EP0075774A2 - Electronic ballast for at least one fluorescent lamp - Google Patents

Electronic ballast for at least one fluorescent lamp Download PDF

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Publication number
EP0075774A2
EP0075774A2 EP82108398A EP82108398A EP0075774A2 EP 0075774 A2 EP0075774 A2 EP 0075774A2 EP 82108398 A EP82108398 A EP 82108398A EP 82108398 A EP82108398 A EP 82108398A EP 0075774 A2 EP0075774 A2 EP 0075774A2
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EP
European Patent Office
Prior art keywords
capacitor
electronic
resonant circuit
series resonant
coil
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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.)
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EP82108398A
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German (de)
French (fr)
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EP0075774A3 (en
Inventor
Fred Dr.-Ing. Hasemann
Ferdinand Dipl.-Ing. Mertens
Norbert Dipl.-Ing. Wittig
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Trilux GmbH and Co KG
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Trilux Lenze GmbH and Co KG
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Publication of EP0075774A2 publication Critical patent/EP0075774A2/en
Publication of EP0075774A3 publication Critical patent/EP0075774A3/en
Withdrawn legal-status Critical Current

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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
    • H05B41/02—Details
    • H05B41/04—Starting switches
    • H05B41/042—Starting switches using semiconductor devices
    • H05B41/044—Starting switches using semiconductor devices for lamp provided with pre-heating electrodes
    • H05B41/046—Starting switches using semiconductor devices for lamp provided with pre-heating electrodes using controlled semiconductor devices
    • 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

Definitions

  • the invention relates to an electronic ballast for at least one fluorescent lamp, with a series resonant circuit containing an inductor and a capacitor, the capacitance or inductance of which the fluorescent lamp can be connected in parallel, and with an electronic switching device connected to a direct voltage source for phase-appropriate periodic feeding of a current into the series resonant circuit.
  • the previously common ballasts for fluorescent lamps have a bimetallic element which interrupts the flow of current through a coil when heated in order to generate a high voltage on the coil for igniting the fluorescent lamp.
  • the individual ignition attempts are slow at long intervals, which results in flickering and delayed ignition of the fluorescent lamp.
  • Another disadvantage is the high energy consumption of the ballast due to the coil connected in series with the fluorescent lamp, which coil is constantly supplied with current during operation of the fluorescent lamp.
  • ballasts which contain a series resonant circuit consisting of an inductor and a capacitor, the resonance frequency of which is above 20 kHz.
  • the fluorescent lamp is connected in parallel to the capacitor of the series resonant circuit.
  • the series resonant circuit vibrates practically undamped, which creates a high voltage across the capacitor (and the inductor).
  • the current flowing in the series circuit preheats the electrodes of the fluorescent lamp which has not yet been ignited.
  • the fluorescent lamp is ignited by the relatively high voltage across the capacitor. After ignition, the series resonant circuit is damped by the resistance of the fluorescent lamp, but the oscillating conditions are retained.
  • the series resonant circuit oscillates in the damped state with a lower resonance frequency.
  • a switching device with a plurality of transistors is provided, which is switched on every half-wave of the oscillation of the series resonant circuit feed a corresponding current in the correct phase into the series resonant circuit. This requires at least two transistors operated in phase opposition. This means that one transistor must be blocked when the other is conductive.
  • Such electronic ballasts have the advantage that the ignition takes place immediately after switching on the supply voltage with certainty, so that the fluorescent lamp is ignited immediately. Another advantage is that the power loss is considerably reduced compared to conventional ballasts.
  • One difficulty is that it is essential to ensure that the two transistors of the switching device are never conductive at the same time, since otherwise a short circuit would occur between the poles of the supply voltage.
  • the simultaneous conduction of the two transistors can be caused by interference pulses which occur during the A transistor is switched on or off and leads to unwanted switching of a transistor via base-emitter and base-collector capacitances. These interference pulses are difficult to avoid, especially on steep switching edges. However, steep switching edges are necessary in order to keep the switch-on and switch-off losses of the transistors as small as possible.
  • the invention has for its object to provide an electronic ballast of the type mentioned, in which the difficulty of controlling two transistors in phase opposition to maintain the oscillation condition of the series resonant circuit is avoided and which is thus more reliable and has a simplified circuit structure.
  • the invention provides that the switching device has a single electronic switch connected in series with a reactance on the supply voltage.
  • the current is fed to maintain the oscillation condition in the series resonant circuit under the control of a single electronic switching element, which can be a transistor.
  • this switching element is connected in series with a reactance, such as a coil.
  • a current is fed into the series resonant circuit only once during each full period of the oscillation, the opposite phase
  • the electronic switching element can be a transistor or a plurality of synchronously controlled transistors connected in series or in parallel. It is only important that only a single switch-on and switch-off process is carried out for feeding current into the series resonant circuit.
  • the capacitor of the series resonant circuit is connected to a pole of the supply voltage via a second capacitor of substantially larger capacitance.
  • the reactance is expediently a coil whose inductance is so large that it limits the current flowing through the switch below the permissible maximum value when the switch is conductive, and so small that the current flowing through it when the electronic switch is blocked is used to maintain the oscillation condition of the Fluorescent lamp damped series resonant circuit is sufficient.
  • the inductance and the capacitor of the series resonant circuit are dimensioned under the condition that the resonance frequency in the state damped by the fluorescent lamp should be greater than 20 kHz, so that the frequency of the vibrations lies above the hearing threshold of the human ear.
  • the Capacitance of the capacitor must be large enough to be able to supply the fluorescent lamp.
  • the coil is magnetically coupled in opposite directions to an auxiliary coil, which is connected in series with a rectifier element between the poles of the supply voltage, in order to store the energy released in this case.
  • auxiliary coil which is connected in series with a rectifier element between the poles of the supply voltage, in order to store the energy released in this case.
  • a voltage is generated in the auxiliary coil, which causes the energy to flow back into the output or smoothing capacitor of the DC voltage source. This ensures that the current consumption of the DC voltage source from the network is lower.
  • the rectifier element prevents the capacitor from being discharged via the auxiliary coil.
  • the fluorescent lamp can be connected in parallel to the capacitor of the series resonant circuit and the inductance of the series resonant circuit is connected to the connection point between the coil and the electronic switching element.
  • One electrode of the electronic switching element is grounded. This creates a favorable reference potential (ground) for controlling the electronic switch.
  • a DC voltage builds up at the output of the DC voltage source, but an additional trigger is still required to start the oscillation of the series resonant circuit.
  • a series circuit comprising a resistor and a capacitor is connected between the poles of the supply voltage and the connection point between the resistor and capacitor is connected to the control electrode of the electronic switch via a component with threshold behavior. Only when the DC voltage has exceeded a certain threshold value and the capacitor is charged to a certain degree, is the electronic switching element activated, which thereby becomes conductive. The series resonant circuit is triggered by the associated current surge.
  • the electronic ballast according to FIG. 1 has a low-pass filter 10 on the input side, which prevents high-frequency interference voltages from the ballast from being fed into the network.
  • the pass frequency of the low-pass filter 10 is therefore tuned to the network frequency.
  • the low-pass filter 10 is connected to the DC voltage source 11, which has a full-wave rectifier and a switching part which is not of interest here.
  • the mains voltage is supplied to the input of the DC voltage source via the low-pass filter 10 and a constant DC voltage is produced at the output of the DC voltage source, which is supplied as a supply voltage to the switching device 12 shown in detail in FIG.
  • a smoothing and storage capacitor 13 is connected between the poles of the supply voltage.
  • a fluorescent lamp 14 is connected on the output side to the switching device 12 and has an electrode 15, 16 at the opposite ends of a glass tube.
  • Each of the electrodes 15, 16 consists of a wire with two contact pins provided at its ends.
  • the switching device contains a series resonant circuit consisting of an inductor 17 in the form of a coil and a capacitor 18.
  • the electrode 15 connects the inductor 17 to the capacitor 18 and the Electrode 16 connects capacitor 18 to a second capacitor 19, the other leg of which is connected to ground 20.
  • the fluorescent lamp 14 is connected in parallel with the capacitor 18 in this way.
  • the series resonant circuit 17, 18 is practically undamped, while after the fluorescent lamp 14 is ignited it is damped by the resistance of the fluorescent lamp.
  • the end of the inductor 17 facing away from the capacitor 18 is connected to the collector of the electronic switching element 21 designed as an NPN transistor and to one end of the coil 22.
  • the emitter of the switching element 21 is grounded and the other end of the coil 22 is connected to the positive pole 23 of the DC voltage source.
  • the coil 22 is magnetically coupled to an auxiliary coil 24 which is wound in the opposite direction to the coil 22, which is indicated in FIG. 2 by the dots.
  • the auxiliary coil 24 is in series with a rectifier element 25 between the poles 20 and 23 of the DC voltage source.
  • a series circuit comprising a resistor 26 and a capacitor 27.
  • the connection point of these two components is via a component 28 with threshold behavior, e.g. a DIAC, connected to the collector of the electronic switching element 21.
  • the collector is also connected to a control coil 29, the other end of which is connected to ground potential and which is magnetically coupled to a sensor coil 30 which is in series with the inductor 17.
  • the DC voltage builds up between the poles 20 and 23, as a result of which the capacitor 13 is exposed.
  • the capacitor 27 is charged via the resistor 26, and the capacitors 18 and 19 are charged via the inductors 22 and 17.
  • the electronic switching element becomes conductive, so that a current flows from the positive pole 23 via the coil 22 and the electronic switching element 21 to ground and the series resonant circuit 17, 18 begins to oscillate .
  • This oscillation is transmitted via the coils 30, 29 to the base of the electronic switching element 21, which subsequently opens and closes in the rhythm of the oscillation of the series oscillating circuit 17, 18.
  • the DIA C 28 is dimensioned so that it locks after the supply voltage has been completely built up, so that it only has a short time after the device has been switched on
  • the electrodes 15, 16 lying in the series resonant circuit are preheated by the now flowing sinusoidal current.
  • the fluorescent lamp 14 ignites and dampens the series resonant circuit through its internal resistance. This reduces the amplitude and frequency of the vibration.
  • the components are selected so that when the fluorescent lamp 14 is lit, the voltage across the capacitor 18 corresponds to the nominal lamp voltage.
  • the switching element 21 now switches synchronously with the resonance frequency of the damped resonant circuit.
  • the auxiliary coil 24 is provided, which absorbs the energy stored in the coil 22 when the switching element 21 is switched into the blocking state and supplies it to the smoothing and storage capacitor 13 via the rectifier element 25.
  • the switching device 12 can also be used to supply several fluorescent lamps. This is indicated in FIG. 2 by the dashed lines 31, 32. If several fluorescent lamps are supplied, e.g. A separate series resonant circuit 17, 18 is provided for each fluorescent lamp and all series resonant circuits are connected in parallel.

Abstract

The ballast has a series oscillator (17, 18), the capacitor (18) of which is connected in parallel with the fluorescent lamp (14). The current supply to the series oscillator (17, 18) takes place via a coil (22) controlled by a single electronic switching element (21) which switches on and off as a function of the oscillator current. <IMAGE>

Description

Die Erfindung betrifft ein elektronisches Vorschaltgerät für mindestens eine Leuchtstofflampe, mit einem eine Induktivität und einen Kondensator enthaltenden Reihenschwingkreis, dessem Kapazität oder Induktivität die Leuchtstofflampe parallelschaltbar ist, und mit einer an eine Gleichspannungsquelle angeschlossenen elektronischen Schalteinrichtung zum phasengerechten periodischen Einspeisen eines Stromes in den Reihenschwingkreis.The invention relates to an electronic ballast for at least one fluorescent lamp, with a series resonant circuit containing an inductor and a capacitor, the capacitance or inductance of which the fluorescent lamp can be connected in parallel, and with an electronic switching device connected to a direct voltage source for phase-appropriate periodic feeding of a current into the series resonant circuit.

Die bisher üblichen Vorschaltgeräte für Leuchtstofflampen haben ein Bimetellelement, das den Stromfluß durch eine Spule bei Erwärmung unterbricht, um an der Spule eine Hochspannung zum Zünden der Leuchtstofflampe zu erzeugen. Infolge der thermischenThe previously common ballasts for fluorescent lamps have a bimetallic element which interrupts the flow of current through a coil when heated in order to generate a high voltage on the coil for igniting the fluorescent lamp. As a result of the thermal

Trägheit erfolgen die einzelnen Zündversuche in großen zeitlichen Abständen, was ein Flackern und eine verspätete Zündung der Leuchtstofflampe zur Folge hat. Nachteilig ist ferner der große Energieverbrauch des Vorschaltgerätes durch die zu der Leuchtstofflampe in Reihe geschaltete Spule, die während des Betriebes der Leuchtstofflampe ständig stromdurchflossen ist.The individual ignition attempts are slow at long intervals, which results in flickering and delayed ignition of the fluorescent lamp. Another disadvantage is the high energy consumption of the ballast due to the coil connected in series with the fluorescent lamp, which coil is constantly supplied with current during operation of the fluorescent lamp.

Zur Vermeidung dieser Nachteile sind elektronische Vorschaltgeräte entwickelt worden, die einen aus einer Induktivität und einem Kondensator bestehenden Reihenschwingkreis enthalten, dessen Resonanzfrequenz oberhalb von 20 kHz liegt. Dem Kondensator des Reihenschwingkreises wird die Leuchtstofflampe parallelgeschaltet. Bei nichtgezündeter Leuchtstofflampe schwingt der Reihenschwingkreis praktisch ungedämpft, wodurch an dem Kondensator (und an der Induktivität) eine hohe Spannung entsteht. Durch den im Reihenstromkreis fließenden Strom werden die Elektroden der noch nicht gezündeten Leuchtstofflampe vorgeheizt. Das Zünden der Leuchtstofflampe erfolgt durch die relativ hohe Spannung am Kondensator. Nach dem Zünden wird der Reihenschwingkreis durch den Widerstand der Leuchtstofflampe gedämpft, jedoch bleiben die Schwingbedingungen erhalten. Der Reihenschwingkreis schwingt aber im gedämpften Zustand mit einer geringeren Resonanzfrequenz. Zur Aufrechterhaltung der Schwingung des Reihenschwingkreises ist eine Schalteinrichtung mit mehreren Transistoren vorgesehen, die bei jeder Halbwelle der Schwingung des Reihenschwingkreises einen entsprechenden Strom phasenrichtig in den Reihenschwingkreis einspeisen. Hierzu sind mindestens zwei gegenphasig betriebene Transistoren erforderlich. Dies bedeutet, daß der eine Transistor gesperrt sein muß, wenn der andere leitend ist.To avoid these disadvantages, electronic ballasts have been developed which contain a series resonant circuit consisting of an inductor and a capacitor, the resonance frequency of which is above 20 kHz. The fluorescent lamp is connected in parallel to the capacitor of the series resonant circuit. When the fluorescent lamp is not ignited, the series resonant circuit vibrates practically undamped, which creates a high voltage across the capacitor (and the inductor). The current flowing in the series circuit preheats the electrodes of the fluorescent lamp which has not yet been ignited. The fluorescent lamp is ignited by the relatively high voltage across the capacitor. After ignition, the series resonant circuit is damped by the resistance of the fluorescent lamp, but the oscillating conditions are retained. However, the series resonant circuit oscillates in the damped state with a lower resonance frequency. In order to maintain the oscillation of the series resonant circuit, a switching device with a plurality of transistors is provided, which is switched on every half-wave of the oscillation of the series resonant circuit feed a corresponding current in the correct phase into the series resonant circuit. This requires at least two transistors operated in phase opposition. This means that one transistor must be blocked when the other is conductive.

Derartige elektronische Vorschaltgeräte haben den Vorteil, daß die Zündung unmittelbar nach dem Einschalten der Versorgungsspannung mit Sicherheit erfolgt, so daß die Leuchtstofflampe unverzüglich gezündet wird. Ein weiterer Vorteil besteht in der gegenüber den üblichen Vorschaltgeräten erheblich verringerten Verlustleistung. Eine Schwierigkeit besteht jedoch darin, daß unbedingt sichergestellt werden muß, daß die beiden Transistoren der Schalteinrichtung niemals gleichzeitig leitend sind, da anderenfalls ein Kurzschluß zwischen den Polen der Versorqunqsspannunq auftreten würde.. Das gleichzeitige Leiten der beiden Transistoren kann durch Störimpulse hervorgerufen werden, die beim Ein-oder Ausschalten eines Transistors auftreten und über Basis-Emitter- und Basis-Kollektor-Kapazitäten zu ungewolltem Schalten eines Transistors führen. Diese Störimpulse sind insbesondere bei steilen Schaltflanken schwer zu vermeiden. Steile Schaltflanken sind jedoch notwendig, um die Einschalt-und Ausschaltverluste der Transistoren möglichst klein zu halten.Such electronic ballasts have the advantage that the ignition takes place immediately after switching on the supply voltage with certainty, so that the fluorescent lamp is ignited immediately. Another advantage is that the power loss is considerably reduced compared to conventional ballasts. One difficulty, however, is that it is essential to ensure that the two transistors of the switching device are never conductive at the same time, since otherwise a short circuit would occur between the poles of the supply voltage. The simultaneous conduction of the two transistors can be caused by interference pulses which occur during the A transistor is switched on or off and leads to unwanted switching of a transistor via base-emitter and base-collector capacitances. These interference pulses are difficult to avoid, especially on steep switching edges. However, steep switching edges are necessary in order to keep the switch-on and switch-off losses of the transistors as small as possible.

Eine weitere Schwierigkeit bei der Verwendung zweier gegenphasiger Transistoren besteht darin, daß dann, wenn diese Transistoren vom gleichen Typ sind (z.B. npn-Transistoren) und wenn beide Transistoren in Reihe geschaltet sind, die Ansteuerung dieser Transistoren galvanisch getrennt erfolgen muß. Hierzu sind zusätzliche Bauelemente in Form von Impuls-Transformatoren oder Opto-Kopplern notwendig.Another difficulty with the use of two antiphase transistors is that if these transistors are of the same type (e.g. npn transistors) and if both transistors are connected in series, the activation of these transistors must be galvanically isolated. This requires additional components in the form of pulse transformers or opto-couplers.

Der Erfindung liegt die Aufgabe zugrunde, ein elektronisches Vorschaltgerät der eingangs genannten Art zu schaffen, bei dem die Schwierigkeit der gegenphasigen Ansteuerung zweier Transistoren zur Aufrechterhaltung der Schwingbedingung des Reihenschwingkreises vermieden wird und das somit betriebssicherer ist und einen vereinfachten Schaltungsaufbau hat.The invention has for its object to provide an electronic ballast of the type mentioned, in which the difficulty of controlling two transistors in phase opposition to maintain the oscillation condition of the series resonant circuit is avoided and which is thus more reliable and has a simplified circuit structure.

Zur Lösung dieser Aufgabe ist erfindungsgemäß vorgesehen, daß die Schalteinrichtung einen in Reihe mit einem Blindwiderstand an der Versorgungsspannung liegenden einzigen elektronischen Schalter aufweist.To achieve this object, the invention provides that the switching device has a single electronic switch connected in series with a reactance on the supply voltage.

Nach der Erfindung erfolgt die Einspeisung des Stromes zur Aufrechterhaltung der Schwingungsbedingung in den Reihenschwingkreis unter Steuerung durch ein einziges elektronisches Schaltelement, das ein Transistor sein kann. Zur Vermeidung von Leistungsverlusten ist dieses Schaltelement mit einem Blindwiderstand, z.B. einer Spule, in Reihe geschaltet. In den Reihenschwingkreis wird während jeder Vollperiode der Schwingung nur einmal ein Strom eingespeist, wobei die gegenphasigeAccording to the invention, the current is fed to maintain the oscillation condition in the series resonant circuit under the control of a single electronic switching element, which can be a transistor. To avoid power losses, this switching element is connected in series with a reactance, such as a coil. A current is fed into the series resonant circuit only once during each full period of the oscillation, the opposite phase

Einspeisung unterbleibt. Hierdurch wird die Gefahr eines durch Störimpulse verursachten Kurzschlusses zwischen den Polen der Versorgungsspannung bzw. eines Kurzschlusses am Reihenschwingkreis vermieden.No feed-in. This avoids the risk of a short circuit caused by interference pulses between the poles of the supply voltage or a short circuit on the series resonant circuit.

Bei dem elektronischen Schaltelement kann es sich um einen Transistor oder um mehrere synchron angesteuerte, in Reihe oder parallelgeschaltete Transistoren handeln. Wichtig ist nur, daß zur Einspeisung von Strom in den Reihenschwingkreis nur ein einziger Einschalt- und Ausschaltvorgang durchgeführt wird.The electronic switching element can be a transistor or a plurality of synchronously controlled transistors connected in series or in parallel. It is only important that only a single switch-on and switch-off process is carried out for feeding current into the series resonant circuit.

Gemäß einer bevorzugten Ausführungsform der Erfindung ist der Kondensator des Reihenschwingkreises über einen zweiten Kondensator wesentlich größerer Kapazität mit einem Pol der Versorgungsspannung verbunden.According to a preferred embodiment of the invention, the capacitor of the series resonant circuit is connected to a pole of the supply voltage via a second capacitor of substantially larger capacitance.

Der Blindwiderstand ist zweckmäßigerweise eine Spule, deren Induktivität so groß ist, daß sie bei leitendem Schalter den durch den Schalter fließenden Strom unter den zulässigen Höchstwert begrenzt,und so klein, daß bei gesperrtem elektronischen Schalter der sie durchfließende Strom zur Aufrechterhaltung der Schwingbedingung des durch die Leuchtstofflampe gedämpften Reihenschwingkreises ausreicht. Die Bemessung der Induktivität und des Kondensators des Reihenschwingkreises erfolgt unter der Bedingung, daß die Resonanzfrequenz im durch die Leuchtstofflampe gedämpften Zustand größer sein soll als 20 kHz, so daß die Frequenz der Schwingungen oberhalb der Hörschwelle des menschlichen Ohres liegt. Andererseits muß die Kapazität des Kondensators groß genug sein, um die Leuchtstofflampe versorgen zu können. Aus diesen Randbedingungen kann der Fachmann die Dimensionierung der elektrischen Bauteile des Reihenschwingkreises vornehmen. Die Bemessung der mit dem elektronischen Schaltelement in Reihe liegenden Spule erfolgt dann anschließend nach den oben angegebenen Kriterien. Wichtig ist, daß die Induktivität der zweiten Spule wesentlich kleiner ist als die Induktivität im Reihenschwingkreis.The reactance is expediently a coil whose inductance is so large that it limits the current flowing through the switch below the permissible maximum value when the switch is conductive, and so small that the current flowing through it when the electronic switch is blocked is used to maintain the oscillation condition of the Fluorescent lamp damped series resonant circuit is sufficient. The inductance and the capacitor of the series resonant circuit are dimensioned under the condition that the resonance frequency in the state damped by the fluorescent lamp should be greater than 20 kHz, so that the frequency of the vibrations lies above the hearing threshold of the human ear. On the other hand, the Capacitance of the capacitor must be large enough to be able to supply the fluorescent lamp. From these boundary conditions, a person skilled in the art can dimension the electrical components of the series resonant circuit. The coil in series with the electronic switching element is then dimensioned according to the criteria specified above. It is important that the inductance of the second coil is significantly smaller than the inductance in the series resonant circuit.

Jedesmal, wenn das elektronische Schaltelement in den Sperrzustand gesteuert wird, verringert sich der durch die Spule fließende Strom. Diese Stromänderung bewirkt den Aufbau einer hohen Spannung an der Spule. Zur Speicherung der hierbei freiwerdenden Energie ist in vorteilhafter Weiterbildung der Erfindung die Spule magnetisch gegensinnig mit einer Hilfsspule gekoppelt, die in Reihe mit einem Gleichrichterelement zwischen den Polen der Versorgungsspannung liegt. Bei jedem Abschaltvorgang des Schaltelementes wird in der Hilfsspule eine Spannung erzeugt, die einen Rückfluß der Energie in den Ausgangs- oder Glättungskondensator der Gleichspannungsquelle bewirkt. Dadurch wird erreicht, daß die Stromaufnahme der Gleichspannungsquelle aus dem Netz geringer wird. Das Gleichrichterelement verhindert eine Entladung des Kondensators über die Hilfsspule.Every time the electronic switching element is controlled in the blocking state, the current flowing through the coil is reduced. This change in current causes a high voltage to build up on the coil. In an advantageous further development of the invention, the coil is magnetically coupled in opposite directions to an auxiliary coil, which is connected in series with a rectifier element between the poles of the supply voltage, in order to store the energy released in this case. Each time the switching element is switched off, a voltage is generated in the auxiliary coil, which causes the energy to flow back into the output or smoothing capacitor of the DC voltage source. This ensures that the current consumption of the DC voltage source from the network is lower. The rectifier element prevents the capacitor from being discharged via the auxiliary coil.

Bei einer bevorzugten Ausführungsform der Erfindung ist die Leuchtstofflampe dem Kondensator des Reihenschwingkreises parallelschaltbar und die Induktivität des Reihenschwingkreises ist mit dem Verbindungspunkt zwischen der Spule und dem elektronischen Schaltelement verbunden. Eine Elektrode des elektronischen Schaltelementes liegt an Masse. Hierdurch wird ein günstiges Bezugspontential (Masse) zur Steuerung des elektronischen Schalters geschaffen.In a preferred embodiment of the invention, the fluorescent lamp can be connected in parallel to the capacitor of the series resonant circuit and the inductance of the series resonant circuit is connected to the connection point between the coil and the electronic switching element. One electrode of the electronic switching element is grounded. This creates a favorable reference potential (ground) for controlling the electronic switch.

Nach dem Einschalten des elektronischen Vorschaltgerätes baut sich am Ausgang der Gleichspannungsquelle eine Gleichspannung auf, jedoch bedarf es noch eines zusätzlichen Anstosses, um die Schwingung des Reihenschwingkreises in Gang zu setzen. Hierzu ist gemäß einer vorteilhaften Weiterbildung der Erfindung eine Reihenschaltung aus einem Widerstand und einem Kondensator zwischen die Pole der` Versorgungsspannung geschaltet und der Verbindungspunkt zwischen Widerstand und Kondensator ist über ein Bauteil mit Schwellwertverhalten an die Steuerelektrode des elektronischen Schalters angeschlossen. Erst wenn die Gleichspannung einen bestimmten Schwellwert überschritten hat und der Kondensator bis zu einem gewissen Grade aufgeladen ist, erfolgt die Ansteuerung des elektronischen Schaltelementes, das dadurch leitend wird. Durch den hiermit verbundenen Stromstoß wird der Reihenschwingkreis angestoßen.After switching on the electronic ballast, a DC voltage builds up at the output of the DC voltage source, but an additional trigger is still required to start the oscillation of the series resonant circuit. For this purpose, according to an advantageous development of the invention, a series circuit comprising a resistor and a capacitor is connected between the poles of the supply voltage and the connection point between the resistor and capacitor is connected to the control electrode of the electronic switch via a component with threshold behavior. Only when the DC voltage has exceeded a certain threshold value and the capacitor is charged to a certain degree, is the electronic switching element activated, which thereby becomes conductive. The series resonant circuit is triggered by the associated current surge.

Zur Steuerung des elektronischen Schaltelementes ist dessen Elektrode an eine von dem Schwingkreisstrom gesteuerte Steuerspule angeschlossen.To control the electronic switching element, its electrode is connected to a control coil controlled by the oscillating circuit current.

Im folgenden wird unter Bezugnahme auf die Zeichnungen ein Ausführungsbeispiel der Erfindung näher erläutert.In the following an embodiment of the invention will be explained with reference to the drawings.

Es zeigen:

  • Fig. 1 ein Blockschaltbild des gesamten Vorschaltgerätes und
  • Fig. 2 den Aufbau der Schalteinrichtung.
Show it:
  • Fig. 1 is a block diagram of the entire ballast and
  • Fig. 2 shows the structure of the switching device.

Das elektronische Vorschaltgerät nach Figur 1 weist eingangsseitig ein Tiefpassfilter 10 auf, das verhindert, daß hochfrequente Störspannungen aus dem Vorschaltgerät in das Netz eingespeist werden. Die Durchlaßfrequenz des Tiefpassfilters 10 ist also auf die Netzfrequenz abgestimmt. Das Tiefpassfilter 10 ist mit der Gleichspannungsquelle 11 verbunden, die einen Doppelweggleichrichter sowie einen hier nicht näher interessierenden Schaltteil aufweist. Dem Eingang der Gleichspannungsquelle wird über das Tiefpassfilter 10 die Netzspannung zugeführt und am Ausgang der Gleichspannungsquelle entsteht eine konstante Gleichspannung, die der in Figur 2 detailliert dargestellten Schalteinrichtung 12 als Versorgungsspannung zugeführt wird. Zwischen die Pole der Versorgungsspannung ist ein Glättungs- und Speicherkondensator 13 geschaltet.The electronic ballast according to FIG. 1 has a low-pass filter 10 on the input side, which prevents high-frequency interference voltages from the ballast from being fed into the network. The pass frequency of the low-pass filter 10 is therefore tuned to the network frequency. The low-pass filter 10 is connected to the DC voltage source 11, which has a full-wave rectifier and a switching part which is not of interest here. The mains voltage is supplied to the input of the DC voltage source via the low-pass filter 10 and a constant DC voltage is produced at the output of the DC voltage source, which is supplied as a supply voltage to the switching device 12 shown in detail in FIG. A smoothing and storage capacitor 13 is connected between the poles of the supply voltage.

An die Schalteinrichtung 12 ist ausgangsseitig eine Leuchtstofflampe 14 angeschlossen, die an den entgegengesetzten Enden eines Glasrohres jeweils eine Elektrode 15, 16 aufweist. Jede der Elektroden 15, 16 besteht aus einem Draht mit zwei an seinen Enden vorgesehenen Kontaktstiften.A fluorescent lamp 14 is connected on the output side to the switching device 12 and has an electrode 15, 16 at the opposite ends of a glass tube. Each of the electrodes 15, 16 consists of a wire with two contact pins provided at its ends.

Wie Figur 2 zeigt, enthält die Schalteinrichtung einen Reihenschwingkreis aus einer Induktivität 17 in Form einer Spule und einem Kondensator 18. Wenn die Leuchtstofflampe 14 in die (nicht dargestellte) Lampenfassung eingesetzt wird, verbindet die Elektrode 15 die Induktivität 17 mit dem Kondensator 18 und die Elektrode 16 verbindet den Kondensator 18 mit einem zweiten Kondensator 19, dessen anderes Bein mit Masse 20 verbunden ist. Die Leuchtstofflampe 14 ist auf diese Weise dem Kondensator 18 parallelgeschaltet. Vor dem Zünden ist der Reihenschwingkreis 17, 18 praktisch unbedämpft, während er nach dem Zünden der Leuchtstofflampe 14 durch den Widerstand der Leuchtstofflampe bedämpft ist.As FIG. 2 shows, the switching device contains a series resonant circuit consisting of an inductor 17 in the form of a coil and a capacitor 18. When the fluorescent lamp 14 is inserted into the lamp holder (not shown), the electrode 15 connects the inductor 17 to the capacitor 18 and the Electrode 16 connects capacitor 18 to a second capacitor 19, the other leg of which is connected to ground 20. The fluorescent lamp 14 is connected in parallel with the capacitor 18 in this way. Before the ignition, the series resonant circuit 17, 18 is practically undamped, while after the fluorescent lamp 14 is ignited it is damped by the resistance of the fluorescent lamp.

Das dem Kondensator 18 abgewandte Ende der Induktivität 17 ist an den Kollektor des als npn-Transistor ausgebildeten elektronischen Schaltelementes 21 und an das eine Ende der Spule 22 angeschlossen. Der Emitter des Schaltelementes 21 liegt an Masse und das andere Ende der Spule 22 ist mit dem positiven Pol 23 der Gleichspannungsquelle verbunden.The end of the inductor 17 facing away from the capacitor 18 is connected to the collector of the electronic switching element 21 designed as an NPN transistor and to one end of the coil 22. The emitter of the switching element 21 is grounded and the other end of the coil 22 is connected to the positive pole 23 of the DC voltage source.

Die Spule 22 ist magnetisch mit einer Hilfsspule 24 gekoppelt, die gegensinnig zur Spule 22 gewickelt ist, was in Figur 2 durch die Punkte angedeutet ist. Die Hilfsspule 24 liegt in Reihe mit einem Gleichrichterelement 25 zwischen den Polen 20 und 23 der Gleichspannungsquelle.The coil 22 is magnetically coupled to an auxiliary coil 24 which is wound in the opposite direction to the coil 22, which is indicated in FIG. 2 by the dots. The auxiliary coil 24 is in series with a rectifier element 25 between the poles 20 and 23 of the DC voltage source.

Zwischen den Polen 20 und 23 liegt weiterhin eine Reihenschaltung aus einem Widerstand 26 und einem Kondensator 27. Der Verbindungspunkt dieser beiden Bauelemente ist über ein Bauelement 28 mit Schwellwertverhalten, z.B. einen DIAC, an den Kollektor des elektronischen Schaltelementes 21 angeschlossen. Der Kollektor ist ferner mit einer Steuerspule 29 verbunden, deren anderes Ende an Massepotential liegt und die mit einer mit der Induktivität 17 in Reihe liegenden Fühlerspule 30 magnetisch gekoppelt ist.Between the poles 20 and 23 there is also a series circuit comprising a resistor 26 and a capacitor 27. The connection point of these two components is via a component 28 with threshold behavior, e.g. a DIAC, connected to the collector of the electronic switching element 21. The collector is also connected to a control coil 29, the other end of which is connected to ground potential and which is magnetically coupled to a sensor coil 30 which is in series with the inductor 17.

Im folgenden wird die Funktionsweise der Schaltung nach Figur 2 erläutert.The mode of operation of the circuit according to FIG. 2 is explained below.

Nach dem Einschalten der Netzspannung baut sich zwischen den Polen 20 und 23 die Gleichspannung auf, wodurch der Kondensator 13 aufqelagen wird. Gleichzeitig laden sich über den Widerstand 26 der Kondensator 27, sowie über die Induktivitäten 22 und 17 die Kondensatoren 18 und 19 auf. Wenn die Spannung am Kondensator 27 den Schwellwert des DIAC 28 überschritten hat, wird das elektronische Schaltelement leitend, so daß ein Strom von dem positiven Pol 23 über die Spule 22 und das elektronische Schaltelement 21 nach Masse fließt und der Reihenschwingkreis 17, 18 zu schwingen beginnt. Diese Schwingung wird über die Spulen 30, 29 auf die Basis des elektronischen Schaltelementes 21 übertragen, das nachfolgend im Rhythmus der Schwingung des Reihenschwinqkreises 17, 18 öffnet und schließt. Der DIAC 28 ist so bemessen, daß er nach dem vollständigen Aufbau der Versorgungsspannung sperrt, so daß er nur nach dem Einschalten des Gerätes kurzzeitig einen einzigenAfter switching on the mains voltage, the DC voltage builds up between the poles 20 and 23, as a result of which the capacitor 13 is exposed. At the same time, the capacitor 27 is charged via the resistor 26, and the capacitors 18 and 19 are charged via the inductors 22 and 17. When the voltage across the capacitor 27 has exceeded the threshold value of the DIAC 28, the electronic switching element becomes conductive, so that a current flows from the positive pole 23 via the coil 22 and the electronic switching element 21 to ground and the series resonant circuit 17, 18 begins to oscillate . This oscillation is transmitted via the coils 30, 29 to the base of the electronic switching element 21, which subsequently opens and closes in the rhythm of the oscillation of the series oscillating circuit 17, 18. The DIA C 28 is dimensioned so that it locks after the supply voltage has been completely built up, so that it only has a short time after the device has been switched on

Stromimpuls zu dem Schaltelement 21 durchlässt, um die Schwingung einzuleiten.Passes current pulse to the switching element 21 to initiate the vibration.

Nach dem Einschalten des Vorschaltgerätes und dem Beginn des Schwingvorganges des Reihenschwingkreises 17, 18 werden die in dem Reihenschwingkreis liegenden Elektroden 15, 16 durch den nun fließenden sinusförmigen Strom vorgeheizt. Nach Erreichen einer ausreichend hohen Spannung am Kondensator 18 zündet die Leuchtstofflampe 14 und bedämpft durch ihren Innenwiderstand den Reihenschwingkreis. Dadurch verringern sich Amplitude und Frequenz der Schwingung. Die Bauelemente sind so gewählt, daß bei gezündeter Leuchtstofflampe 14 die Spannung am Kondensator 18 der Lampen-Nennspannung entspricht. Das Schaltelement 21 schaltet nun synchron zur Resonanzfrequenz des gedämpften Schwingkreises.After switching on the ballast and starting the oscillation process of the series resonant circuit 17, 18, the electrodes 15, 16 lying in the series resonant circuit are preheated by the now flowing sinusoidal current. After reaching a sufficiently high voltage across the capacitor 18, the fluorescent lamp 14 ignites and dampens the series resonant circuit through its internal resistance. This reduces the amplitude and frequency of the vibration. The components are selected so that when the fluorescent lamp 14 is lit, the voltage across the capacitor 18 corresponds to the nominal lamp voltage. The switching element 21 now switches synchronously with the resonance frequency of the damped resonant circuit.

Um beim Sperren des Schaltelementes 21 Spannungsspitzen am Kollektor zu vermeiden, ist die Hilfsspule 24 vorgesehen, die beim Umschalten des Schaltelementes 21 in den Sperrzustand die in der Spule 22 gespeicherte Energie aufnimmt und über das Gleichrichterelement 25 dem Glättungs- und Speicherkondensator 13 zuführt.In order to avoid voltage peaks at the collector when the switching element 21 is blocked, the auxiliary coil 24 is provided, which absorbs the energy stored in the coil 22 when the switching element 21 is switched into the blocking state and supplies it to the smoothing and storage capacitor 13 via the rectifier element 25.

Die Schalteinrichtung 12 kann auch für die Versorgung mehrerer Leuchtstofflampen benutzt werden. Dies ist in Figur 2 durch die gestrichelten Linien 31, 32 angedeutet. Im Falle der Versorgung mehrerer Leuchtstofflampen ist z.B. für jede Leuchtstofflampe ein eigener Reihenschwingkreis 17, 18 vorgesehen und sämtliche Reihenschwingkreise sind parallel geschaltet.The switching device 12 can also be used to supply several fluorescent lamps. This is indicated in FIG. 2 by the dashed lines 31, 32. If several fluorescent lamps are supplied, e.g. A separate series resonant circuit 17, 18 is provided for each fluorescent lamp and all series resonant circuits are connected in parallel.

Claims (7)

1. Elektronisches Vorschaltgerät für mindestens eine Leuchtstofflampe, mit einem eine Induktivität und einen Kondensator enthaltenden Reihenschwingkreis, dessem Kondensator oder Induktivität die Leuchtstofflampe parallelschaltbar ist, und mit einer an eine Gleichspannungsquelle angeschlossenen elektronischen Schalteinrichtung zum phasengerechten periodischen Einspeisen eines Stromes in den Reihenschwingkreis, dadurch gekennzeichnet , daß die Schalteinrichtung (12) einen in Reihe mit einem Blindwiderstand (22) an der Versorgungsspannung liegenden einzigen elektronischen Schalter (21) aufweist.1. Electronic ballast for at least one fluorescent lamp, with a series resonant circuit containing an inductor and a capacitor, the capacitor or inductor of which the fluorescent lamp can be connected in parallel, and with an electronic switching device connected to a direct voltage source for phase-appropriate periodic feeding of a current into the series resonant circuit, characterized in that that the switching device (12) has a single electronic switch (21) connected in series with a reactance (22) to the supply voltage. 2. Elektronisches Vorschaltgerät nach Anspruch 1, dadurch gekennzeichnet, daß der Kondensator (18) des Reihenschwingkreises (17, 18) über einen zweiten Kondensator (19) wesentlich größerer Kapazität mit einem Pol (20) der Versorgungsspannung verbunden ist.2. Electronic ballast according to claim 1, characterized in that the capacitor (18) of the series resonant circuit (17, 18) is connected via a second capacitor (19) of substantially larger capacitance to one pole (20) of the supply voltage. 3. Elektronisches Vorschaltgerät nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß der Blindwiderstand eine Spule (22) ist, deren Induktivität so groß ist, daß sie bei leitendem elektronischen Schalter (21) den durch den Schalter (21) fließenden Strom unter den zulässigen Höchstwert begrenzt,und so klein, daß bei gesperrtem elektronischen Schalter (21) der sie durchfließende Strom zur Aufrechterhaltung der Schwingbedingung des durch die Leuchtstofflampe (14) gedämpften Reihenschwingkreises (17, 18) ausreicht.3. Electronic ballast according to claim 1 or 2, characterized in that the reactance is a coil (22), the inductance is so large that, when the electronic switch (21) is conductive, the current flowing through the switch (21) is below the permissible Maximum value limited, and so small that when the electronic switch (21) is blocked, the current flowing through it is sufficient to maintain the oscillation condition of the series resonant circuit (17, 18) damped by the fluorescent lamp (14). 4. Elektronisches Vorschaltgerät nach Anspruch 3, dadurch gekennzeichnet, daß die Spule (22) magnetisch gegensinnig mit einer Hilfsspule (24) gekoppelt ist, die in Reihe mit einem Gleichrichterelement (25) zwischen den Polen der Versorgungsspannung liegt.4. Electronic ballast according to claim 3, characterized in that the coil (22) is magnetically coupled in opposite directions to an auxiliary coil (24) which is in series with a rectifier element (25) between the poles of the supply voltage. 5. Elektronisches Vorschaltgerät nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, daß die Leuchtstofflampe (14) dem Kondensator (18) des Reihenschwingkreises (17, 18) parallelschaltbar ist, daß die Induktivität (17) des Reihenschwingkreises mit dem Verbindungspunkt zwischen der Spule (22) und dem elektronischen Schaltelement (21) verbunden ist, und daß eine Elektrode des elektronischen Schaltelementes (21) an Masse liegt.5. Electronic ballast according to one of claims 1 to 4, characterized in that the fluorescent lamp (14) the capacitor (18) of the series resonant circuit (17, 18) can be connected in parallel, that the inductance (17) of the series resonant circuit with the connection point between the coil (22) and the electronic switching element (21) is connected, and that an electrode of the electronic switching element (21) is grounded. 6. Elektronisches Vorschaltgerät nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, daß eine Reihenschaltung aus einem Widerstand (26) und einem Kondensator (27) zwischen die Pole (20, 23) der Versorgungsspannung geschaltet ist, und daß der Verbindungspunkt zwischen dem Widerstand (26) und dem Kondensator (27) über ein Bau- teil (28) mit Schwellwertverhalten an die Steuerelektrode des elektronischen Schaltelementes (21) angeschlossen ist.6. Electronic ballast according to one of claims 1 to 5, characterized in that a series circuit comprising a resistor (26) and a capacitor (27) is connected between the poles (20, 23) of the supply voltage, and that the connection point between the resistor (26) and the condenser (27) via a B au- part (28) is connected with threshold behavior to the control electrode of the electronic switching element (21). 7. Elektronisches Vorschaltgerät nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß die Steuerelektrode des elektronischen Schaltelementes (21) an eine von dem Schwingkreisstrom gesteuerte Steuerspule (29) angeschlossen ist.7. Electronic ballast according to one of the preceding claims, characterized in that the control electrode of the electronic switching element (21) is connected to a control coil (29) controlled by the oscillating circuit current.
EP82108398A 1981-09-24 1982-09-11 Electronic ballast for at least one fluorescent lamp Withdrawn EP0075774A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3137940 1981-09-24
DE19813137940 DE3137940C2 (en) 1981-09-24 1981-09-24 Electronic ballast for at least one fluorescent lamp

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EP0075774A2 true EP0075774A2 (en) 1983-04-06
EP0075774A3 EP0075774A3 (en) 1983-07-27

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS612299A (en) * 1984-06-14 1986-01-08 松下電器産業株式会社 Device for firing fluorescent lamp
EP0142063B1 (en) * 1983-10-19 1992-01-15 Hitachi Lighting, Ltd. Lighting apparatus for an electric discharge lamp
EP1139699A1 (en) * 2000-03-29 2001-10-04 Dura Lamp S.p.A. Arrangement for the suppression of current harmonics for electronic power supplies of compact fluorescent lamps

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0691750B2 (en) * 1983-01-14 1994-11-14 松下電工株式会社 Inverter device
JPS62100996A (en) * 1985-10-29 1987-05-11 株式会社　デンコ−社 Fluorescent lamp burner
DK89388D0 (en) * 1988-02-19 1988-02-19 Silver Gruppen Prod As ELECTRONIC BALLAST
US5138235A (en) * 1991-03-04 1992-08-11 Gte Products Corporation Starting and operating circuit for arc discharge lamp

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3710177A (en) * 1970-11-14 1973-01-09 Dahson Park Ind Ltd Fluorescent lamp circuit driven initially at lower voltage and higher frequency
DE1764624B2 (en) * 1967-07-28 1974-10-17 N.V. Philips' Gloeilampenfabrieken, Eindhoven (Niederlande) Device for igniting a gas and / or vapor discharge tube by means of a high-frequency voltage and for feeding this tube
US3882354A (en) * 1973-07-23 1975-05-06 Coleman Company Inverter ballast circuit for fluorescent lamp

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1281029B (en) * 1964-02-05 1968-10-24 Licentia Gmbh Transistor inverter
GB1453436A (en) * 1972-10-31 1976-10-20 Lucas Electrical Ltd Inverters
DE2941822A1 (en) * 1979-10-16 1981-04-30 Patra Patent Treuhand Ballast arrangement for operating low-pressure discharge lamps

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1764624B2 (en) * 1967-07-28 1974-10-17 N.V. Philips' Gloeilampenfabrieken, Eindhoven (Niederlande) Device for igniting a gas and / or vapor discharge tube by means of a high-frequency voltage and for feeding this tube
US3710177A (en) * 1970-11-14 1973-01-09 Dahson Park Ind Ltd Fluorescent lamp circuit driven initially at lower voltage and higher frequency
US3882354A (en) * 1973-07-23 1975-05-06 Coleman Company Inverter ballast circuit for fluorescent lamp

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0142063B1 (en) * 1983-10-19 1992-01-15 Hitachi Lighting, Ltd. Lighting apparatus for an electric discharge lamp
JPS612299A (en) * 1984-06-14 1986-01-08 松下電器産業株式会社 Device for firing fluorescent lamp
EP1139699A1 (en) * 2000-03-29 2001-10-04 Dura Lamp S.p.A. Arrangement for the suppression of current harmonics for electronic power supplies of compact fluorescent lamps

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EP0075774A3 (en) 1983-07-27
DE3137940C2 (en) 1985-08-29
DE3137940A1 (en) 1983-04-07

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