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EP0572585B1 - Device for operating a gas-discharge lamp - Google Patents

Device for operating a gas-discharge lamp Download PDF

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Publication number
EP0572585B1
EP0572585B1 EP92923352A EP92923352A EP0572585B1 EP 0572585 B1 EP0572585 B1 EP 0572585B1 EP 92923352 A EP92923352 A EP 92923352A EP 92923352 A EP92923352 A EP 92923352A EP 0572585 B1 EP0572585 B1 EP 0572585B1
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EP
European Patent Office
Prior art keywords
lamp
voltage converter
connection
voltage
output
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 - Lifetime
Application number
EP92923352A
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German (de)
French (fr)
Other versions
EP0572585A1 (en
Inventor
Ingo Gorille
Ulrich Drews
Wolfgang Jacob
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Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
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Publication of EP0572585A1 publication Critical patent/EP0572585A1/en
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Publication of EP0572585B1 publication Critical patent/EP0572585B1/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
    • H05B41/26—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
    • H05B41/288—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 and specially adapted for lamps without preheating electrodes, e.g. for high-intensity discharge lamps, high-pressure mercury or sodium lamps or low-pressure sodium lamps
    • H05B41/292—Arrangements for protecting lamps or circuits against abnormal operating conditions
    • H05B41/2928—Arrangements for protecting lamps or circuits against abnormal operating conditions for protecting the lamp against abnormal operating conditions
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S315/00—Electric lamp and discharge devices: systems
    • Y10S315/05—Starting and operating circuit for fluorescent lamp
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S315/00—Electric lamp and discharge devices: systems
    • Y10S315/07—Starting and control circuits for gas discharge lamp using transistors

Definitions

  • the invention relates to a device for operating a gas discharge lamp according to the preamble of the main claim.
  • An electronic ballast for operating a gas discharge lamp is known from the specialist magazine ELEKTOR, number 6, 1988, "Fluorescent lamp electronics", pages 14-19.
  • the ballast contains a voltage converter which converts a given input voltage, here for example the mains voltage, into a given AC output voltage.
  • a bridge circuit is connected, which is designed as a half bridge, in the diagonal of which the gas discharge lamp is arranged.
  • the voltage converter contains a transformer that ensures electrical isolation between the input-side mains voltage and the bridge circuit. Due to an unavoidable stray capacitance between the gas discharge lamp and parts arranged adjacent to the lamp, such as a lamp, for example, an average potential of zero volts will result between the lamp and the parts.
  • the invention has for its object to provide a device for operating a gas discharge lamp, which enables a long service life of the gas discharge lamp.
  • the device according to the invention is based on the knowledge that an average potential of zero volts between the lamp and at least one part arranged adjacent to the lamp, which can carry an electrical potential, is not sufficient in all cases, to reliably prevent unwanted ion migration, in particular diffusion of ions into the lamp body.
  • a part is, for example, a lamp holder or a lamp in which the lamp is installed.
  • the part is not limited to the lamp.
  • the part can generally be a part in the vicinity of the lamp, it being essential that this part can carry an electrical potential so that an electric field can occur between the lamp and the part. It is therefore not necessary for the part to be electrically conductive. Charge balancing only has to take place.
  • a particularly simple implementation of the voltage converter is possible with an inverse converter, in which the negative pole of an input DC voltage source is connected to that connection of the output at which the positive potential occurs.
  • This configuration is particularly advantageous when the negative pole of the input DC voltage source is connected to an electrical device ground, because often the part adjacent to the lamp is also connected to the device ground. In relation to the negative output voltage of the inverse converter, the part lying on the circuit ground then always has a positive potential.
  • Another advantageous embodiment provides for the implementation of the voltage converter as a converter with an isolating transformer.
  • the electrical isolation between the input DC voltage source and the bridge circuit enables the part adjacent to the lamp to be connected easily to the positive connection at the output of the voltage converter.
  • the device according to the invention is particularly suitable for operating high-pressure gas discharge lamps which are arranged in a motor vehicle headlight.
  • FIG. 1 shows an electronic ballast for a gas discharge lamp with a simple voltage converter without potential isolation
  • FIG. 2 shows an embodiment with an inverse converter without potential isolation
  • FIG. 3 shows an exemplary embodiment with a voltage converter with transformer potential isolation.
  • FIG. 1 shows a gas discharge lamp 10 which is arranged in a diagonal 11 of a bridge circuit 12.
  • the bridge 12 contains two switching means 13, 14; 15, 16, wherein the series connections are each connected between a first and second bridge input line 17, 18.
  • the bridge diagonal 11 lies between a connection of the switching means 13, 14 of the one series connection and the connection of the switching means 15, 15 of the other series connection.
  • the electronic ballast contains a voltage converter 19, which converts a given input voltage into a predetermined voltage occurring at the output 20 of the converter 19.
  • a battery is provided as an example of an input voltage source 21, the positive pole 22 of which is connected to a coil 23.
  • a voltage converter switching means 25 is present between another connection of the coil 23 and the negative pole 24 of the battery 21.
  • the anode connection of a diode 26 is located at the connection between the coil 23 and the voltage converter switching means 25.
  • the cathode of the diode 26 is connected to a first connection 27 at the output 20 of the voltage converter 19.
  • a positive potential occurs at the first connection 27 in comparison to a second connection 28 at the output 20 of the voltage converter 19.
  • the second connection 28 is connected both to the negative pole 24 of the battery 21 and to the voltage converter switching means 25.
  • a smoothing capacitor 29 is located between the first and the second connection 27, 28 at the output 20 of the voltage converter 19.
  • the first connection 27 at the output 20 is connected to the first bridge input line 17 and the second connection at the output 20 is connected to the second bridge input line 18.
  • a control circuit 30 is provided, which emits corresponding control signals.
  • the control circuit 30 is connected to the first terminal 27.
  • a part 31 adjacent to the lamp 10 is connected, which can carry an electrical potential and which is arranged such that between the lamp 10 and the part 31 electric field 32 can occur.
  • the potential of the part 31 is always positive compared to the potential occurring on the lamp 10.
  • FIG. 2 those parts that functionally correspond to the parts shown in FIG. 1 are each given the same reference numerals.
  • the arrangement of the coil 23 is interchanged with that of the voltage converter switching means 25.
  • the switching means 25 is therefore directly on the positive pole 22 of the battery 21, while the coil 23 is on the other terminal of the switching means 25 and leads from there to the negative pole 24 of the battery.
  • the connection of the diode 26 has also changed, whose anode in FIG. 2 lies at the first connection 27 of the output 20 of the voltage converter 19. If the capacitor 29 is a capacitor with a predetermined polarity, its connections in FIG. 2 must be interchanged with FIG.
  • the part 31 is connected in FIG. 2 to the second connection 28 of the output 20 of the voltage converter 19.
  • the second connection 28 has a positive potential with respect to the first connection 27.
  • the second connection 28 is connected to the negative pole 24 of the battery 21, which is simultaneously connected to a device ground 33.
  • FIG. 3 shows a further exemplary embodiment of an electronic ballast which differs from the circuit diagrams shown in FIGS. 1 and 2 in the configuration of the voltage converter 19.
  • Those parts shown in FIG. 3 that correspond to the parts shown in FIGS. 1 and 2 are given the same reference numerals in FIG. 3.
  • an isolating transformer 34 is present in FIG. 3, the primary winding 35 of which is connected on the one hand to the positive pole 22 of the battery 21 and on the other hand to the voltage converter switching means 25.
  • the switching means 25 is connected to the negative pole 24 of the battery 21, which is connected to the device ground 33.
  • a secondary winding 36 of the transformer 34 is connected on the one hand via the diode 26 to the first connection 27 and on the other hand directly to the second connection 28 at the output 20 of the voltage converter 19.
  • the cathode of the diode 26 is at the first terminal 27. With this polarity of the diode 26, the positive potential with respect to the second terminal 28 is at the first terminal 27 of the output 20.
  • the part 31 is connected to the first terminal 27.
  • the device according to the invention according to FIG. 1 works as follows:
  • the voltage converter 19 transforms the voltage of the source 21 into a voltage required to operate the gas discharge lamp 10.
  • the voltage converter 19 outputs a DC voltage at its output 20.
  • a (mains) alternating voltage is provided as source 21, which is first rectified before it is fed to the voltage converter.
  • the battery shown in the figures can also be provided as the source 21, for example, which has a given direct voltage.
  • the operation of both the voltage converter 19 shown in FIG. 1 and the configurations shown in the other two figures is based on the prior art mentioned at the outset, the technical book by U. TIETZE and CH. SCHENK, "Semiconductor Circuit Technology" referenced.
  • the inductance of the coil 23 and the capacitance of the capacitor 29 can be determined from the formulas in the specified literature.
  • the output voltage can essentially be determined by the ratio of the switched-on to the switched-off state of the voltage converter switching means 25, which receives the corresponding switch-on signals from the control circuit 13. The ratio determines the control circuit as a function of the output voltage of the voltage converter 19 occurring at the first connection 27.
  • the bridge circuit 12 is designed as an H bridge, in which two switching means 13, 14; 15, 16 are connected in series between the two bridge input lines 17, 18.
  • the switching means 13, 14; 15, 16, as well as the voltage converter switching means 25, are, for example, switching transistors, preferably field-effect transistors.
  • the lamp 10 is connected in the bridge diagonal 11, which lies between the two connecting lines of the one switching means 13, 14 and the other switching means 15, 16. Through a time control of the switching means 13, 14; 15, 16, the lamp 10 is operated with an alternating voltage, which the DC voltage at the output 20 of the voltage converter 19 is derived.
  • FIG. 1 shows the state in which the switching means 14, 15 are closed while the switching means 13, 16 are open. In the next cycle, the switching means 14, 15 are opened and the switching means 13, 16 are closed. In the control, care must be taken that the current flowing through the lamp 10 is free of mean values. This is achieved in that the switching times for the switching means 13, 14; 15, 16 are each of the same length.
  • a half-bridge circuit is also suitable, in which two switching means, which are connected in series, are each replaced by capacitors. Further components required for the operation of the lamp 10, for example for limiting the current flowing through the lamp 10 or for igniting the lamp 10, are not shown in the figures, since they are of secondary importance for the present invention.
  • the part 31 is, for example, a lamp holder or a lamp in which the lamp 10 is installed. If the lamp is made entirely of plastic, other parts outside the lamp can act as part 31.
  • an electric field 32 which has the mean value zero, will build up between the lamp 10 and an adjacent part 31 due to the stray capacitance mentioned.
  • This assumption is valid on the condition that the part 31 has no conductive connection to any circuit point of the circuit arrangement shown in FIG.
  • the part 31 is connected to the terminal 27 at the output 20 of the voltage converter 19, which has a positive potential with respect to the other terminal 28. This measure ensures that the mean potential at the lamp 10 is always negative compared to the positive potential of the part 31.
  • part 31 cannot be connected to first connection 27 at output 20 of voltage converter 19 become.
  • the configuration of the voltage converter 19 shown in FIG. 2 is particularly advantageously suitable.
  • a pole 22, 24 of the source 21, in the example the negative pole 24, is connected to the electrical device ground 33, which is also connected to the part 31.
  • the voltage converter 19 is implemented as an inverse converter, in which the polarity of an input voltage is converted into a reverse polarity at the output 20 of the converter 19.
  • the connection shown in FIG. 2 between the part 31 and the second connection 28 can already be provided during the implementation without the need for an additional connection. This is particularly the case if the part 31 is a lamp holder, a lamp or at least another part 31 connected to the electrical device mass 33.
  • the configuration of the voltage converter 19 shown in FIG. 3 has the advantage of potential isolation between the source 21 and the output 20 of the converter 19. This advantage is made possible by the isolating transformer 34.
  • a flyback converter circuit is shown as an example in FIG.
  • the particular advantage of the transformer isolation is that the part 31, regardless of whether it is connected to the electrical device ground 33 or an operating earth, can always be connected in a simple manner to the connection 27, 28 at the output 20 of the voltage converter 19, which has the positive potential with respect to the other terminal 27, 28.

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  • Circuit Arrangements For Discharge Lamps (AREA)
  • Dc-Dc Converters (AREA)

Abstract

Proposed is a device for operating a gas-discharge lamp (10) , the device having a voltage transformer (19), preferably a transformer inverter, to the output (20) of which a bridge circuit (12) is connected, the lamp (10) being connected in the diagonal (11) across the bridge. Adjacent to the lamp (10) is an element (31) which can carry an electrical potential and which is disposed such that an electric field (32) can be generated between the lamp (10) and the element (31). The element (31) is connected up to that output terminal (27, 28) of the voltage transformer (19) at which the potential is positive with respect to the other terminal (27, 28).

Description

Die Erfindung geht aus von einer Vorrichtung zum Betreiben einer Gasentladungslampe nach der Gattung des Hauptanspruchs. Aus der Fachzeitschrift ELEKTOR, Heft 6, 1988, "Leuchtstofflampen-Elektronik", Seiten 14 - 19 ist ein elektronisches Vorschaltgerät zum Betreiben einer Gasentladungslampe bekannt. Das Vorschaltgerät enthält einen Spannungswandler, der eine gegebene Eingangsspannung, hier beispielsweise die Netzspannung, in eine vorgegebene Ausgangswechselspannung umsetzt. Am Ausgang des Spannungswandlers ist eine Brückenschaltung angeschlossen, die als Halbbrücke ausgebildet ist, in deren Diagonale die Gasentladungslampe angeordnet ist. Der Spannungswandler enthält einen Transformator, der eine Potentialtrennung zwischen der eingangsseitigen Netzspannung und der Brückenschaltung sicherstellt. Bedingt durch eine unvermeidliche Streukapazität zwischen der Gasentladungslampe und benachbart zur Lampe angeordneten Teilen wie beispielsweise einer Leuchte, wird sich zwischen der Lampe und den Teilen ein mittleres Potential von Null Volt einstellen.The invention relates to a device for operating a gas discharge lamp according to the preamble of the main claim. An electronic ballast for operating a gas discharge lamp is known from the specialist magazine ELEKTOR, number 6, 1988, "Fluorescent lamp electronics", pages 14-19. The ballast contains a voltage converter which converts a given input voltage, here for example the mains voltage, into a given AC output voltage. At the output of the voltage converter, a bridge circuit is connected, which is designed as a half bridge, in the diagonal of which the gas discharge lamp is arranged. The voltage converter contains a transformer that ensures electrical isolation between the input-side mains voltage and the bridge circuit. Due to an unavoidable stray capacitance between the gas discharge lamp and parts arranged adjacent to the lamp, such as a lamp, for example, an average potential of zero volts will result between the lamp and the parts.

Weitere geeignete Spannungswandler zum Betreiben einer Gasentladungslampe sind aus dem Fachbuch von U. TIETZE und CH. SCHENK, "Halbleiter-Schaltungstechnik", 6. Auflage, 1983, Springer-Verlag, Seiten 545 - 552 bekannt. Beschrieben sind Grundlagenschaltungen von Spannungswandlern wie beispielsweise Aufwärts-Wandler und invertierende Wandler ohne Potentialtrennung sowie Eintakt-Sperrwandler, Eintakt-Durchflußwandler und Gegentakt-Wandler mit transformatorischer Potentialtrennung.Other suitable voltage converters for operating a gas discharge lamp are from the specialist book by U. TIETZE and CH. SCHENK, "Semiconductor Circuit Technology", 6th edition, 1983, Springer-Verlag, pages 545-552. Basic circuits of voltage converters are described, such as step-up converters and inverting converters without potential isolation, as well as single-ended flyback converters, single-ended flow converters and push-pull converters with transformer potential isolation.

Beim Betreiben der Gasentladungslampe ist darauf zu achten, daß keine durch die Lampe fließende Gleichstromkomponente auftritt, um Ionenwanderungen zu vermeiden. Bereits im Jahre 1938 wurde in dem Fachbuch von Dr. W. UYTERHOEVEN, "Elektrische Gasentladungslampen", Springer-Verlag, 1938, Seiten 249 - 252 darauf hingewiesen, daß die Lebensdauer von Gasentladungslampen, gezeigt am Beispiel von Natrium-Hochdrucklampen, unter anderem begrenzt ist durch die Wechselwirkung der Natrium-Ionen mit dem Lampenkörper.When operating the gas discharge lamp, make sure that no direct current component flows through the lamp in order to avoid ion migration. Already in 1938 Dr. W. UYTERHOEVEN, "Electrical gas discharge lamps", Springer-Verlag, 1938, pages 249-252 pointed out that the life of gas discharge lamps, shown using the example of high pressure sodium lamps, is limited, inter alia, by the interaction of sodium ions with the lamp body .

Der Erfindung liegt die Aufgabe zugrunde, eine Vorrichtung zum Betreiben einer Gasentladungslampe anzugeben, die eine hohe Lebensdauer der Gasentladungslampe ermöglicht.The invention has for its object to provide a device for operating a gas discharge lamp, which enables a long service life of the gas discharge lamp.

Die Aufgabe wird durch die im Hauptanspruch angegebenen Merkmale gelöst.The object is achieved by the features specified in the main claim.

Vorteile der ErfindungAdvantages of the invention

Der erfindungsgemäßen Vorrichtung liegt die Erkenntnis zugrunde, daß ein mittleres Potential von Null Volt zwischen der Lampe und wenigstens einem benachbart zur Lampe angeordneten Teil, das ein elektrisches Potential führen kann, nicht in allen Fällen ausreicht, um eine unerwünschte Ionenwanderung, insbesondere eine Diffusion von Ionen in den Lampenkörper zuverlässig zu verhindern. Ein derartiges Teil ist beispielsweise eine Lampenfassung oder eine Leuchte, in der die Lampe eingebaut ist. Das Teil ist jedoch nicht auf die Leuchte beschränkt. Das Teil kann allgemein ein Teil in der Umgebung der Lampe sein, wobei wesentlich ist, daß dieses Teil ein elektrisches Potential führen kann, so daß zwischen der Lampe und dem Teil ein elektrisches Feld auftreten kann. Es ist deshalb auch nicht erforderlich, daß das Teil elektrisch leitfähig ist. Es muß lediglich ein Ladungsausgleich stattfinden können.The device according to the invention is based on the knowledge that an average potential of zero volts between the lamp and at least one part arranged adjacent to the lamp, which can carry an electrical potential, is not sufficient in all cases, to reliably prevent unwanted ion migration, in particular diffusion of ions into the lamp body. Such a part is, for example, a lamp holder or a lamp in which the lamp is installed. However, the part is not limited to the lamp. The part can generally be a part in the vicinity of the lamp, it being essential that this part can carry an electrical potential so that an electric field can occur between the lamp and the part. It is therefore not necessary for the part to be electrically conductive. Charge balancing only has to take place.

Mit der erfindungsgemäßen Maßnahme, daß das Teil mit demjenigen Anschluß am Ausgang des Wandlers verbunden ist, an dem in Bezug zum anderen Anschluß das positive Potential auftritt, wird nach experimentellen Ergebnissen offensichtlich erreicht, daß die Diffusion von Ionen in den Lampenkörper zumindest reduziert ist. Damit erhöht sich die Lebensdauer der Gasentladungslampe, die einerseits durch eine Verfärbung oder Reduzierung der abgegebenen Strahlung und andererseits im Extremfall durch Lampenbruch gegeben ist.With the measure according to the invention that the part is connected to that connection at the output of the converter at which the positive potential occurs in relation to the other connection, it is obviously achieved according to experimental results that the diffusion of ions into the lamp body is at least reduced. This increases the service life of the gas discharge lamp, which is given on the one hand by discoloration or reduction in the radiation emitted and on the other hand in extreme cases by lamp breakage.

Vorteilhafte Weiterbildungen und Verbesserungen der erfindungsgemäßen Vorrichtung ergeben sich aus Unteransprüchen.Advantageous further developments and improvements of the device according to the invention result from subclaims.

Eine besonders einfache Realisierung des Spannungswandlers ist mit einem Inverswandler möglich, bei dem der negative Pol einer Eingangsgleichspannungsquelle mit demjenigen Anschluß des Ausgangs verbunden ist, an dem das positive Potential auftritt. Diese Ausgestaltung ist insbesondere bei einer Verbindung des negativen Poles der Eingangsgleichspannungsquelle mit einer elektrischen Gerätemasse vorteilhaft, weil häufig das der Lampe benachbarte Teil ebenfalls mit der Gerätemasse verbunden ist. Bezogen auf die negative Ausgangsspannung des Invers-Wandlers weist das an der Schaltungsmasse liegende Teil dann stets positives Potential auf.A particularly simple implementation of the voltage converter is possible with an inverse converter, in which the negative pole of an input DC voltage source is connected to that connection of the output at which the positive potential occurs. This configuration is particularly advantageous when the negative pole of the input DC voltage source is connected to an electrical device ground, because often the part adjacent to the lamp is also connected to the device ground. In relation to the negative output voltage of the inverse converter, the part lying on the circuit ground then always has a positive potential.

Eine andere vorteilhafte Ausgestaltung sieht die Realisierung des Spannungswandlers als Wandler mit einem Trenntransformator vor. Die Potentialtrennung zwischen der Eingangsgleichspannungsquelle und der Brückenschaltung ermöglicht den einfachen Anschluß des der Lampe benachbarten Teiles mit dem positiven Anschluß am Ausgang des Spannungswandlers.Another advantageous embodiment provides for the implementation of the voltage converter as a converter with an isolating transformer. The electrical isolation between the input DC voltage source and the bridge circuit enables the part adjacent to the lamp to be connected easily to the positive connection at the output of the voltage converter.

Die erfindungsgemäße Vorrichtung ist besonders geeignet zum Betreiben von Hochdruck-Gasentladungslampen, die in einem Kraftfahrzeug-Scheinwerfer angeordnet sind. In diesem Fall ist das der Lampe benachbarte Teil der Scheinwerfer. Bei einer Realisierung des Scheinwerfers vollständig aus Kunststoff tritt an die Stelle des Scheinwerfers die Kraftfahrzeug-Karosserie.The device according to the invention is particularly suitable for operating high-pressure gas discharge lamps which are arranged in a motor vehicle headlight. In this case, the part of the headlights that is adjacent to the lamp. If the headlamp is made entirely of plastic, the motor vehicle body takes the place of the headlamp.

Weitere vorteilhafte Weiterbildungen und Verbesserungen ergeben sich aus weiteren Unteransprüchen in Verbindung mit der folgenden Beschreibung.Further advantageous developments and improvements result from further subclaims in connection with the following description.

Zeichnungdrawing

Figur 1 zeigt ein elektronisches Vorschaltgerät für eine Gasentladungslampe mit einem einfachen Spannungswandler ohne Potentialtrennung, Figur 2 zeigt ein Ausführungsbeispiel mit einem Invers-Wandler ohne Potentialtrennung und Figur 3 zeigt ein Ausführungsbeispeil mit einem Spannungswandler mit transformatorischer Potentialtrennung.FIG. 1 shows an electronic ballast for a gas discharge lamp with a simple voltage converter without potential isolation, FIG. 2 shows an embodiment with an inverse converter without potential isolation and FIG. 3 shows an exemplary embodiment with a voltage converter with transformer potential isolation.

In Figur 1 ist eine Gasentladungslampe 10 gezeigt, die in einer Diagonale 11 einer Brückenschaltung 12 angeordnet ist. Die Brücke 12 enthält jeweils zwei in Serie geschaltete Schaltmittel 13, 14; 15, 16, wobei die Serienschaltungen jeweils zwischen einer ersten und zweiten Brückeneingangsleitung 17, 18 geschaltet sind. Die Brückendiagonale 11 liegt zwischen einer Verbindung der Schaltmittel 13, 14 der einen Serienschaltung und der Verbindung der Schaltmittel 15, 15 der anderen Serienschaltung.FIG. 1 shows a gas discharge lamp 10 which is arranged in a diagonal 11 of a bridge circuit 12. The bridge 12 contains two switching means 13, 14; 15, 16, wherein the series connections are each connected between a first and second bridge input line 17, 18. The bridge diagonal 11 lies between a connection of the switching means 13, 14 of the one series connection and the connection of the switching means 15, 15 of the other series connection.

Das elektronische Vorschaltgerät enthält einen Spannungswandler 19, der eine gegebene Eingangsspannung in eine am Ausgang 20 des Wandlers 19 auftretende vorgegebene Spannung umsetzt. In Figur 1 ist als Beispiel einer Eingangsspannungsquelle 21 eine Batterie vorgesehen, deren positiver Pol 22 mit einer Spule 23 verbunden ist. Zwischen einem anderen Anschluß der Spule 23 und dem negativen Pol 24 der Batterie 21 ist ein Spannungswandler-Schaltmittel 25 vorhanden. An der Verbindung zwischen der Spule 23 und dem Spannungswandler-Schaltmittel 25 liegt der Anodenanschluß einer Diode 26. Die Kathode der Diode 26 ist mit einem ersten Anschluß 27 am Ausgang 20 des Spannungswandlers 19 verbunden. Am ersten Anschluß 27 tritt ein positives Potential im Vergleich zu einem zweiten Anschluß 28 am Ausgang 20 des Spannungswandlers 19 auf. Der zweite Anschluß 28 ist sowohl mit dem negativen Pol 24 der Batterie 21 als auch mit dem Spannungswandler-Schaltmittel 25 verbunden. Zwischen dem ersten und dem zweiten Anschluß 27, 28 am Ausgang 20 des Spannungswandlers 19 liegt ein Glättungskondensator 29.The electronic ballast contains a voltage converter 19, which converts a given input voltage into a predetermined voltage occurring at the output 20 of the converter 19. In FIG. 1, a battery is provided as an example of an input voltage source 21, the positive pole 22 of which is connected to a coil 23. A voltage converter switching means 25 is present between another connection of the coil 23 and the negative pole 24 of the battery 21. The anode connection of a diode 26 is located at the connection between the coil 23 and the voltage converter switching means 25. The cathode of the diode 26 is connected to a first connection 27 at the output 20 of the voltage converter 19. A positive potential occurs at the first connection 27 in comparison to a second connection 28 at the output 20 of the voltage converter 19. The second connection 28 is connected both to the negative pole 24 of the battery 21 and to the voltage converter switching means 25. A smoothing capacitor 29 is located between the first and the second connection 27, 28 at the output 20 of the voltage converter 19.

Der erste Anschluß 27 am Ausgang 20 ist verbunden mit der ersten Brückeneingangsleitung 17 und der zweite Anschluß am Ausgang 20 ist verbunden mit der zweiten Brückeneingangsleitung 18. Für eine elektronische Betätigung der Schaltmittel 13, 14; 15, 16 und des Spannungswandler-Schaltmittels 25 ist eine Steuerschaltung 30 vorgesehen, die entsprechende Steuersignale abgibt. Die Steuerschaltung 30 ist mit dem ersten Anschluß 27 verbunden.The first connection 27 at the output 20 is connected to the first bridge input line 17 and the second connection at the output 20 is connected to the second bridge input line 18. For an electronic actuation of the switching means 13, 14; 15, 16 and the voltage converter switching means 25, a control circuit 30 is provided, which emits corresponding control signals. The control circuit 30 is connected to the first terminal 27.

Am ersten Anschluß 27 am Ausgang 20 des Spannungwandlers 19, an dem das positive Potential auftritt, ist ein der Lampe 10 benachbartes Teil 31 angeschlossen, das ein elektrisches Potential führen kann und das derart angeordnet ist, daß zwischen der Lampe 10 und dem Teil 31 ein elektrisches Feld 32 auftreten kann. Das Potential des Teils 31 ist stets positiv gegenüber dem an der Lampe 10 auftretenden Potential.At the first terminal 27 at the output 20 of the voltage converter 19, at which the positive potential occurs, a part 31 adjacent to the lamp 10 is connected, which can carry an electrical potential and which is arranged such that between the lamp 10 and the part 31 electric field 32 can occur. The potential of the part 31 is always positive compared to the potential occurring on the lamp 10.

In Figur 2 sind diejenigen Teile, die mit den in Figur 1 gezeigten Teilen funktionell übereinstimmen, jeweils mit denselben Bezugszeichen angegeben. Der wesentliche Unterschied zwischen dem in Figur 1 und dem in Figur 2 gezeigten Schaltbild eines elektronischen Vorschaltgerätes liegt in der unterschiedlichen Ausgestaltung des Spannungswandlers 19. In Figur 2 ist gegenüber Figur 1 die Anordnung der Spule 23 mit der des Spannungswandler-Schaltmittels 25 vertauscht. Das Schaltmittel 25 liegt demnach unmittelbar am positiven Pol 22 der Batterie 21, während die Spule 23 am anderen Anschluß des Schaltmittels 25 liegt und von dort zum negativen Pol 24 der Batterie führt. Geändert hat sich auch die Verschaltung der Diode 26, deren Anode in Figur 2 am ersten Anschluß 27 des Ausgangs 20 des Spannungwandlers 19 liegt. Sofern der Kondensator 29 ein Kondensator mit vorgegebener Polarität ist, müssen seine Anschlüsse in Figur 2 gegenüber Figur 1 vertauscht werden. Das Teil 31 ist in Figur 2 mit dem zweiten Anschluß 28 des Ausgangs 20 des Spannungswandlers 19 verbunden. Der zweite Anschluß 28 weist ein positives Potential gegenüber dem ersten Anschluß 27 auf. Der zweite Anschluß 28 ist mit dem negativen Pol 24 der Batterie 21 verbunden, der gleichzeitig an eine Gerätemasse 33 gelegt ist.In FIG. 2, those parts that functionally correspond to the parts shown in FIG. 1 are each given the same reference numerals. The essential difference between the circuit diagram of an electronic ballast shown in FIG. 1 and FIG. 2 lies in the different design of the voltage converter 19. In FIG. 2, the arrangement of the coil 23 is interchanged with that of the voltage converter switching means 25. The switching means 25 is therefore directly on the positive pole 22 of the battery 21, while the coil 23 is on the other terminal of the switching means 25 and leads from there to the negative pole 24 of the battery. The connection of the diode 26 has also changed, whose anode in FIG. 2 lies at the first connection 27 of the output 20 of the voltage converter 19. If the capacitor 29 is a capacitor with a predetermined polarity, its connections in FIG. 2 must be interchanged with FIG. The part 31 is connected in FIG. 2 to the second connection 28 of the output 20 of the voltage converter 19. The second connection 28 has a positive potential with respect to the first connection 27. The second connection 28 is connected to the negative pole 24 of the battery 21, which is simultaneously connected to a device ground 33.

In Figur 3 ist ein weiteres Ausführungsbeispiel eines elektronischen Vorschaltgerätes gezeigt, das sich gegenüber den in dem Figuren 1 und 2 gezeigten Schaltbildern in der Ausgestaltung des Spannungswandlers 19 unterscheidet. Diejenigen in Figur 3 gezeigten Teile, die mit den in Figuren 1 und 2 gezeigten Teilen korrespondieren, sind in Figur 3 mit denselben Bezugszeichen angegeben. Anstelle der in den Figuren 1 und 2 gezeigten Spule 23 ist in Figur 3 ein Trenntransformator 34 vorhanden, dessen Primärwicklung 35 einerseits mit dem positiven Pol 22 der Batterie 21 und andererseits mit dem Spannungswandler-Schaltmittel 25 verbunden ist. Das Schaltmittel 25 ist mit dem negativen Pol 24 der Batterie 21 verbunden, der an die Gerätemasse 33 gelegt ist. Eine Sekundärwicklung 36 des Transformators 34 ist einerseits über die Diode 26 mit dem ersten Anschluß 27 und andererseits unmittelbar mit dem zweiten Anschluß 28 am Ausgang 20 des Spannungswandlers 19 verbunden. Die Kathode der Diode 26 liegt am ersten Anschluß 27. Bei dieser Polarität der Diode 26 liegt am ersten Anschluß 27 des Ausgangs 20 das positive Potential in Bezug auf den zweiten Anschluß 28. Das Teil 31 ist mit dem ersten Anschluß 27 verbunden.FIG. 3 shows a further exemplary embodiment of an electronic ballast which differs from the circuit diagrams shown in FIGS. 1 and 2 in the configuration of the voltage converter 19. Those parts shown in FIG. 3 that correspond to the parts shown in FIGS. 1 and 2 are given the same reference numerals in FIG. 3. Instead of the coil 23 shown in FIGS. 1 and 2, an isolating transformer 34 is present in FIG. 3, the primary winding 35 of which is connected on the one hand to the positive pole 22 of the battery 21 and on the other hand to the voltage converter switching means 25. The switching means 25 is connected to the negative pole 24 of the battery 21, which is connected to the device ground 33. A secondary winding 36 of the transformer 34 is connected on the one hand via the diode 26 to the first connection 27 and on the other hand directly to the second connection 28 at the output 20 of the voltage converter 19. The cathode of the diode 26 is at the first terminal 27. With this polarity of the diode 26, the positive potential with respect to the second terminal 28 is at the first terminal 27 of the output 20. The part 31 is connected to the first terminal 27.

Die erfindungsgemäße Vorrichtung gemäß Figur 1 arbeitet folgendermaßen:The device according to the invention according to FIG. 1 works as follows:

Der Spannungswandler 19 transformiert die Spannung der Quelle 21 in eine zum Betreiben der Gasentladungslampe 10 erforderliche Spannung. Der Spannungswandler 19 gibt an seinem Ausgang 20 eine Gleichspannung ab. Als Quelle 21 ist beispielsweise eine (Netz-)Wechselspannung vorgesehen, die zunächst gleichgerichtet wird, bevor sie dem Spannungswandler zugeleitet wird. Als Quelle 21 kann auch beispielsweise die in den Figuren gezeigte Batterie vorgesehen sein, die unmittelbar eine gegebene Gleichspannung aufweist. Hinsichtlich der Arbeitsweise sowohl des in Figur 1 gezeigten Spannungswandlers 19 als auch der in den beiden anderen Figuren gezeigten Ausgestaltungen wird auf den eingangs genannten Stand der Technik, dem Fachbuch von U. TIETZE und CH. SCHENK, "Halbleiter-Schaltungstechnik" verwiesen. Der in Figur 1 gezeigte Spannungswandler 19 ist demzufolge beispielsweise als Aufwärts-Wandler ausgestaltet, wobei zwischen der Batterie 21 und dem Ausgang 20 keine Potentialtrennung vorgesehen ist. Die Induktivität der Spule 23 sowie die Kapazität des Kondensators 29 können aus den Formeln in der angegebenen Literaturstelle ermittelt werden. Die Ausgangsspannung ist im wesentlichen durch das Verhältnis von eingeschaltetem zu ausgeschaltetem Zustand des Spannungswandler-Schaltmittels 25 festlegbar, das entsprechende Einschaltsignale von der Steuerschaltung 13 zugeführt erhält. Das Verhältnis legt die Steuerschaltung in Abhängigkeit von der am ersten Anschluß 27 auftretenden Ausgangsspannung des Spannungswandlers 19 fest.The voltage converter 19 transforms the voltage of the source 21 into a voltage required to operate the gas discharge lamp 10. The voltage converter 19 outputs a DC voltage at its output 20. For example, a (mains) alternating voltage is provided as source 21, which is first rectified before it is fed to the voltage converter. The battery shown in the figures can also be provided as the source 21, for example, which has a given direct voltage. Regarding The operation of both the voltage converter 19 shown in FIG. 1 and the configurations shown in the other two figures is based on the prior art mentioned at the outset, the technical book by U. TIETZE and CH. SCHENK, "Semiconductor Circuit Technology" referenced. The voltage converter 19 shown in FIG. 1 is accordingly designed, for example, as a step-up converter, no potential separation being provided between the battery 21 and the output 20. The inductance of the coil 23 and the capacitance of the capacitor 29 can be determined from the formulas in the specified literature. The output voltage can essentially be determined by the ratio of the switched-on to the switched-off state of the voltage converter switching means 25, which receives the corresponding switch-on signals from the control circuit 13. The ratio determines the control circuit as a function of the output voltage of the voltage converter 19 occurring at the first connection 27.

Die an den beiden Anschlüssen 27, 28 am Ausgang 20 des Spannungswandlers 19 auftretende Gleichspannung wird über die beiden Brückeneingangsleitungen 17, 18 der Brückenschaltung 12 zugeführt. Die Brückenschaltung 12 ist im gezeigten Ausführungsbeispiel als H-Brücke ausgebildet, bei der jeweils zwei Schaltmittel 13, 14; 15, 16 zwischen den beiden Brückeneingangsleitungen 17, 18 in Serie geschaltet sind. Die Schaltmittel 13, 14; 15, 16, ebenso wie das Spannungswandler-Schaltmittel 25, sind beispielsweise Schalttransistoren, vorzugsweise Feldeffekt-Transistoren. Die Lampe 10 ist in der Brückendiagonale 11 angeschlossen, die zwischen den beiden Verbindungsleitungen der einen Schaltmittel 13, 14 und der anderen Schaltmittel 15, 16 liegt. Durch eine von der Steuerschaltung 30 vorgegebene zeitliche Steuerung der Schaltmittel 13, 14; 15, 16 wird die Lampe 10 mit einer Wechselspannung betrieben, die von der am Ausgang 20 des Spannungswandlers 19 liegenden Gleichspannung abgeleitet ist. In Figur 1 ist der Zustand gezeigt, bei dem die Schaltmittel 14, 15 geschlossen sind, während die Schaltmittel 13, 16 geöffnet sind. Im nächsten Arbeitstakt werden die Schaltmittel 14, 15 geöffnet und die Schaltmittel 13, 16 geschlossen. Bei der Steuerung ist darauf zu achten, daß der durch die Lampe 10 fließende Strom mittelwertfrei ist. Dies wird dadurch erreicht, daß die Schaltzeiten für die Schaltmittel 13, 14; 15, 16 jeweils gleich lang sind. Anstelle der in Figur 1 gezeigten Brückenschaltung 12 mit vier Schaltmitteln 13, 14; 15, 16 ist auch eine Halbbrückenschaltung geeignet, bei der zwei Schaltmittel, die in Serie geschaltet sind, jeweils durch Kondensatoren ersetzt sind. Weitere, für den Betrieb der Lampe 10 erforderliche Komponenten, beispielsweise zur Begrenzung des durch die Lampe 10 fließenden Stroms oder zum Zünden der Lampe 10, sind in den Figuren nicht gezeigt, da sie für die vorliegende Erfindung untergeordnete Bedeutung haben.The DC voltage occurring at the two connections 27, 28 at the output 20 of the voltage converter 19 is supplied to the bridge circuit 12 via the two bridge input lines 17, 18. In the exemplary embodiment shown, the bridge circuit 12 is designed as an H bridge, in which two switching means 13, 14; 15, 16 are connected in series between the two bridge input lines 17, 18. The switching means 13, 14; 15, 16, as well as the voltage converter switching means 25, are, for example, switching transistors, preferably field-effect transistors. The lamp 10 is connected in the bridge diagonal 11, which lies between the two connecting lines of the one switching means 13, 14 and the other switching means 15, 16. Through a time control of the switching means 13, 14; 15, 16, the lamp 10 is operated with an alternating voltage, which the DC voltage at the output 20 of the voltage converter 19 is derived. FIG. 1 shows the state in which the switching means 14, 15 are closed while the switching means 13, 16 are open. In the next cycle, the switching means 14, 15 are opened and the switching means 13, 16 are closed. In the control, care must be taken that the current flowing through the lamp 10 is free of mean values. This is achieved in that the switching times for the switching means 13, 14; 15, 16 are each of the same length. Instead of the bridge circuit 12 shown in Figure 1 with four switching means 13, 14; 15, 16, a half-bridge circuit is also suitable, in which two switching means, which are connected in series, are each replaced by capacitors. Further components required for the operation of the lamp 10, for example for limiting the current flowing through the lamp 10 or for igniting the lamp 10, are not shown in the figures, since they are of secondary importance for the present invention.

Aufgrund von Streukapazitäten zwischen der Lampe und wenigstens einem, der Lampe 10 benachbarten Teil 31 kann sich zwischen dem Teil 31 und der Lampe 10 ein elektrisches Feld aufbauen. Das Teil 31 ist beispielsweise eine Lampenfassung oder eine Leuchte, in welcher die Lampe 10 eingebaut ist. Sofern die Leuchte vollständig aus Kunststoff hergestellt ist, können auch weitere Teile außerhalb der Leuchte als Teil 31 wirken.Due to stray capacitances between the lamp and at least one part 31 adjacent to the lamp 10, an electric field can build up between the part 31 and the lamp 10. The part 31 is, for example, a lamp holder or a lamp in which the lamp 10 is installed. If the lamp is made entirely of plastic, other parts outside the lamp can act as part 31.

Bei dem in Figur 1 gezeigten Ausführungsbeispiel des elektronischen Vorschaltgerätes wird sich aufgrund der erwähnten Streukapazität zwischen der Lampe 10 und einem benachbart angeordneten Teil 31 ein elektrisches Feld 32 aufbauen, das den Mittelwert Null aufweist. Diese Annahme gilt unter der Voraussetzung, daß das Teil 31 keine leitende Verbindung mit irgendeinem Schaltungspunkt der in Figur 1 gezeigten Schaltungsanordnung aufweist. Erfindungsgemäß ist vorgesehen, daß das Teil 31 mit dem Anschluß 27 am Ausgang 20 des Spannungswandlers 19 angeschlossen ist, der ein positives Potential in Bezug auf den anderen Anschluß 28 aufweist. Mit dieser Maßnahme ist sichergestellt, daß das mittlere Potential an der Lampe 10 stets negativ ist im Vergleich zum positiven Potential des Teils 31. Es wurde experimentell festgestellt, daß mit dieser Maßnahme ein vorzeitiges Altern der Lampe 10 zuverlässig verhindert werden kann, wobei der Effekt darauf beruhen dürfte, daß das positive Potential der Umgebung der Lampe 10 die in der Lampe auftretenden Ionen vom Lampengefäß fernhält und in das Plasma drückt.In the exemplary embodiment of the electronic ballast shown in FIG. 1, an electric field 32, which has the mean value zero, will build up between the lamp 10 and an adjacent part 31 due to the stray capacitance mentioned. This assumption is valid on the condition that the part 31 has no conductive connection to any circuit point of the circuit arrangement shown in FIG. According to the invention provided that the part 31 is connected to the terminal 27 at the output 20 of the voltage converter 19, which has a positive potential with respect to the other terminal 28. This measure ensures that the mean potential at the lamp 10 is always negative compared to the positive potential of the part 31. It has been experimentally found that premature aging of the lamp 10 can be reliably prevented with this measure, the effect on it should be based on the fact that the positive potential of the surroundings of the lamp 10 keeps the ions occurring in the lamp away from the lamp vessel and presses them into the plasma.

Unter der Annahme, daß das Teil 31 bereits mit einer Gerätemasse oder beispielsweise einer Betriebserde verbunden ist, mit der auch ein Pol 22, 24 der Quelle 21 verbunden ist, kann das Teil 31 nicht mit dem ersten Anschluß 27 am Ausgang 20 des Spannungswandlers 19 verbunden werden. Für diesen Fall ist die in Figur 2 gezeigte Ausgestaltung des Spannungswandlers 19 besonders vorteilhaft geeignet. Ein Pol 22, 24 der Quelle 21, im Beispiel der negative Pol 24, ist mit der elektrischen Gerätemasse 33 verbunden, die auch mit dem Teil 31 in Verbindung steht. Der Spannungswandler 19 ist als Invers-Wandler realisiert, bei dem die Polarität einer Eingangsspannung in eine umgekehrte Polarität am Ausgang 20 des Wandlers 19 umgesetzt wird. Auch hier wird bezüglich der Funktionsweise des Wandlers 19 auf die bereits zitierte Textstelle verwiesen. Die in Figur 2 gezeigte Verbindung zwischen dem Teil 31 und dem zweiten Anschluß 28 kann bei der Realisierung bereits gegeben sein, ohne daß es einer zusätzlichen Verbindung bedarf. Dieser Fall ist insbesondere dann gegeben, wenn das Teil 31 eine Lampenfassung, eine Leuchte oder wenigstens ein anderes, mit der elektrischen Gerätemasse 33 verbundenes Teil 31 ist.Assuming that part 31 is already connected to a device ground or, for example, an operating earth to which a pole 22, 24 of source 21 is also connected, part 31 cannot be connected to first connection 27 at output 20 of voltage converter 19 become. In this case, the configuration of the voltage converter 19 shown in FIG. 2 is particularly advantageously suitable. A pole 22, 24 of the source 21, in the example the negative pole 24, is connected to the electrical device ground 33, which is also connected to the part 31. The voltage converter 19 is implemented as an inverse converter, in which the polarity of an input voltage is converted into a reverse polarity at the output 20 of the converter 19. Here too, reference is made to the text passage already cited with regard to the functioning of the converter 19. The connection shown in FIG. 2 between the part 31 and the second connection 28 can already be provided during the implementation without the need for an additional connection. This is particularly the case if the part 31 is a lamp holder, a lamp or at least another part 31 connected to the electrical device mass 33.

Die in Figur 3 gezeigte Ausgestaltung des Spannungwandlers 19 weist den Vorteil einer Potentialtrennung zwischen der Quelle 21 und dem Ausgang 20 des Wandlers 19 auf. Dieser Vorteil ermöglicht der Trenntransformator 34. In Figur 3 ist als Beispiel eine Sperrwandler-Schaltung gezeigt. Der besondere Vorteil der transformatorischen Potentialtrennung liegt darin, daß das Teil 31, unabhängig davon, ob es mit der elektrischen Gerätemasse 33 oder einer Betriebserde verbunden ist, stets in einfacher Weise mit dem Anschluß 27, 28 am Ausgang 20 des Spannungswandlers 19 verbindbar ist, der das positive Potential in Bezug auf den anderen Anschluß 27, 28 aufweist.The configuration of the voltage converter 19 shown in FIG. 3 has the advantage of potential isolation between the source 21 and the output 20 of the converter 19. This advantage is made possible by the isolating transformer 34. A flyback converter circuit is shown as an example in FIG. The particular advantage of the transformer isolation is that the part 31, regardless of whether it is connected to the electrical device ground 33 or an operating earth, can always be connected in a simple manner to the connection 27, 28 at the output 20 of the voltage converter 19, which has the positive potential with respect to the other terminal 27, 28.

Claims (9)

  1. Device for operating a gas-discharge lamp (10), having a voltage converter (19) which converts a DC voltage from a power source into a predetermined output voltage, having a bridge circuit (12) which is connected to the output of the converter and in whose bridge diagonal the lamp is arranged, and having at least one part (31) which is arranged adjacent to the lamp, can carry an electrical potential and is arranged in such a manner that an electrical field can occur between the lamp and the part, characterized in that the part (31) is connected to that connection (27, 28) at the output (20) of the voltage converter (19) at which the positive potential occurs with respect to the other connection (27, 28).
  2. Device according to Claim 1, characterized in that the voltage converter (19) is an invertor, the negative pole (24) of the source (21) being connected to the part (31).
  3. Device according to Claim 2, characterized in that the invertor (19) contains a voltage converter switching means (25) which is connected to the positive pole (22) of the source (21), and a coil (23) which is connected to the negative pole (24) of the source (21), a diode (26) being connected to a connection of the switching means (25) to the coil (23), the anode of which diode (26) is connected to the first connection (27) at the output (20) of the voltage converter (19) at which a negative potential occurs with respect to the potential at the second connection (28).
  4. Device according to Claim 1, characterized in that the voltage converter (19) contains an isolating transformer (34).
  5. Device according to Claim 4, characterized in that the voltage converter (19) is implemented as an isolating converter.
  6. Device according to one of Claims 2 to 5, characterized in that the negative pole (24) of the source (21) is connected to an electrical equipment earth (33) to which the part (31) is connected.
  7. Device according to one of Claims 2 to 6, characterized in that a battery is provided as the source (21).
  8. Device according to one of Claims 1 to 7, characterized by the use of the device in a motor vehicle, in which the gas-discharge lamp (10) is arranged in at least one headlamp.
  9. Device according to Claim 8, characterized in that the negative pole (24) of the source (21) is electrically conductively connected to the vehicle bodywork.
EP92923352A 1991-12-18 1992-11-13 Device for operating a gas-discharge lamp Expired - Lifetime EP0572585B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE4141804 1991-12-18
DE4141804A DE4141804C1 (en) 1991-12-18 1991-12-18
PCT/DE1992/000946 WO1993012630A1 (en) 1991-12-18 1992-11-13 Device for operating a gas-discharge lamp

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EP0572585A1 EP0572585A1 (en) 1993-12-08
EP0572585B1 true EP0572585B1 (en) 1996-03-06

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EP (1) EP0572585B1 (en)
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DE (2) DE4141804C1 (en)
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WO (1) WO1993012630A1 (en)

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Publication number Priority date Publication date Assignee Title
DE4224996A1 (en) * 1992-07-29 1994-02-03 Hella Kg Hueck & Co Ballast for operating high-pressure gas discharge lamps with low-frequency, rectangular voltage in motor vehicles
DE4342590A1 (en) * 1993-12-14 1995-06-22 Bosch Gmbh Robert Clocked power supply
IT1268065B1 (en) * 1994-05-24 1997-02-20 Marelli Autronica POWER SUPPLY CIRCUIT, PARTICULARLY FOR VEHICLES.
US5583398A (en) * 1994-09-15 1996-12-10 Magnetek, Inc. Powerfactor correcting flyback arrangement having a resonant capacitor element connected across the switching element
US5955846A (en) * 1995-03-15 1999-09-21 Matsushita Electric Industrial Co., Ltd. Discharge lamp lighting device and a method for lighting a discharge lamp
EP0784912B1 (en) 1995-07-05 2001-10-31 Koninklijke Philips Electronics N.V. Circuit arrangement
JP3759996B2 (en) * 1996-01-08 2006-03-29 株式会社小糸製作所 Discharge lamp lighting circuit
JPH09266080A (en) * 1996-03-29 1997-10-07 Matsushita Electric Works Ltd Light source lighting device
DE19646861C1 (en) * 1996-11-13 1998-04-16 Bosch Gmbh Robert Device for operating a gas discharge lamp
US6031740A (en) * 1998-07-03 2000-02-29 Endress + Hauser Flowtec Ag Method of regulating the coil current of electromagnetic flow sensors
JP2003017283A (en) * 2001-06-29 2003-01-17 Ushio Inc Light source device
US6731075B2 (en) 2001-11-02 2004-05-04 Ampr Llc Method and apparatus for lighting a discharge lamp

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Publication number Priority date Publication date Assignee Title
US3909666A (en) * 1973-12-26 1975-09-30 Stanley N Tenen Ballast circuit for gaseous discharge lamps
FR2416617A1 (en) * 1978-02-07 1979-08-31 Signaux Entr Electriques CONVERTER FOR THE POWER SUPPLY OF DISCHARGE LAMPS, AND MORE GENERALLY OF ARC LAMPS, AND ITS APPLICATION TO PROJECTORS FOR SUCH LAMPS
US4200823A (en) * 1978-03-15 1980-04-29 Safety Products Strobe lamp warning apparatus
CA1060946A (en) * 1978-04-26 1979-08-21 Hydro-Quebec Stroboscopie beacons fed by a capacitive source___
NL8800015A (en) * 1988-01-06 1989-08-01 Philips Nv ELECTRICAL DEVICE FOR IGNITION AND POWERING A GAS DISCHARGE LAMP.
DE69114974T2 (en) * 1990-09-07 1996-04-11 Matsushita Electric Ind Co Ltd Lighting device with discharge lamp.

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ES2085047T3 (en) 1996-05-16
WO1993012630A1 (en) 1993-06-24
DE4141804C1 (en) 1993-02-25
JPH06505594A (en) 1994-06-23
EP0572585A1 (en) 1993-12-08
US5397965A (en) 1995-03-14
DE59205609D1 (en) 1996-04-11

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