EP0406285A1 - Circuit arrangement for monitoring the duty cycle of a transistor - Google Patents

Circuit arrangement for monitoring the duty cycle of a transistor

Info

Publication number
EP0406285A1
EP0406285A1 EP19890903955 EP89903955A EP0406285A1 EP 0406285 A1 EP0406285 A1 EP 0406285A1 EP 19890903955 EP19890903955 EP 19890903955 EP 89903955 A EP89903955 A EP 89903955A EP 0406285 A1 EP0406285 A1 EP 0406285A1
Authority
EP
European Patent Office
Prior art keywords
transistor
capacitor
voltage
circuit
series
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.)
Withdrawn
Application number
EP19890903955
Other languages
German (de)
French (fr)
Inventor
Wolfgang Grabner
Otmar Bitsche
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Stylux Gesellschaft fur Lichtelektronik Mbh
Stylux Gesellschaft fur Lichtelektronik mbH
Original Assignee
Stylux Gesellschaft fur Lichtelektronik Mbh
Stylux Gesellschaft fur Lichtelektronik mbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Stylux Gesellschaft fur Lichtelektronik Mbh, Stylux Gesellschaft fur Lichtelektronik mbH filed Critical Stylux Gesellschaft fur Lichtelektronik Mbh
Publication of EP0406285A1 publication Critical patent/EP0406285A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
    • H05B41/14—Circuit arrangements
    • H05B41/26—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc
    • H05B41/28—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters
    • H05B41/282—Circuit arrangements in which the lamp is fed by power derived from dc by means of a converter, e.g. by high-voltage dc using static converters with semiconductor devices
    • H05B41/285—Arrangements for protecting lamps or circuits against abnormal operating conditions
    • H05B41/2851—Arrangements for protecting lamps or circuits against abnormal operating conditions for protecting the circuit against abnormal operating conditions
    • H05B41/2856—Arrangements for protecting lamps or circuits against abnormal operating conditions for protecting the circuit against abnormal operating conditions against internal abnormal circuit conditions
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/338—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only in a self-oscillating arrangement
    • H02M3/3385—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only in a self-oscillating arrangement with automatic control of output voltage or current
    • 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
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Definitions

  • the invention relates to a circuit arrangement for monitoring the duty cycle of a transistor.
  • the object of the invention is to provide a duty cycle monitoring circuit for a transistor, which is in connection with the Ar.
  • the invention is characterized in that a choke-capacitor series resonant circuit is connected to a direct voltage, which is preferably the mains voltage rectified via a bridge rectifier with a downstream capacitor, and parallel to the capacitor of this series resonant circuit, on the one hand, the collector-emitter path of the transistor to be monitored with an emitter resistor in series and the other one
  • Free-wheeling diode for the transistor is connected and that a drive circuit connected to the base of the transistor is provided, to which the voltage at the capacitor is applied at a second input and the voltage at the emitter resistor at a third input, and that the collector circuit is connected to a fourth input of the drive circuit.
  • Emitter path of a transistor is connected to zero potential, a capacitor being connected to the base of this transistor, to which a diode is connected, which is connected to the cathode at the junction of the inductor and capacitor in the series resonant circuit and that each at both terminals of the capacitor there is resistance to a voltage.
  • the choke-capacitor series resonant circuit can be operated perfectly in a wide supply voltage range, ie the transistor is parallel to the resonant circuit capacitor always synchronized with the resonant circuit.
  • the capacitance of the smoothing capacitor after the bridge rectifier can be small, as a result of which its size is reduced to a minimum.
  • the rectified voltage Ue of a bridge rectifier which is connected to the mains voltage on the primary side, reaches terminals 1, 2 in FIG.
  • the negative pole 2 of the voltage Ue is connected to the neutral potential 10.
  • the smoothing capacitor C 3 is connected to the voltage Ue and serves to minimize the ripple of this voltage Ue.
  • a series resonant circuit which is connected to the smoothed voltage Ue and consists of the two chokes L 1, L 2 and the capacitor C 1 is provided below.
  • One terminal of the capacitor C 1 is connected to the Nuiipotential 10.
  • a load that z. B. can be a gas discharge lamp, is arranged parallel to the series resonant circuit L 1, L 2, C 1.
  • a free-wheeling diode D and the collector-emitter path of a transistor T 1 with an emitter resistor R 3 are connected in parallel to the capacitor C 1.
  • the base of transistor T 1 is connected to input E 1 and the emitter to input E 3 of a control circuit AS.
  • a voltage proportional to the discharge current of the capacitor C 1 thus reaches the input E 3 when the transistor T 1 is switched on.
  • the control circuit AS also has an input E 2 at which the voltage Uc at the capacitor C 1 is present.
  • the input E 4 of the control circuit AS is connected to the collector of a transistor T 2, the emitter of which is connected to the neutral potential 10.
  • a capacitor C 2 is connected to the base of the transistor T 2 and is connected to the connection of the inductor L 2 to the capacitor C 1 via a diode D 1.
  • a resistor R 1, R 2 is connected to both connections of the capacitor C 2 and is connected to a supply voltage Vc which is substantially smaller than the voltage Ue.
  • the voltage Vc also reaches the control circuit AS.
  • the uppermost time diagram in FIG. 2 shows the voltage and current distribution on capacitor C 1 and the diagrams below show the voltage curves at points P 1, P 2 and P 3 marked in FIG. 1.
  • the transistor T 1 is synchronized with the series resonant circuit by monitoring the voltage Uc across the capacitor C 1 and the current Ic. At low voltages Ue Ic max is not reached and the transistor T 1 can no longer be synchronized with the series resonant circuit.
  • the circuit is used to operate the series resonant circuit in a wide voltage range [Ue ⁇ Vc (a few volts) up to 400V]. The resonant circuit can thus be operated with a practically unsaturated mains voltage and the capacitor C 3 can be dimensioned very small.
  • the circuit is particularly suitable as an add-on for electronic pre-devices for gas discharge lamps that have a series resonant circuit as the main resonant circuit.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Circuit Arrangements For Discharge Lamps (AREA)

Abstract

Un circuit oscillant (L2, C1) de réactance et de condensateur en série est connecté à une tension continue (Ue), par exemple la tension continue du réseau. Un transistor (T1) avec une résistance émettrice (R3) et une diode de roue libre (D) est connecté en parallèle au condensateur (C1) du circuit oscillant en série (L2, C1). La base du transistor (T1) est connectée à un circuit d'amorçage (AS) qui reçoit également la tension du condensateur (C1) et la tension de la résistance émettrice (R3). Un transistor supplémentaire (T2) est connecté à une entrée supplémentaire (E4) du circuit d'amorçage (AS). La base de ce transistor (T2) est connectée par un condensateur (C2) associé à une diode (D1) à la connexion entre la réactance (L2) et le condensateur (C1). Les deux raccordements du condensateur (C2) sont reliés chacun par une résistance (R1, R2) à une tension continue positive (Vc). Pendant son fonctionnement normal, le transistor (T1) est bloqué par le circuit d'amorçage (AS) lorsqu'un courant collecteur déterminé (Ic) est atteint. Si celui-ci n'est pas atteint, le transistor (T2) est activé et bloque le transistor (T1) après une durée déterminée. Une charge découplée peut être connectée par un transformateur (L1) au circuit en série (L2, C1).An oscillating circuit (L2, C1) of reactance and capacitor in series is connected to a direct voltage (Ue), for example the direct voltage of the network. A transistor (T1) with an emitting resistor (R3) and a freewheeling diode (D) is connected in parallel with the capacitor (C1) of the series oscillating circuit (L2, C1). The base of the transistor (T1) is connected to a starting circuit (AS) which also receives the voltage of the capacitor (C1) and the voltage of the emitting resistor (R3). An additional transistor (T2) is connected to an additional input (E4) of the starting circuit (AS). The base of this transistor (T2) is connected by a capacitor (C2) associated with a diode (D1) to the connection between the reactance (L2) and the capacitor (C1). The two connections of the capacitor (C2) are each connected by a resistor (R1, R2) to a positive direct voltage (Vc). During its normal operation, the transistor (T1) is blocked by the starting circuit (AS) when a determined collector current (Ic) is reached. If this is not reached, the transistor (T2) is activated and blocks the transistor (T1) after a determined period. A decoupled load can be connected by a transformer (L1) to the series circuit (L2, C1).

Description

Schaltungsanordnung zur Überwachung der Einschaltdauer eines TransistorsCircuit arrangement for monitoring the duty cycle of a transistor
Die Erfindung betrifft eine Schaitungsanordnung zur Überwachung der Einschaltdauer eines Transistors.The invention relates to a circuit arrangement for monitoring the duty cycle of a transistor.
Diesbezügliche Schaltungen für die verschiedensten Anwendungen sind hinlänglich bekannt.Circuits in this regard for a wide variety of applications are well known.
Die Aufgabe der Erfindung besteht darin, eine Einschaltdauer-Überwachungsschaltung für einen Transistor zu schaffen, die in Verbindung mit dessen Ar.steuerschaltung steht und auch auf diese einwirkt.The object of the invention is to provide a duty cycle monitoring circuit for a transistor, which is in connection with the Ar.steuerschaltung and also acts on this.
Um die Aufgabe zu lösen ist die Erfindung dadurch gekennzeichnet, daß ein Drossel-Kondensator-Serienschwingkreis an einer Gleichspannung liegt, die vorzugsweise die über einen Brücker.gleichrichter gleichgerichtete Netzspannung mit nachgeschaltetem Giättungskondensator ist, und parallel zum Kondensator dieses Serienschwingkreises einerseits die KollektorEmitter-Strecke des zu überwachenden Transistors mit einem Emitterwiderstand in Serie und andererseits eineIn order to achieve the object, the invention is characterized in that a choke-capacitor series resonant circuit is connected to a direct voltage, which is preferably the mains voltage rectified via a bridge rectifier with a downstream capacitor, and parallel to the capacitor of this series resonant circuit, on the one hand, the collector-emitter path of the transistor to be monitored with an emitter resistor in series and the other one
Freilaufdiode für den Transistor geschaltet ist und daß eine mit der Basis des Transistors verbundene Ansteuerschaltung vorgesehen ist, der an einem zweiten Eingang die Spannung am Kondensator und an einem dritten Eingang die Spannung am Emitterwiderstand angelegt ist und daß an einem vierten Eingang der Ansteuerschaitung die Kollektor-Emitter-Strecke eines Transistors gegen Nullpotential angeschlossen ist, wobei mit der Basis dieses Transistors ein Kondensator verbunden ist, dem eine Diode nachgeschaltet ist, die mit der Katode an den Verbindungspunkt von Drossel und Kondensator im Serienschwingkreis angeschlossen ist und daß an beiden Anschlüssen des Kondensators je ein Widerstand an einer Spannung liegt. Durch diese Schaltung kann der DrosselKondensator-Serienschwingkreis in einem weiten versorgungsspannungsbereich einwandfrei betrieben werden, d. h. der Transistor parallel zum Schwingkreiskondensator ist mit dem Schwingkreis immer synchronisiert. Außerdem kann die Kapazität des Glättungskondensators nach dem Brükkengleichrichter klein sein, wodurch sich dessen Baugröße auf ein Minimum reduziert.Free-wheeling diode for the transistor is connected and that a drive circuit connected to the base of the transistor is provided, to which the voltage at the capacitor is applied at a second input and the voltage at the emitter resistor at a third input, and that the collector circuit is connected to a fourth input of the drive circuit. Emitter path of a transistor is connected to zero potential, a capacitor being connected to the base of this transistor, to which a diode is connected, which is connected to the cathode at the junction of the inductor and capacitor in the series resonant circuit and that each at both terminals of the capacitor there is resistance to a voltage. With this circuit, the choke-capacitor series resonant circuit can be operated perfectly in a wide supply voltage range, ie the transistor is parallel to the resonant circuit capacitor always synchronized with the resonant circuit. In addition, the capacitance of the smoothing capacitor after the bridge rectifier can be small, as a result of which its size is reduced to a minimum.
An Hand des in Fig. 1 dargestellten Schaltbildes und der in Fig. 2 ersichtlichen Zeitdiagramme wird die Erfindung nun noch näher erläutert.The invention will now be explained in more detail with reference to the circuit diagram shown in FIG. 1 and the time diagrams shown in FIG. 2.
An die Klemmen 1, 2 in Fig. 1 gelangt die gleichgerichtete Spannung Ue eines Brückengleichrichters, der primärseitig an der Netzspannung liegt. Der negative Pol 2 der Spannung Ue ist mit Nuiipotential 10 verbunden. Der Glättungskondensator C 3 ist an die Spannung Ue gelegt und dient zur Minimierung der Weliigkeit dieser Spannung Ue. Nachfolgend ist ein Serienschwingkreis, der an der geglätteten Spannung Ue liegt, und aus den beiden Drosseln L 1, L 2 und dem Kondensator C 1 besteht, vorgesehen. Der eine Anschluß des Kondensators C 1 ist mit Nuiipotential 10 verbunden. Eine Last, die z. B. eine Gasentladungslampe sein kann, wird parallel zum Serienschwingkreis L 1, L 2, C 1 angeordnet. Dem Kondensator C 1 ist eine Freilaufdiode D und die KollektorEmitter-Strecke eines Transistors T 1 mit einem Emitterwiderstand R 3 parallel geschaltet. Die Basis des Transistors T 1 ist mit dem Eingang E 1 und der Emitter mit dem Eingang E 3 einer AnsteuerSchaltung AS verbunden. An den Eingang E 3 gelangt somit bei durchgeschaltetem Transistor T 1 eine dem Entladestrom des Kondensators C 1 proportionale Spannung. Die Ansteuerschaltung AS besitzt noch einen Eingang E 2 an dem die Spannung Uc am Kondensator C 1 ansteht. Der Eingang E 4 der Ansteuerschaltung AS ist mit dem Kollektor eines Transistors T 2 verbunden, dessen Ermitter an Nuiipotential 10 liegt. An der Basis des Transistors T 2 ist ein Kondensator C 2 angeschlossen, der über eine Diode D 1 an der Verbindung der Drossel L 2 mit dem Kondensator C 1 liegt. Dabei ist die Anode der Diode D 1 mit dem Kondensator C 2 verbunden. An beiden Anschlüssen des Kondensators C 2 ist ein Widerstand R 1, R 2 angeschlossen, der an einer Versorgungspannung Vc liegt, die wesentlich kleiner als die Spannung Ue ist. Auch an die Ansteuerschaltung AS gelangt die Spannung Vc.The rectified voltage Ue of a bridge rectifier, which is connected to the mains voltage on the primary side, reaches terminals 1, 2 in FIG. The negative pole 2 of the voltage Ue is connected to the neutral potential 10. The smoothing capacitor C 3 is connected to the voltage Ue and serves to minimize the ripple of this voltage Ue. A series resonant circuit which is connected to the smoothed voltage Ue and consists of the two chokes L 1, L 2 and the capacitor C 1 is provided below. One terminal of the capacitor C 1 is connected to the Nuiipotential 10. A load that z. B. can be a gas discharge lamp, is arranged parallel to the series resonant circuit L 1, L 2, C 1. A free-wheeling diode D and the collector-emitter path of a transistor T 1 with an emitter resistor R 3 are connected in parallel to the capacitor C 1. The base of transistor T 1 is connected to input E 1 and the emitter to input E 3 of a control circuit AS. A voltage proportional to the discharge current of the capacitor C 1 thus reaches the input E 3 when the transistor T 1 is switched on. The control circuit AS also has an input E 2 at which the voltage Uc at the capacitor C 1 is present. The input E 4 of the control circuit AS is connected to the collector of a transistor T 2, the emitter of which is connected to the neutral potential 10. A capacitor C 2 is connected to the base of the transistor T 2 and is connected to the connection of the inductor L 2 to the capacitor C 1 via a diode D 1. Here is the Anode of diode D 1 connected to capacitor C 2. A resistor R 1, R 2 is connected to both connections of the capacitor C 2 and is connected to a supply voltage Vc which is substantially smaller than the voltage Ue. The voltage Vc also reaches the control circuit AS.
Das oberste Zeitdiagramm in Fig. 2 zeigt den Spannungsund Stromveriauf »am Kondensator C 1 und die darunter liegenden Diagramme zeigen die Spannungsverläufe an den in Fig. 1 markierten Punkten P 1, P 2, und P 3.The uppermost time diagram in FIG. 2 shows the voltage and current distribution on capacitor C 1 and the diagrams below show the voltage curves at points P 1, P 2 and P 3 marked in FIG. 1.
Die Synchronisation des Transistors T 1 mit dem Serienschwingkreis erfolgt durch Überwachung der Spannung Uc am Kondensator C 1 und des Stromes Ic. Bei niedrigen Spannungen Ue wird Ic max nicht erreicht, und der Transistor T 1 kann mit dem Serienschwingkreis nicht mehr synchronisiert werden. Um den Serienschwingkreis jedoch in einem weiten Spannungsbereich [Ue ~ Vc (einige Volt) bis 400V] betreiben zu können, dient die Schaltung. Damit kann der Schwingkreis mit praktisch ungegelätteter Netzspannung betrieben werden und der Kondensator C 3 kann sehr klein dimensioniert werden.The transistor T 1 is synchronized with the series resonant circuit by monitoring the voltage Uc across the capacitor C 1 and the current Ic. At low voltages Ue Ic max is not reached and the transistor T 1 can no longer be synchronized with the series resonant circuit. The circuit is used to operate the series resonant circuit in a wide voltage range [Ue ~ Vc (a few volts) up to 400V]. The resonant circuit can thus be operated with a practically unsaturated mains voltage and the capacitor C 3 can be dimensioned very small.
Die Diode D 1, die Widerstände R 1, R 2, der Kondensator C 2 und der Transistor T 2, bilden gemeinsam mit dem Schwingkreis eine astabile Kippstufe. Dessen Funktion für I<I max zeigt die Fig. 2. An Hand dieser wird noch die Funktionsweise der Schaltung erklärt.The diode D 1, the resistors R 1, R 2, the capacitor C 2 and the transistor T 2, together with the resonant circuit, form an astable multivibrator. Its function for I <I max is shown in FIG. 2. The functioning of the circuit is explained on the basis of this.
Sinkt Uc auf 0 Volt, sinkt auch das Potential an P 1 von Vc auf 0 Volt. Dadurch wird der Kondensator C 2 umgepolt und das Potential P 2 sinkt von +0,7 Volt auf -Vc und steigt anschließend wieder linear auf 0,7 Volt an, da der Kondensator C 2 über den Widerstand R 2 aufgeladen wird. Bei Erreichen der Schaltschwelle von 0,7 Volt von Transistor T 2, schaltet dieser durch und Transistor T 1 wird über die Ansteuerschaitung AS abgeschaltet. Durch entsprechende Dimensionierung von Widerstand R 2 und Kondensator C 2 kann die maximale Einschaltdauer von T 1 auf jeden beliebigen Wert eingestellt werden. Bei höheren Spannungen Ue, steigt der Strom Ic entsprechend schneller an und erreicht den Wert Ic max bevor Kondensator C 2 auf 0,7 Volt aufgeladen ist. Damit kann die erfindungsgemäße Schaltung die Ansteuerschaltung AS bei hohen Eingangsspannungen nicht beeinflussen.If Uc drops to 0 volts, the potential at P 1 drops from Vc to 0 volts. As a result, the capacitor C 2 is reversed and the potential P 2 drops from +0.7 volts to -Vc and then rises again linearly to 0.7 volts because the capacitor C 2 is charged via the resistor R 2. When the switching threshold of 0.7 volts of transistor T 2 is reached, this switches through and transistor T 1 becomes switched off via the control circuit AS. By appropriately dimensioning resistor R 2 and capacitor C 2, the maximum duty cycle of T 1 can be set to any value. At higher voltages Ue, the current Ic increases correspondingly faster and reaches the value Ic max before capacitor C 2 is charged to 0.7 volts. Thus the circuit according to the invention cannot influence the control circuit AS at high input voltages.
Die Schaltung eignet sich besonders als Zusatz für elektronische Vorschaitgeräte für Gasentladungslampen die einen Serienschwingkreis als Hauptschwingkreis aufweisen. The circuit is particularly suitable as an add-on for electronic pre-devices for gas discharge lamps that have a series resonant circuit as the main resonant circuit.

Claims

PATENTANSPRUCHPATENT CLAIM
Schaltungsanordnung zur Überwachung der Einschaltdauer eines Transistors dadurch gekennzeichnet, daß ein Drossel-Kondensator-Serienschwingkrels (L1, L2 , C1), an einer Gleichspannung liegt, die vorzugsweise die über einen Brückengleichrichter gleichgerichtete Netzspannung mit nachgeschaltetem Glättungskondensator (C3) ist, und parallel zum Kondensator (C 1) dieses Serienschwingkreises (L 1, L 2, C 1) einerseits die Kollektor-Emitter-Strecke des zu überwachenden Transistors (T 1) mit einem Emitterwiderstand (R 3) in Serie und andererseits eine Freilaufdiode (D) für den Transistor (T 1) geschaltet ist und daß eine mit der Basis des Transistors (T 1) verbundene Ansteuerschaltung (AS) vorgesehen ist, der an einem zweiten Eingang (E 2) die Spannung am Kondensator (C 1) und an einem dritten Eingang (E 3) die Spannung am Emitterwiderstand (R 3) angelegt ist und daß an einem vierten Eingang (E 4) der Ansteuerschaitung (AS) die Koliektor-Emitter-Strecke eines Transistors (T 2) gegen Nullpotential (10) angeschlossen ist, wobei mit der Basis dieses Transistors (T 2) ein Kondensator (C 2) verbunden ist, dem eine Diode (D 1) nachgeschaltet ist, die mit der Katode an den Verbindungspunkt von Drossel (L 2) und Kondensator (C 1) im Serienschwingkreis (L1, L2 , C 1) angeschlossen ist und daß an beiden Anschlüssen des Kondensators (C 2) je ein Widerstand (R 1, R 2) an einer Spannung (Vc) liegt. Circuit arrangement for monitoring the duty cycle of a transistor, characterized in that a choke capacitor series oscillating circuit (L1, L2, C1) is connected to a DC voltage, which is preferably the rectified mains voltage via a bridge rectifier with a downstream smoothing capacitor (C3), and in parallel with the capacitor (C 1) of this series resonant circuit (L 1, L 2, C 1) on the one hand the collector-emitter path of the transistor (T 1) to be monitored with an emitter resistor (R 3) in series and on the other hand a free-wheeling diode (D) for the transistor (T 1) is connected and that a drive circuit (AS) connected to the base of the transistor (T 1) is provided, which has the voltage at the capacitor (C 1) at a second input (E 2) and at a third input (E 3) the voltage is applied to the emitter resistor (R 3) and that at a fourth input (E 4) of the control circuit (AS) the coliector-emitter path of a transistor (T 2) against Nu llpotential (10) is connected, with the base of this transistor (T 2) a capacitor (C 2) is connected, which is followed by a diode (D 1) which is connected to the cathode at the connection point of the choke (L 2) and Capacitor (C 1) is connected in the series resonant circuit (L1, L2, C 1) and that a resistor (R 1, R 2) is connected to a voltage (Vc) at both connections of the capacitor (C 2).
EP19890903955 1988-03-18 1989-03-07 Circuit arrangement for monitoring the duty cycle of a transistor Withdrawn EP0406285A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AT740/88 1988-03-18
AT74088 1988-03-18

Publications (1)

Publication Number Publication Date
EP0406285A1 true EP0406285A1 (en) 1991-01-09

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP19890903955 Withdrawn EP0406285A1 (en) 1988-03-18 1989-03-07 Circuit arrangement for monitoring the duty cycle of a transistor

Country Status (2)

Country Link
EP (1) EP0406285A1 (en)
WO (1) WO1989008971A1 (en)

Families Citing this family (4)

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Publication number Priority date Publication date Assignee Title
NO913368D0 (en) * 1991-08-27 1991-08-27 Julius Hartai FREQUENCY MODULATED DRIVER WITH PARALLEL RESONANCE.
FR2693618B1 (en) * 1992-07-07 1994-09-23 Aupem Apparatus for supplying high frequency high voltage to a gas discharge tube.
US5313145A (en) * 1992-08-31 1994-05-17 Francis Jr Ralph M Power supply for a gas discharge device
EP0620700A1 (en) * 1993-04-15 1994-10-19 Heinrich Korte Electronic ballast

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Publication number Priority date Publication date Assignee Title
GB2087675B (en) * 1980-10-07 1984-03-28 Texas Instruments Ltd Electrical inverter
GB2120870B (en) * 1982-05-12 1986-03-12 Hsiung Chiou Eric De Electronic ballast for gas discharge lamps and fluorescent lamps
DE3507172A1 (en) * 1985-03-01 1986-09-04 Deutsche Thomson-Brandt Gmbh, 7730 Villingen-Schwenningen VOLTAGE CONVERTER

Non-Patent Citations (1)

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Title
See references of WO8908971A1 *

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Publication number Publication date
WO1989008971A1 (en) 1989-09-21

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