangement e.g. Switching transistors and capacitors can be designed for this voltage.
  • the re-ignition of the lamps is improved in that the capacitor changes after every half cycle of the AC mains voltage, ie in the vicinity of the zero crossings of the AC mains voltage, discharged at least partially via the lamp via a thyristor.
  • a high voltage of approximately 200 to 300 V is required across this capacitor for a time of approximately 1 msec before and after the zero crossing of the AC voltage in order to avoid reignition difficulties.
  • this capacitor has a capacitance of 2.2 I IF.
  • Such a capacitor is relatively large in space and would be difficult to insert into a circuit arrangement which, for example, should be able to be integrated into the lamp itself, for example into the lamp base.
  • the invention has for its object to provide a circuit arrangement for operating high-pressure gas discharge lamps, which enables a low re-ignition voltage during the warm-up phase of the lamp and manages with relatively small components.
  • This object is achieved in a circuit arrangement of the type mentioned at the outset according to the invention in that the capacitor has a value of 10 nF to 1 Il F and in that a high-resistance resistor with respect to the current limiter is connected in the circuit between the diode-side end of this capacitor and the lamp .
  • the invention is based on the knowledge that, in order to avoid reignition difficulties, it is sufficient if a very small current flows in the discharge circuit between the capacitor and the lamp, which current is between 1 and 30 mA, depending on the lamp size. This is achieved by limiting the current through the lamp through the high resistance. At the same time, a substantial discharge of the now relatively small capacitor is avoided.
  • the current limiter can be an ohmic resistor which is connected in series with a further diode.
  • the high-resistance resistor is advantageously connected to the lamp via a switching transistor, which leads to a reduction in the power loss in the high-resistance resistor.
  • the current limiter can also be an electronic ballast, e.g. a chopper or a flyback converter.
  • a further diode is connected in series to the electronic ballast and the lamp-side end of the high-resistance resistor is connected between this further diode and the ballast.
  • a switching transistor usually connected in series with the lamp is conductive in the vicinity of the zero crossings of the AC line voltage, so that a current can then flow from the capacitor to the lamp via the high-resistance resistor.
  • a and B designate input terminals for connection to an AC voltage network of 220 V, 50 Hz.
  • a full-wave rectifier 1 with four diodes, which generates a pulsating direct current, is connected to these input terminals, possibly via a line filter.
  • a high-pressure gas discharge lamp 3, in particular a metal halide discharge lamp, is connected in series with a current limiter 2 to the output of the full-wave rectifier 1.
  • the current limiter 2 is an electronic ballast, such as it is described for example in US-A 3890537.
  • the output of the full-wave rectifier 1 is also bridged by a series connection of a diode 4 and a capacitor 5. Between the diode-side end of the capacitor 5 and the lamp 3, a high-resistance resistor 6 is connected to the current limiter 2.
  • the lamp 3 After the lamp 3 has been ignited for the first time, it is in a warm-up phase which, depending on the lamp size, takes between about 30 seconds and 5 minutes. During this warm-up phase, relatively high re-ignition voltages are required after each mains AC voltage zero crossing so that the lamp does not go out. However, these high re-ignition voltages cannot normally be supplied by the electronic ballast 2 during the zero crossing of the AC mains voltage. Rather, the capacitor 5 is provided for this purpose, which charges during the peaks of the mains AC voltage periods and at least partially discharges via the lamp 3 in the vicinity of the zero crossings of the mains AC voltage. If the capacitor 5 were connected directly to the lamp 3, discharge currents of more than 100 mA would flow, which would require a very large capacitor.
  • the high-impedance resistor 6 reduces these currents from the capacitor 5 to 1 to 30 mA, depending on the lamp size. Surprisingly, it has been found that, compared to the mean lamp current, this very small discharge current during the zero crossings of the AC mains voltage is sufficient to re-ignite the lamp 3 with a relatively low voltage during its warm-up phase.
  • the capacitor 5 need only have a capacitance of 10 nF to 1 I IF. In a practical exemplary embodiment with a 45 W metal halide discharge lamp, the capacitor 5 had a capacitance of 200 nF and the resistor 6 had a value of 300 kOhm.
  • the capacitor 5 is charged via the diode 4 to the peak value of the AC line voltage (about 300V).
  • a current of approximately 1 mA flows from the capacitor 5 via the resistor 6 through the lamp 3; in this case the capacitor 5 is not completely discharged.
  • 45 W metal halide lamps go through their warm-up phase without reignition problems.
  • a further diode 7 is connected upstream of the electronic ballast 2 and the lamp-side end of the high-resistance resistor 6 is connected between this further diode 7 and the ballast 2.
  • the high-resistance resistor 6 contributes to reducing the discharge current from the capacitor 5 via the ballast 2 through the lamp 3 during the zero crossings of the AC mains voltage.
  • the further diode 7 prevents a reverse current from the capacitor 5 to the full-wave rectifier 1.
  • the electronic ballast 2 is, for example, a forward converter, its switching transistor is turned on near the zero crossings of the AC line voltage, so that during this time a current can flow from the capacitor 5 via the high-resistance resistor 6 directly to the lamp 3. Outside the zero crossings of the AC line voltage, the switching transistor of the electronic ballast 2 usually only works with a pulse duty factor of about 30%, so that the current from the capacitor 5 via the high-resistance resistor 6 is also interrupted with this pulse duty factor.
  • the power loss in the high-resistance resistor 6 is reduced to 30%, which, however, has no disadvantages for the ignition behavior of the lamp 3, since the additional current from the capacitor 5 only has to flow through the lamp 3 in the vicinity of the zero crossings of the AC mains voltage.
  • the circuit arrangement according to FIG. 1 has an ohmic resistor 12 of approximately 250 ohms, which is connected in series with a further diode 7 to avoid reverse currents.
  • the high-resistance resistor 6 is connected to the lamp 3 via a switching transistor 8.
  • This switching transistor 8 is switched on and off via a control circuit 9.
  • the control circuit 9 is regulated by the rectified mains voltage. If the instantaneous value of this rectified mains voltage falls short of a value of z. B. 50 V, the switching transistor 8 is turned on so that an additional current can flow from the capacitor 5 through the high-resistance resistor 6 through the lamp.
  • the switching transistor 8 is switched non-conductive by the control circuit 9 and thus the current through the high-resistance resistor 6 is interrupted. Power losses in the high-resistance resistor 6 thus only occur during approximately 10% of the mains AC voltage period. In this circuit for a 45 W metal halide discharge lamp, the power loss in the high-resistance resistor 6 is usually below 0.1 W.

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  • Circuit Arrangements For Discharge Lamps (AREA)

Abstract

A circuit arrangement for operating a high-pressure gas discharge lamp (3) with a pulsatory direct current produced from an alternating voltage supply (A, B) via a full-wave rectifier (1). The output of the full-wave rectifier is shunted by a series arrangement of a diode (4) and a capacitor (5). The capacitor (5) has a value of 10 nF to 1 mu F and a resistor (6), which is high-ohmic with respect to a current limiter (2) in series with the lamp (3), is connected in a current circuit between the end of the capacitor facing the diode and the lamp (3). As a result, a low re-ignition voltage is attained during the head-up phase of the lamp.

Description

Die Erfindung betrifft eine Schaltungsanordnung zum Betrieb von Hochdruck-Gasentladungslampen mit pulsierendem Gleichstrom, bestehend aus einem an ein Wechselspannungsnetz angeschlossenenen Vollweggleichrichter, dessen Gleichspannung der Entladungslampe über einen mit ihr in Reihe liegenden Strombegrenzer zugeführt wird, wobei der Ausgang des Vollweggleichrichters durch eine Serienschaltung mit einer Diode und einem Kondensator überbrückt ist, der sich nach jeder Halbperiode der Netzwechselspannung wenigstens teilweise über die Lampe entlädt.The invention relates to a circuit arrangement for operating high-pressure gas discharge lamps with pulsating direct current, consisting of a full-wave rectifier connected to an AC voltage network, the direct voltage of which is supplied to the discharge lamp via a current limiter connected in series with it, the output of the full-wave rectifier being connected in series by a diode and a capacitor is bridged, which at least partially discharges via the lamp after every half cycle of the mains AC voltage.

Ein Problem beim Betrieb von Hochdruck-Gasentladungslampen ist die Erstzündung der Lampen, d.h. das Starten der kalten Lampen, und die Wiederzündung nach jedem Nulldurchgang des Netzwechselstromes bzw. jedem Gleichstromimpuls. Dies gilt an sich für alle Hochdruck-Gasentladungslampen, z.B. für Quecksilberdampf- oder Natriumdampf-Gasentladungslampen. Insbesondere aber bei Metallhalogenid-Entladungslampen können während der Aufwärmphase, die je nach Lampengrösse zwischen 30 sec und 5 Min. nach der Erstzündung dauert, derart hohe Wiederzündspannungen, z.B. von 500 bis 1000V, erforderlich sein, dass diese von der Spannungsquelle nicht mehr geliefert werden können und die Lampe deshalb verlöscht. Dabei müssen fast alle Bauelemente der Schaltungsanordnung, wie z.B. Schalttransistoren und Kondensatoren, für diese Spannung ausgelegt sein.A problem with the operation of high pressure gas discharge lamps is the initial ignition of the lamps, i.e. the starting of the cold lamps and the re-ignition after each zero crossing of the mains alternating current or every direct current pulse. This applies to all high pressure gas discharge lamps, e.g. for mercury vapor or sodium vapor gas discharge lamps. However, in particular in the case of metal halide discharge lamps, such high re-ignition voltages, e.g., during the warm-up phase, which, depending on the lamp size, takes between 30 seconds and 5 minutes after the initial ignition, 500 to 1000V, it may be necessary that these can no longer be supplied by the voltage source and therefore the lamp goes out. Almost all components of the circuit arrangement, e.g. Switching transistors and capacitors can be designed for this voltage.

Bei einer aus FR-A 2438406 bekannten Schaltungsanordnung dieser Art mit einer den Vollweggleichrichter überbrückenden Serienschaltung aus einer Diode und einem Kondensator wird die Wiederzündung der Lampen dadurch verbessert, dass sich der Kondensator nach jeder Halbperiode der Netzwechselspannung, d.h. in der Nähe der Nulldurchgänge der Netzwechselspannung, über einen Thyristor wenigstens teilweise über die Lampe entlädt. In der Aufwärmphase von Metallhalogenid-Lampen ist eine hohe Spannung von etwa 200 bis 300 V an diesem Kondensator während einer Zeit von etwa 1 msec vor und nach dem Nulldurchgang der Netzwechselspannung notwendig, um Wiederzündschwierigkeiten zu vermeiden. Bei der bekannten Schaltungsanordnung besitzt dieser Kondensator hierfür eine Kapazität von 2,2 IlF. Ein solcher Kondensator ist räumlich relativ gross und würde sich nur schwer in eine Schaltungsanordnung einfügen lassen, die z.B. in die Lampe selbst, z.B. in den Lampensockel, integrierbar sein soll.In a circuit arrangement of this type known from FR-A 2438406 with a series circuit bridging the full-wave rectifier comprising a diode and a capacitor, the re-ignition of the lamps is improved in that the capacitor changes after every half cycle of the AC mains voltage, ie in the vicinity of the zero crossings of the AC mains voltage, discharged at least partially via the lamp via a thyristor. In the warm-up phase of metal halide lamps, a high voltage of approximately 200 to 300 V is required across this capacitor for a time of approximately 1 msec before and after the zero crossing of the AC voltage in order to avoid reignition difficulties. In the known circuit arrangement, this capacitor has a capacitance of 2.2 I IF. Such a capacitor is relatively large in space and would be difficult to insert into a circuit arrangement which, for example, should be able to be integrated into the lamp itself, for example into the lamp base.

Der Erfindung liegt die Aufgabe zugrunde, eine Schaltungsanordnung zum Betrieb von Hochdruck-Gasentladungslampen zu schaffen, die eine niedrige Wiederzündspannung während der Aufwärmphase der Lampe ermöglicht und hierbei mit relativ kleinen Bauelementen auskommt.The invention has for its object to provide a circuit arrangement for operating high-pressure gas discharge lamps, which enables a low re-ignition voltage during the warm-up phase of the lamp and manages with relatively small components.

Diese Aufgabe wird bei einer Schaltungsanordnung eingangs erwähnter Art gemäss der Erfindung dadurch gelöst, dass der Kondensator einen Wert von 10 nF bis 1 IlF besitzt und dass in den Stromkreis zwischen dem diodenseitigen Ende dieses Kondensators und der Lampe ein gegenüber dem Strombegrenzer hochohmiger Widerstand geschaltet ist.This object is achieved in a circuit arrangement of the type mentioned at the outset according to the invention in that the capacitor has a value of 10 nF to 1 Il F and in that a high-resistance resistor with respect to the current limiter is connected in the circuit between the diode-side end of this capacitor and the lamp .

Die Erfindung geht von der Erkenntnis aus, dass es zur Vermeidung von Wiederzündschwierigkeiten ausreicht, wenn in dem Entladestromkreis zwischen Kondensator und Lampe ein verglichen mit dem mittleren Lampenstrom sehr kleiner Strom fliesst, der je nach Lampengrösse zwischen 1 und 30 mA liegt. Dies wird erreicht, indem der Strom durch die Lampe durch den hochohmigen Widerstand begrenzt wird. Gleichzeitig wird damit eine wesentliche Entladung des nunmehr relativ kleinen Kondensators vermieden. Der Strombegrenzer kann im einfachsten Fall ein ohmscher Widerstand sein, der mit einer weiteren Diode in Reihe geschaltet ist. Vorteilhafterweise ist der hochohmige Widerstand über einen Schalttransistor mit der Lampe verbunden, was zu einer Verringerung der Verlustleistung im hochohmigen Widerstand führt.The invention is based on the knowledge that, in order to avoid reignition difficulties, it is sufficient if a very small current flows in the discharge circuit between the capacitor and the lamp, which current is between 1 and 30 mA, depending on the lamp size. This is achieved by limiting the current through the lamp through the high resistance. At the same time, a substantial discharge of the now relatively small capacitor is avoided. In the simplest case, the current limiter can be an ohmic resistor which is connected in series with a further diode. The high-resistance resistor is advantageously connected to the lamp via a switching transistor, which leads to a reduction in the power loss in the high-resistance resistor.

Der Strombegrenzer kann aber auch ein elektronisches Vorschaltgerät, z.B. ein Zerhacker oder ein Sperr- bzw. Durchflusswandler, sein. Bei einer vorteilhaften Weiterbildung der Schaltungsanordnung nach der Erfindung ist dem elektronischen Vorschaltgerät eine weitere Diode in Reihe vorgeschaltet und das lampenseitige Ende des hochohmigen Widerstandes zwischen dieser weiteren Diode und dem Vorschaltgerät angeschlossen. Dabei ist ein bei derartigen Vorschaltgeräten üblicherweise in Reihe mit der Lampe liegender Schalttransistor in der Umgebung der Nulldurchgänge der Netzwechselspannung leitend, so dass dann ein Strom aus dem Kondensator über den hochohmigen Widerstand zur Lampe fliessen kann.The current limiter can also be an electronic ballast, e.g. a chopper or a flyback converter. In an advantageous development of the circuit arrangement according to the invention, a further diode is connected in series to the electronic ballast and the lamp-side end of the high-resistance resistor is connected between this further diode and the ballast. In such ballasts, a switching transistor usually connected in series with the lamp is conductive in the vicinity of the zero crossings of the AC line voltage, so that a current can then flow from the capacitor to the lamp via the high-resistance resistor.

Einige Ausführungsbeispiele der Erfindung werden nunmehr anhand der Zeichnung näher erläutert. Es zeigen:

  • Fig. 1 eine Schaltungsanordnung zum Betrieb einer Hochdruck-Gasentladungslampe mit einem elektronischen Vorschaltgerät als Strombegrenzer,
  • Fig.2 eine abgewandelte Schaltungsanordnung dieser Art und
  • Fig.3 eine Schaltungsanordnung zum Betrieb einer Hochdruck-Gasentladungslampe mit einem ohmschen Widerstand als Strombegrenzer.
Some embodiments of the invention will now be explained in more detail with reference to the drawing. Show it:
  • 1 shows a circuit arrangement for operating a high-pressure gas discharge lamp with an electronic ballast as a current limiter,
  • 2 shows a modified circuit arrangement of this type and
  • 3 shows a circuit arrangement for operating a high-pressure gas discharge lamp with an ohmic resistor as a current limiter.

Mit A und B sind Eingangsklemmen zum Anschliessen an ein Wechselspannungsnetz von 220 V, 50 Hz bezeichnet. An diese Eingangsklemmen ist, gegebenenfalls über ein Netzfilter, ein Vollweggleichrichter 1 mit vier Dioden angeschlossen, der einen pulsierenden Gleichstrom erzeugt. An den Ausgang des Vollweggleichrichters 1 ist in Reihe mit einem Strombegrenzer 2 eine Hochdruck-Gasentladungslampe 3, insbesondere eine Metallhalogenid-Entladungslampe, angeschlossen. Der Strombegrenzer 2 ist in diesem Fall ein elektronisches Vorschaltgerät, wie es z.B. in US-A 3890537 beschrieben ist. Der Ausgang des Vollweggleichrichters 1 ist ausserdem durch eine Serienschaltung aus einer Diode 4 und einem Kondensator 5 überbrückt. Zwischen das diodenseitige Ende des Kondensators 5 und die Lampe 3 ist ein gegenüber dem Strombegrenzer 2 hochohmiger Widerstand 6 geschaltet.A and B designate input terminals for connection to an AC voltage network of 220 V, 50 Hz. A full-wave rectifier 1 with four diodes, which generates a pulsating direct current, is connected to these input terminals, possibly via a line filter. A high-pressure gas discharge lamp 3, in particular a metal halide discharge lamp, is connected in series with a current limiter 2 to the output of the full-wave rectifier 1. In this case, the current limiter 2 is an electronic ballast, such as it is described for example in US-A 3890537. The output of the full-wave rectifier 1 is also bridged by a series connection of a diode 4 and a capacitor 5. Between the diode-side end of the capacitor 5 and the lamp 3, a high-resistance resistor 6 is connected to the current limiter 2.

Nach der Erstzündung der Lampe 3 befindet sich diese in einer Aufwärmphase, welche je nach Lampengrösse zwischen etwa 30 sec und 5 Min. dauert. Während dieser Aufwärmphase sind nach jedem Netzwechselspannungs-Nulldurchgang relativ hohe Wiederzündspannungen erforderlich, damit die Lampe nicht verlöscht. Diese hohen Wiederzündspannungen können aber normalerweise von dem elektronischen Vorschaltgerät 2 während des Nulldurchganges der Netzwechselspannung nicht geliefert werden. Dafür ist vielmehr der Kondensator 5 vorgesehen, der sich während der Spitzen der Netzwechselspannungsperioden auflädt und sich in der Nähe der Nulldurchgänge der Netzwechselspannung wenigstens teilweise über die Lampe 3 entlädt. Wäre der Kondensator 5 unmittelbar mit der Lampe 3 verbunden, würden hierbei Entladeströme von mehr als 100 mA fliessen, was einen sehr grossen Kondensator voraussetzen würde. Durch den hochohmigen Widerstand 6 werden diese Ströme aus dem Kondensator 5 je nach Lampengrösse auf 1 bis 30 mA verringert. Überraschenderweise hat sich herausgestellt, dass dieser verglichen mit dem mittleren Lampenstrom sehr kleine Entladestrom während der Nulldurchgänge der Netzwechselspannung ausreicht, um die Lampe 3 während ihrer Aufwärmphase mit einer relativ niedrigen Spannung wiederzuzünden. Hierfür braucht der Kondensator 5 nur eine Kapazität von 10 nF bis 1 IlF zu besitzen. Bei einem praktischen Ausführungsbeispiel mit einer 45 W-Metallhalogenid-Entladungslampe hatte der Kondensator 5 eine Kapazität von 200 nF und der Widerstand 6 einen Wert von 300 kOhm. Der Kondensator 5 wird über die Diode 4 auf den Spitzenwert der Netzwechselspannung (etwa 300V) aufgeladen. Beim Nulldurchgang der Netzwechselspannung fliesst aus dem Kondensator 5 über den Widerstand 6 durch die Lampe 3 ein Strom von etwa 1 mA; hierbei wird der Kondensator 5 nicht vollständig entladen. Mit dieser Anordnung durchlaufen 45 W-Metallhalogenidlampen ohne Wiederzündprobleme ihre Aufwärmphase.After the lamp 3 has been ignited for the first time, it is in a warm-up phase which, depending on the lamp size, takes between about 30 seconds and 5 minutes. During this warm-up phase, relatively high re-ignition voltages are required after each mains AC voltage zero crossing so that the lamp does not go out. However, these high re-ignition voltages cannot normally be supplied by the electronic ballast 2 during the zero crossing of the AC mains voltage. Rather, the capacitor 5 is provided for this purpose, which charges during the peaks of the mains AC voltage periods and at least partially discharges via the lamp 3 in the vicinity of the zero crossings of the mains AC voltage. If the capacitor 5 were connected directly to the lamp 3, discharge currents of more than 100 mA would flow, which would require a very large capacitor. The high-impedance resistor 6 reduces these currents from the capacitor 5 to 1 to 30 mA, depending on the lamp size. Surprisingly, it has been found that, compared to the mean lamp current, this very small discharge current during the zero crossings of the AC mains voltage is sufficient to re-ignite the lamp 3 with a relatively low voltage during its warm-up phase. For this purpose, the capacitor 5 need only have a capacitance of 10 nF to 1 I IF. In a practical exemplary embodiment with a 45 W metal halide discharge lamp, the capacitor 5 had a capacitance of 200 nF and the resistor 6 had a value of 300 kOhm. The capacitor 5 is charged via the diode 4 to the peak value of the AC line voltage (about 300V). When the AC mains voltage crosses zero, a current of approximately 1 mA flows from the capacitor 5 via the resistor 6 through the lamp 3; in this case the capacitor 5 is not completely discharged. With this arrangement, 45 W metal halide lamps go through their warm-up phase without reignition problems.

Bei der Schaltungsanordnung nach Fig. ist dem elektronischen Vorschaltgerät 2 eine weitere Diode 7 vorgeschaltet und ist das lampenseitige Ende des hochohmigen Widerstandes 6 zwischen dieser weiteren Diode 7 und dem Vorschaltgerät 2 angeschlossen. Auch hierbei trägt der hochohmige Widerstand 6 zur Verminderung des Entladestromes aus dem Kondensator 5 über das Vorschaltgerät 2 durch die Lampe 3 während der Nulldurchgänge der Netzwechselspannung bei. Die weitere Diode 7 unterbindet einen Rückstrom vom Kondensator 5 zum Vollweggleichrichter 1.In the circuit arrangement according to FIG. 1, a further diode 7 is connected upstream of the electronic ballast 2 and the lamp-side end of the high-resistance resistor 6 is connected between this further diode 7 and the ballast 2. Here, too, the high-resistance resistor 6 contributes to reducing the discharge current from the capacitor 5 via the ballast 2 through the lamp 3 during the zero crossings of the AC mains voltage. The further diode 7 prevents a reverse current from the capacitor 5 to the full-wave rectifier 1.

Wenn das elektronische Vorschaltgerät 2 zum Beispiel ein Durchflusswandler ist, so ist dessen Schalttransistor in der Nähe der Nulldurchgänge der Netzwechselspannung leitend geschaltet, so dass während dieser Zeit ein Strom aus dem Kondensator 5 über den hochohmigen Widerstand 6 direkt zur Lampe 3 fliessen kann. Ausserhalb der Nulldurchgänge der Netzwechselspannung arbeitet der Schalttransistor des elektronischen Vorschaltgerätes 2 üblicherweise nur mit einem Tastverhältnis von etwa 30%, so dass der Strom aus dem Kondensator 5 über den hochohmigen Widerstand 6 ebenfalls mit diesem Tastverhältnis unterbrochen wird. Dementsprechend verringert sich die Verlustleistung im hochohmigen Widerstand 6 auf 30%, was jedoch keine Nachteile auf das Zündverhalten der Lampe 3 hat, da der Zusatzstrom aus dem Kondensator 5 nur in der Nähe der Nulldurchgänge der Netzwechselspannung durch die Lampe 3 fliessen muss.If the electronic ballast 2 is, for example, a forward converter, its switching transistor is turned on near the zero crossings of the AC line voltage, so that during this time a current can flow from the capacitor 5 via the high-resistance resistor 6 directly to the lamp 3. Outside the zero crossings of the AC line voltage, the switching transistor of the electronic ballast 2 usually only works with a pulse duty factor of about 30%, so that the current from the capacitor 5 via the high-resistance resistor 6 is also interrupted with this pulse duty factor. Accordingly, the power loss in the high-resistance resistor 6 is reduced to 30%, which, however, has no disadvantages for the ignition behavior of the lamp 3, since the additional current from the capacitor 5 only has to flow through the lamp 3 in the vicinity of the zero crossings of the AC mains voltage.

Die Schaltungsanordnung nach Fig. besitzt im Gegensatz zur Schaltungsanordnung nach Fig. 1 als Strombegrenzer für die Lampe 3 einen ohmschen Widerstand 12 von etwa 250 Ohm, der mit einer weiteren Diode 7 zur Vermeidung von Rückströmen in Reihe liegt. Der hochohmige Widerstand 6 ist über einen Schalttransistor 8 mit der Lampe 3 verbunden. Dieser Schalttransistor 8 wird über eine Steuerschaltung 9 ein- und ausgeschaltet. Die Steuerschaltung 9 wird durch die gleichgerichtete Netzspannung geregelt. Unterschreitet der Momentanwert dieser gleichgerichteten Netzspannung in der Nähe der Nulldurchgänge der Netzwechselspannung einen Wert von z. B. 50 V, so wird der Schalttransistor 8 durchgeschaltet, damit ein Zusatzstrom aus dem Kondensator 5 über den hochohmigen Widerstand 6 durch die Lampe fliessen kann. Bei Momentanwerten der gleichgerichteten Netzspannung oberhalb von z.B. 50V, d.h. während des grössten Teils der Netzwechselspannungsperiode, wird der Schalttransistor 8 von der Steuerschaltung 9 nichtleitend geschaltet und damit der Strom durch den hochohmigen Widerstand 6 unterbrochen. Somit treten Verlustleistungen im hochohmigen Widerstand 6 nur während etwa 10% der Netzwechselspannungsperiode auf. Die Verlustleistung im hochohmigen Widerstand 6 liegt bei dieser Schaltung für eine 45 W-Metallhalogenid-Entladungslampe üblicherweise unter 0,1 W.In contrast to the circuit arrangement according to FIG. 1, as a current limiter for the lamp 3, the circuit arrangement according to FIG. 1 has an ohmic resistor 12 of approximately 250 ohms, which is connected in series with a further diode 7 to avoid reverse currents. The high-resistance resistor 6 is connected to the lamp 3 via a switching transistor 8. This switching transistor 8 is switched on and off via a control circuit 9. The control circuit 9 is regulated by the rectified mains voltage. If the instantaneous value of this rectified mains voltage falls short of a value of z. B. 50 V, the switching transistor 8 is turned on so that an additional current can flow from the capacitor 5 through the high-resistance resistor 6 through the lamp. At instantaneous values of the rectified mains voltage above e.g. 50V, i.e. During the major part of the mains AC voltage period, the switching transistor 8 is switched non-conductive by the control circuit 9 and thus the current through the high-resistance resistor 6 is interrupted. Power losses in the high-resistance resistor 6 thus only occur during approximately 10% of the mains AC voltage period. In this circuit for a 45 W metal halide discharge lamp, the power loss in the high-resistance resistor 6 is usually below 0.1 W.

Claims (5)

1. A circuit arrangement for operating highpressure gas discharge lamps with a pulsatory direct current comprising a full-wave rectifier, which is connected to an alternating voltage mains and whose direct voltage is supplied to the discharge lamp via a current limiter connected in series with it, the output of the full-wave rectifier being shunted by a series arrangement comprising a diode and a capacitor, which capacitor is discharged at least in part after each half period of the mains alternating voltage through the lamp, characterized in that the capacitor (5) has a value of 10 nF to 1 IlF and in that with respect to the current limiter (2; 12) a high-ohmic resistor (6) is connected in the current circuit between the end of this capacitor facing the diode and the lamp (3).
2. A circuit arrangement as claimed in Claim 1, characterized in that the current limiter is a ohmic resistor (12), which is connected in series with a further diode (7).
3. A circuit arrangement as claimed in Claim 1, characterized in that the current limiter is an electronic ballast unit (2).
4. A circuit arrangement as claimed in any one of Claims 1 to 3, characterized in that the high-ohmic resistor (6) is connected to the lamp (3) through a switching transistor (8).
5. A circuit arrangement as claimed in Claim 3, characterized in that a further diode (7) is connected in series in front of the electronic ballast unit (2) and the end of the high-ohmic resistor (6) facing the lamp is connected between this further diode and the ballast unit.
EP83201696A 1982-12-11 1983-12-01 Circuit arrangement for operating high-pressure discharge lamps Expired EP0111956B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT83201696T ATE23246T1 (en) 1982-12-11 1983-12-01 CIRCUIT ARRANGEMENT FOR OPERATION OF HIGH-PRESSURE GAS DISCHARGE LAMPS.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3245924 1982-12-11
DE19823245924 DE3245924A1 (en) 1982-12-11 1982-12-11 CIRCUIT ARRANGEMENT FOR OPERATING HIGH PRESSURE GAS DISCHARGE LAMPS

Publications (2)

Publication Number Publication Date
EP0111956A1 EP0111956A1 (en) 1984-06-27
EP0111956B1 true EP0111956B1 (en) 1986-10-29

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EP83201696A Expired EP0111956B1 (en) 1982-12-11 1983-12-01 Circuit arrangement for operating high-pressure discharge lamps

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US (1) US4816721A (en)
EP (1) EP0111956B1 (en)
JP (1) JPS59117095A (en)
AT (1) ATE23246T1 (en)
CA (1) CA1229128A (en)
DE (2) DE3245924A1 (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3517248A1 (en) * 1985-05-13 1986-11-13 Philips Patentverwaltung Gmbh, 2000 Hamburg CIRCUIT ARRANGEMENT FOR THE OPERATION OF GAS DISCHARGE LAMPS WITH HIGH FREQUENCY CURRENT
NL8701358A (en) * 1987-06-11 1989-01-02 Philips Nv SWITCHING DEVICE.
EP0478054B1 (en) * 1990-09-25 1997-08-06 Matsushita Electric Works, Ltd. Apparatus for operating discharge lamps
CA2198173A1 (en) * 1997-02-21 1998-08-21 Exacta Transformers Of Canada Ltd. Micro-controller-operated high intensity discharge lamp ballast system and method
WO2009101552A1 (en) * 2008-02-14 2009-08-20 Koninklijke Philips Electronics N.V. Device for controlling a discharge lamp
JP5836969B2 (en) * 2009-12-11 2015-12-24 コーニンクレッカ フィリップス エヌ ヴェＫｏｎｉｎｋｌｉｊｋｅ Ｐｈｉｌｉｐｓ Ｎ．Ｖ． Driver circuit that drives the load circuit

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Publication number Priority date Publication date Assignee Title
US3066243A (en) * 1959-11-02 1962-11-27 Engelhard Hanovia Inc Starting and operating circuit for high pressure arc lamps
US3376470A (en) * 1965-08-12 1968-04-02 Atomic Energy Commission Usa Capacitor discharge circuit for starting and sustaining a welding arc
US3403293A (en) * 1966-07-29 1968-09-24 Philco Ford Corp Starter circuit for three-electrode gaseous discharge device
US3780342A (en) * 1972-03-01 1973-12-18 Gen Electric Ballast apparatus for starting and operating arc lamps
JPS5410850B2 (en) * 1972-06-06 1979-05-10
US3890537A (en) * 1974-01-02 1975-06-17 Gen Electric Solid state chopper ballast for gaseous discharge lamps
NL179698B (en) * 1974-09-18 1986-05-16 Philips Nv GAS AND / OR VAPOR DISCHARGE HEATER.
NL7809907A (en) * 1978-10-02 1980-04-08 Philips Nv MIXING LIGHT DEVICE.
JPS5551630A (en) * 1978-10-09 1980-04-15 Ichikoh Ind Ltd Illuminator
US4350933A (en) * 1980-11-26 1982-09-21 Honeywell Inc. Two-wire ballast for fluorescent tube dimming
US4500812A (en) * 1983-02-14 1985-02-19 Gte Products Corporation Electronic ballast circuit

Also Published As

Publication number Publication date
JPS59117095A (en) 1984-07-06
US4816721A (en) 1989-03-28
CA1229128A (en) 1987-11-10
DE3367315D1 (en) 1986-12-04
DE3245924A1 (en) 1984-06-14
EP0111956A1 (en) 1984-06-27
ATE23246T1 (en) 1986-11-15

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