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DE19717309A1 - Fluorescent lamp dimming circuit - Google Patents

Fluorescent lamp dimming circuit

Info

Publication number
DE19717309A1
DE19717309A1 DE1997117309 DE19717309A DE19717309A1 DE 19717309 A1 DE19717309 A1 DE 19717309A1 DE 1997117309 DE1997117309 DE 1997117309 DE 19717309 A DE19717309 A DE 19717309A DE 19717309 A1 DE19717309 A1 DE 19717309A1
Authority
DE
Germany
Prior art keywords
push
fluorescent lamp
transformer
comparator
pull converter
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
DE1997117309
Other languages
German (de)
Inventor
Berthold Birk
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.)
Siemens AG
Original Assignee
Mannesmann VDO AG
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 Mannesmann VDO AG filed Critical Mannesmann VDO AG
Priority to DE1997117309 priority Critical patent/DE19717309A1/en
Priority to JP54500398A priority patent/JP4116092B2/en
Priority to US09/402,619 priority patent/US6351080B1/en
Priority to DE59812414T priority patent/DE59812414D1/en
Priority to PCT/EP1998/002290 priority patent/WO1998048597A1/en
Priority to EP98924143A priority patent/EP0978221B1/en
Publication of DE19717309A1 publication Critical patent/DE19717309A1/en
Ceased legal-status Critical Current

Links

Classifications

    • 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
    • H02M7/00—Conversion of AC power input into DC power output; Conversion of DC power input into AC power output
    • H02M7/42—Conversion of DC power input into AC power output without possibility of reversal
    • H02M7/44—Conversion of DC power input into AC power output without possibility of reversal by static converters
    • H02M7/48—Conversion of DC power input into AC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/53—Conversion of DC power input into AC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M7/537—Conversion of DC power input into AC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters
    • H02M7/538—Conversion of DC power input into AC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a push-pull configuration
    • H02M7/53803—Conversion of DC power input into AC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a push-pull configuration with automatic control of output voltage or current
    • H02M7/53806—Conversion of DC power input into AC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a push-pull configuration with automatic control of output voltage or current in a push-pull configuration of the parallel type
    • 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
    • H05B41/2821—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 by means of a single-switch converter or a parallel push-pull converter in the final stage
    • H05B41/2824—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 by means of a single-switch converter or a parallel push-pull converter in the final stage using control circuits for the switching element
    • 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
    • H05B41/36—Controlling
    • H05B41/38—Controlling the intensity of light
    • H05B41/39—Controlling the intensity of light continuously
    • H05B41/392—Controlling the intensity of light continuously using semiconductor devices, e.g. thyristor

Landscapes

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

Abstract

The dimming circuit switches the operating frequency for the fluorescent lamp (KL) on and off at a dimming frequency with a variable pulse width, the dimming frequency being less than the operating frequency. The simultaneous adjustment of the operating voltage for the fluorescent lamp is provided by on-off switching of the supply voltage at a third frequency with a variable pulse width, the third frequency being greater than the operating frequency.

Description

Die Erfindung betrifft einen Gegentaktwandler mit einer überlagerten Stromrege­ lung, bestehend aus zwei Leistungsschaltern, welche jeweils im Primärkreis eines Transformators angeordnet sind und im Gegentakt von einer Steuerlogik ansteu­ erbar sind.The invention relates to a push-pull converter with a superimposed current rain tion, consisting of two circuit breakers, each in the primary circuit Transformers are arranged and driven by a control logic in push-pull are noticeable.

Bei diesen bekannten Gegentaktwandlern befindet sich zwischen den Leistungs­ schaltern und Masse üblicherweise eine Stromquelle zur Strombegrenzung. Diese Strombegrenzung ist notwendig, damit der Transformator nicht in die Sättigung gerät. Zu diesem Zweck ist es üblich, eine Stromregelung des Gegentaktwandlers durch zusätzliche Ansteuerschaltungen zu realisieren, was einen zusätzlichen Bauteileaufwand zur Folge hat.In these known push-pull converters is between the power switches and ground usually a current source for current limitation. This Current limitation is necessary so that the transformer does not saturate device. For this purpose, it is common to control the current of the push-pull converter to realize by additional control circuits, which is an additional Component effort results.

Der Erfindung liegt somit die Aufgabe zugrunde, einen Gegentaktwandler anzu­ geben, der die genannten Nachteile umgeht.The invention is therefore based on the object of starting a push-pull converter give who avoids the disadvantages mentioned.

Erfindungsgemäß wird die Aufgabe dadurch gelöst, daß durch eine überlagerte Taktung der Leistungsschalter eine Stromregelung realisiert wird.According to the invention the object is achieved in that a superimposed Clocking the circuit breaker a current control is realized.

Der Vorteil der Erfindung besteht darin, daß der Gegentaktwandler selbst neben der Gegentaktansteuerung einer Last gleichzeitig eine Stromregelung ausführt. Die sonst üblicherweise benötigte Stromquelle in Form eines Leistungstransistors mit zugehöriger Ansteuerung entfällt. The advantage of the invention is that the push-pull converter itself alongside the push-pull control of a load simultaneously executes a current control. The current source usually required in the form of a power transistor with associated control is omitted.  

Vorteilhafterweise ist zwischen den Leistungsschaltern und Masse ein Shuntwi­ derstand angeordnet, dessen Spannungsabfall zur Stromregelung verwendet wird.A shuntwi is advantageously between the circuit breakers and ground arranged the voltage drop used for current control becomes.

Dabei ist es besonders vorteilhaft, wenn der Spannungsabfall über einen Kompa­ rator an die Steuerlogik geführt wird, wobei der Spannungsabfall an einem ersten Eingang des Komparators an liegt, an dessen zweitem Eingang eine Referenz­ spannung anliegt.It is particularly advantageous if the voltage drop across a compa rator to the control logic, the voltage drop on a first Input of the comparator is present, at the second input a reference voltage is present.

Diese Anordnung erlaubt die überlagerte Taktung der Leistungsschalter durch die Steuerlogik.This arrangement allows the superimposed timing of the circuit breakers through the Control logic.

In einer Ausgestaltung ist jeder Leistungsschalter als MOSFET-Transistor aus­ gebildet, deren Drain mit dem Primärkreis des Transformators und deren Gate mit der Steuerlogik verbunden ist, wobei die Source beider Transistoren sowohl mit dem Shuntwiderstand als auch mit dem Komparator verbunden sind.In one configuration, each power switch is made as a MOSFET transistor formed, the drain with the primary circuit of the transformer and the gate with the control logic is connected, the source of both transistors with both the shunt resistor and the comparator.

Die Funktion der sonst üblichen Stromquelle wird durch die MOSFET-Transistoren ausgeführt.The function of the usual current source is through the MOSFET transistors executed.

Ein solcher Gegentaktwandler eignet sich für die Ansteuerung von Leucht­ stofflampen, die im Sekundärkreis des Transformators angeordnet sind.Such a push-pull converter is suitable for driving lights fabric lamps, which are arranged in the secondary circuit of the transformer.

Die Erfindung läßt zahlreiche Ausführungsformen zu. Eine davon soll anhand der in der Zeichnung dargestellten Figur näher erläutert werden.The invention permits numerous embodiments. One of them should be based on the are illustrated in the drawing.

Es zeigt:It shows:

Fig. 1 Schaltungsanordnung zur Ansteuerung einer Kaltkathodenleucht­ stofflampe, Fig. 1 circuit arrangement for driving a cold cathode fluorescent lamp,

Fig. 2a, b Zeitdiagramme zur Strombegrenzung der Kaltkathodenleuchtstoff­ lampe, FIG. 2a, b are timing diagrams for limiting the current of the cold cathode fluorescent lamp,

Fig. 3a, b Zeitdiagramme zur Ansteuerung der Kaltkathodenleuchtstofflampe. Fig. 3a, b are timing charts for driving the cold-cathode fluorescent lamp.

Fig. 1 zeigt eine Kaltkathodenleuchtstofflampe L, die im Sekundärkreis eines Transformators Tr angeordnet ist. Die Leuchtstofflampe L ist über einen Hoch­ spannungskondensator Cv mit dem Sekundärkreis des Transformators Tr ver­ bunden. Der Transformator Tr wird in seinem Primärkreis von zwei im Gegentakt schaltenden MOSFET-Transistoren T1 und T2 bestromt, welche von einer Steuer­ logik SL angesteuert werden, wobei der Primärkreis des Transformators Tr gleich­ zeitig mit der Betriebsspannung UB verbunden ist. Dabei ist jedes Gate G der Transistoren T1, T2 mit der Steuerlogik SL verbunden. Der Drain D jedes Tran­ sistors T1, T2 führt an die Primärwicklung des Transformators Tr, wobei die Sour­ ces S der MOSFET-Transistoren T1, T2 gemeinsam an einen Shuntwiderstand R1 führen, der an Masse liegt. Fig. 1 shows a cold cathode fluorescent lamp L, which is arranged in the secondary circuit of a transformer Tr. The fluorescent lamp L is connected via a high-voltage capacitor Cv to the secondary circuit of the transformer Tr. The transformer Tr is energized in its primary circuit by two push-pull switching MOSFET transistors T1 and T2, which are controlled by a control logic SL, the primary circuit of the transformer Tr being connected to the operating voltage U B at the same time. Each gate G of the transistors T1, T2 is connected to the control logic SL. The drain D of each transistor T1, T2 leads to the primary winding of the transformer Tr, the sources S of the MOSFET transistors T1, T2 leading together to a shunt resistor R1 which is connected to ground.

Die Steuerlogik SL verarbeitet als Eingangssignal einen Spannungsabfall über dem Shuntwiderstand R1. Der Spannungsabfall wird dem invertierenden Eingang eines Komparators K zugeführt, an dessen nichtinvertierendem Eingang eine Re­ ferenzspannung UREF mit konstantem Wert anliegt. Der Ausgang des Komparators K ist mit der Steuerlogik SL verbunden.The control logic SL processes a voltage drop across the shunt resistor R1 as an input signal. The voltage drop is fed to the inverting input of a comparator K, at the non-inverting input of which a reference voltage U REF with a constant value is applied. The output of the comparator K is connected to the control logic SL.

In Fig. 2a wird die Ansteuerung des MOSFET-Transistors T2 im Zusammenhang mit der Strombegrenzung dargestellt.In Fig. 2a, the control of the MOSFET transistor T2 is shown in connection with the current limitation.

Die Steuerlogik SL steuert den MOSFET-Transistor T2 impulsförmig an (Fig. 2a, Signal 1). Der durch den MOSFET-Transistor T2 fließende Strom wird als Span­ nungsabfall über dem Shuntwiderstand R1 gemessen und durch den Komparator K ausgewertet, der je nachdem, ob die gemessene Spannung den Referenzwert überschreitet oder nicht ein Low- oder High-Signal abgibt. (Fig. 2a, Signal 2). Das Ausgangssignal des Komparators K wird in der Steuerlogik SL logisch mit dem Signal 1 verknüpft. Dies führt dazu, daß der MOSFET-Transistor T2 während der Ansteuerung durch die Steuerlogik im Takt des Ausgangssignals des Kompa­ rators K durchgesteuert oder gesperrt wird.The control logic SL drives the MOSFET transistor T2 in a pulsed manner ( FIG. 2a, signal 1 ). The current flowing through the MOSFET transistor T2 is measured as a voltage drop across the shunt resistor R1 and evaluated by the comparator K, which, depending on whether the measured voltage exceeds the reference value or does not emit a low or high signal. ( Fig. 2a, signal 2 ). The output signal of the comparator K is logically linked to the signal 1 in the control logic SL. This leads to the fact that the MOSFET transistor T2 is turned on or off during the activation by the control logic in time with the output signal of the comparator K.

Ist der Strom zu groß, wird der Transistor T2 somit abgeschaltet, was in Fig. 2a, Signal 3 und in Fig. 2b, Signal 2 zum Zeitpunkt 6 dargestellt ist. In Fig. 2 stellt das Signal 1 somit die Hüllkurve für das Signal 3 dar.If the current is too high, the transistor T2 is thus switched off, which is shown in FIG. 2a, signal 3 and in FIG. 2b, signal 2 at time 6 . In FIG. 2, signal 1 thus represents the envelope for signal 3 .

Für den MOSFET-Transistor T1 gilt dieselbe Verfahrensweise, wobei die beiden Transistoren T1 und T2 alternierend von der Steuerlogik SL angesteuert wird. Das in Fig. 2a, Signal 2 dargestellte Komparatorausgangssignal zeigt, daß die Aus­ wertung für beide Transistoren über den selben Shuntwiderstand R1 vorgenom­ men werden.The same procedure applies to the MOSFET transistor T1, the two transistors T1 and T2 being driven alternately by the control logic SL. The comparator output signal shown in Fig. 2a, signal 2 shows that the evaluation for both transistors over the same shunt resistor R1 are vorgenom men.

Aufgrund dieser Maßnahme läßt sich der sonst üblicherweise benötigte Stromreg­ ler mit Leistungstransistor und zugehöriger Ansteuerung einsparen.This measure makes it possible to use the current regulator normally required Save time with the power transistor and associated control.

Die Funktion der Ansteuerung der Kaltkathodenleuchtstofflampe L wird im folgen­ den unter Bezugnahme auf Fig. 3a und b erläutert. Dabei sind über der Zeit auf­ getragen
The function of driving the cold cathode fluorescent lamp L is explained in the following with reference to FIGS . 3a and b. Here are worn over time

Signal 1 Ansteuersignal am MOSFET-Transistor T1
Signal 2 Ansteuersignal am MOSFET-Transistor T2
Signal 3 Strom durch die Kaltkathodenleuchtstofflampe L
Signal 4 Spannung über der Kaltkathodenleuchtstofflampe L.Signal 1 control signal at the MOSFET transistor T1
Signal 2 control signal at the MOSFET transistor T2
Signal 3 current through the cold cathode fluorescent lamp L
Signal 4 voltage across the cold cathode fluorescent lamp L.

Die beiden MOSFET-Transistoren T1, T2 werden nacheinander jeweils mit einem Impuls 1 einmalig angesteuert. Dadurch wird der Schwingkreis, bestehend aus dem Transformator Tr, dem Hochspannungskondensator Cv und der Leucht­ stofflampe L angestoßen. Der Schwingkreis klingt nach einer e-Funktion ab (vergl. Signal 4, Punkt 2). Das Gas in der Kaltkathodenleuchtstofflampe L kann sich in dieser Zeit ionisieren und organisieren. Nach einer bestimmten Zeit nach dem erstmaligen Anstoßen des Schwingkreises, z. B. nach 80 µsec. werden die Tran­ sistoren T1, T2 kontinuierlich in der üblichen Weise wechselseitig angesteuert (Signal 1 und 2, Punkt 4). Die Kaltkathodenleuchtstofflampe L gibt ab diesem Zeitpunkt sofort Licht ab (wie Signal 4 in Punkt 3 zu entnehmen ist). Nach der gewünschten Anzahl von Ansteuerimpulsen werden die beiden MOSFET-Transistoren gleichzeitig angesteuert, wie aus Fig. 3b, Signal 1 und 2 zum Zeitpunkt 5 hervorgeht. Dem Schwingkreis Tr, Cv, L wird dadurch schlagartig die Energie entzogen und die Lichtabgabe der Kaltkathodenleuchtstofflampe bricht sofort ab. Bei Raumtemperatur wurde mit einer Kaltkathodenleuchtstofflampe mit einer Nennleuchtdichte von 16.000 cd/m2 ein flackerfreier Dimmbereich von ca. 10.000 : 1 erreicht. Dieses Verfahren hat den Vorteil, daß der flackerfreie Betrieb der Leuchtstofflam­ pe L nur durch die spezielle Ansteuerung der MOSFET-Transistoren T1, T2 er­ reicht wird. Auf umfangreiche Steuerschaltungen, wie sonst üblich, kann verzichtet werden.The two MOSFET transistors T1, T2 are each activated once with a pulse 1 . This triggers the resonant circuit, consisting of the transformer Tr, the high-voltage capacitor Cv and the fluorescent lamp L. The resonant circuit decays according to an e-function (see signal 4 , point 2 ). The gas in the cold cathode fluorescent lamp L can ionize and organize itself during this time. After a certain time after the resonance circuit has been started for the first time, e.g. B. after 80 microseconds. the transistors T1, T2 are driven alternately in the usual way (signal 1 and 2 , point 4 ). From this point in time, the cold cathode fluorescent lamp L emits light immediately (as can be seen from signal 4 in point 3 ). After the desired number of drive pulses, the two MOSFET transistors are driven simultaneously, as can be seen from FIG. 3b, signals 1 and 2 at time 5 . The energy is suddenly withdrawn from the resonant circuit Tr, Cv, L and the light emission from the cold cathode fluorescent lamp stops immediately. At room temperature, a flicker-free dimming range of approx. 10,000: 1 was achieved with a cold cathode fluorescent lamp with a nominal luminance of 16,000 cd / m 2 . This method has the advantage that the flicker-free operation of the fluorescent lamp L L is only achieved by the special control of the MOSFET transistors T1, T2. Comprehensive control circuits, as is usually the case, can be dispensed with.

Claims (5)

1. Gegentaktwandler mit überlagerter Stromregelung, bestehen aus zwei Lei­ stungsschaltern, welche jeweils im Primärkreis eines Transformators ange­ ordnet sind, und im Gegentakt von einer Steuerlogik ansteuerbar sind, da­ durch gekennzeichnet, daß durch eine überlagerte Taktung der Leistungs­ schalter eine Stromregelung realisiert wird.1. push-pull converter with superimposed current control, consist of two Lei stungsschalter, which are each arranged in the primary circuit of a transformer, and can be controlled in push-pull by a control logic, as characterized in that current control is realized by a superimposed timing of the power switch. 2. Gegentaktwandler nach Anspruch 1 dadurch gekennzeichnet, daß zwischen den Leistungsschaltern (T1, T2) und Masse ein Shuntwiderstand (R1) ange­ ordnet ist, dessen Spannungsabfall zur Stromregelung verwendet wird.2. push-pull converter according to claim 1, characterized in that between the circuit breakers (T1, T2) and ground a shunt resistor (R1) is arranged, whose voltage drop is used for current control. 3. Gegentaktwandler nach Anspruch 2, dadurch gekennzeichnet, daß der Spannungsabfall über einen Komparator (K) an die Steuerlogik (SL) geführt wird, wobei der Spannungsabfall an einen ersten Eingang des Komparators (K) an liegt, an dessen zweiten Eingang eine Referenzspannung geführt ist.3. push-pull converter according to claim 2, characterized in that the Voltage drop led to the control logic (SL) via a comparator (K) is, the voltage drop at a first input of the comparator (K) is present, at the second input of which a reference voltage is conducted. 4. Gegentaktwandler nach Anspruch 2 oder 3, dadurch gekennzeichnet, daß die Leistungsschalter (T1, T2) MOSFET-Transistoren sind, deren Drain (D) dem Primärkreis des Transformators (Tr) und deren Gate (G) mit der Steuer­ logik (SL) verbunden ist, wobei die Sources (S) beider Transistoren (T1, T2) sowohl mit dem Shuntwiderstand (R1) als auch mit dem Komparator (K) ver­ bunden sind.4. push-pull converter according to claim 2 or 3, characterized in that the power switches (T1, T2) are MOSFET transistors whose drain (D) the primary circuit of the transformer (Tr) and its gate (G) with the tax logic (SL) is connected, the sources (S) of both transistors (T1, T2) ver with both the shunt resistor (R1) and the comparator (K) are bound. 5. Gegentaktwandler nach einem der vorhergehenden Ansprüchen dadurch ge­ kennzeichnet, daß im Sekundärkreis des Transformators (T) über eine Im­ pedanz (Gv) eine Leuchtstofflampe (L) ansteuerbar ist.5. push-pull converter according to one of the preceding claims thereby ge indicates that in the secondary circuit of the transformer (T) via an Im pedanz (Gv) a fluorescent lamp (L) can be controlled.
DE1997117309 1997-04-24 1997-04-24 Fluorescent lamp dimming circuit Ceased DE19717309A1 (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
DE1997117309 DE19717309A1 (en) 1997-04-24 1997-04-24 Fluorescent lamp dimming circuit
JP54500398A JP4116092B2 (en) 1997-04-24 1998-04-17 Circuit arrangement for dimmable operation of a fluorescent lamp
US09/402,619 US6351080B1 (en) 1997-04-24 1998-04-17 Circuitry for dimming a fluorescent lamp
DE59812414T DE59812414D1 (en) 1997-04-24 1998-04-17 CIRCUIT ARRANGEMENT FOR DIMMABLE OPERATION OF A FLUORESCENT LAMP
PCT/EP1998/002290 WO1998048597A1 (en) 1997-04-24 1998-04-17 Circuitry for dimming a fluorescent lamp
EP98924143A EP0978221B1 (en) 1997-04-24 1998-04-17 Circuitry for dimming a fluorescent lamp

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE1997117309 DE19717309A1 (en) 1997-04-24 1997-04-24 Fluorescent lamp dimming circuit

Publications (1)

Publication Number Publication Date
DE19717309A1 true DE19717309A1 (en) 1998-11-05

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Application Number Title Priority Date Filing Date
DE1997117309 Ceased DE19717309A1 (en) 1997-04-24 1997-04-24 Fluorescent lamp dimming circuit

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DE (1) DE19717309A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE20303593U1 (en) * 2002-12-23 2004-05-06 Steca Batterieladesysteme und Präzisionselektronik GmbH Switching transformer, especially for use as electronic ballast for a direct current discharge bulb, has a control unit with two field effect transistors

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
DE-Z.: KLOSE, M.: "Gleichspannungswandler: 220 V aus dem Autoakku" in: "Funkschau" 21/1984, S. 81-85 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE20303593U1 (en) * 2002-12-23 2004-05-06 Steca Batterieladesysteme und Präzisionselektronik GmbH Switching transformer, especially for use as electronic ballast for a direct current discharge bulb, has a control unit with two field effect transistors

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Owner name: SIEMENS AG, 80333 MUENCHEN, DE

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