Abstract: A backlight assembly prevents abnormal discharge of a device using a high voltage to drive a discharge tube such as CCFL. An inverter circuit includes an inverter transformer supplying an AC high voltage to a plurality of discharge tubes, and a plurality of balance transformers. First terminals of primary coils of the balance transformers are connected to the discharge tubes, and second terminals of the primary coils are connected to a ground. Secondary coils of the balance transformers are connected in series to form a loop. A resistor has a first terminal connected to the loop and a second terminal connected to the ground. Accordingly, the backlight assembly may detect a high-voltage abnormal discharge such as a corona discharge, an arc discharge or the like.

Abstract: The coil component comprises a primary coil, and a first secondary coil and a second secondary coil which are opposed to the primary coil. A first terminal is a terminal of the first secondary coil, that is a terminal for connection to one end of a lamp, and a second terminal is a terminal of the second secondary coil, that is a terminal for connection to the other end of the lamp. The first secondary coil and the second secondary coil are coaxially disposed, and the first terminal and the second terminal are reverse in polarity.

Abstract: An inverter circuit includes a power supply which outputs an alternating current voltage, an inverter transformer having one primary coil connected to an output terminal of the power supply and pairs of secondary coils which supply an alternating current high voltage, induced by the one primary coil, to pairs of discharge tubes and a plurality of balance transformers having primary coils serially connected between respective pairs of the pairs of secondary coils of the inverter transformer, and having secondary coils corresponding to the primary coils of the plurality of balance transformers, wherein the secondary coils of the plurality of balance transformers are serially connected to form a loop.

Abstract: A transformer for driving multi-lamps and a backlight module thereof are provided. The transformer comprises a primary winding, a secondary winding, a core, a first bobbin and a second bobbin. The primary winding comprises a primary coil. The secondary winding comprises a secondary coil and a plurality of auxiliary coils whose turns are substantially equal. The core has a first side and a second side. The first bobbin and the second bobbin are respectively disposed on the first side and the second side for winding around the primary coil, the secondary coil and the auxiliary coils.

Abstract: A ballast operates lamps each including a pair of electrodes. A high frequency resonant circuit generates a high frequency bus, the resonant circuit is configured for operational coupling to the electrodes of each lamp, and includes a resonant inductor and a resonant capacitance.

Abstract: A ballast control integrated circuit for a ballast driving a high intensity discharge (HID) lamp. The control integrated circuit has a first circuit for controlling a DC to DC converter receiving a first DC voltage and providing an increased DC voltage. The first circuit includes a driver for providing a pulsed signal to drive a first switch coupled to a flyback transformer of the DC to DC converter. A second circuit controls a DC to AC converter, the second circuit controlling a switching circuit receiving the increased DC voltage and driving the HID lamp with an AC voltage. The second circuit has a driver circuit for driving the switching circuit. The switching circuit is an H-bridge switching circuit coupled to drive the HID lamp.

Abstract: In an inverter circuit, inverter transformers supply AC voltage to discharge tubes. The inverter transformers are arranged such that the AC voltage at a respective first terminal of each secondary coil has an opposite polarity with respect to a corresponding second terminal of each secondary coil. Balance transformers have primary coils inserted in series between a reference terminal of the secondary coils of the inverter transformers and ground. The secondary coils of the balance transformers are connected in series to form a loop. One node of the loop is grounded and a voltage detection node is located on the loop. At least one secondary coil of the secondary coils of the balance transformers is interposed between the grounded node of the loop and the voltage detection node. Thus, an abnormal state or condition, such as an open circuit or a short circuit may be detected.

Abstract: A phase sampling protection device substantially includes a phase sampling circuit coupled between a tube circuit and a protection circuit. The phase sampling circuit captures a voltage signal and a current phase signal of the tube circuit for comparison, using phase comparing technique to detect an anomaly of the tube, if the tube doesn't function normally, then the phase sampling circuit driving the protection circuit to shut down the power supply of the tube to keep a transformer from burning down and other safety issues from happening.

Abstract: A transformer includes a first bobbin, a second bobbin, a primary winding and at least four secondary windings. The first bobbin has a first primary winding area and at least two first secondary winding areas. The first primary winding area is located between the first secondary winding areas. The second bobbin is combined with the first bobbin and has a second primary winding area and at least two second secondary winding areas. The second primary winding area is located between the second secondary winding areas. The primary winding is wound around the first primary winding area and the second primary winding area. The secondary windings are respectively wound around the first secondary winding areas and the second secondary winding areas.

Abstract: A power supply circuit for a first and a second lamps and the transformer thereof is provided. The power supply circuit comprises a driving circuit and a transformer. The transformer includes a magnetic core, a primary coil set, a secondary coil, a first coil and a second coil. The driving circuit provides an alternative voltage. The primary coil set is wound on the magnetic core, along with the secondary coil, the first and the second coils, and receives the alternative voltage. The turns of the first coil and the second coil are substantially the same. The first lamp is coupled between the first coil and the secondary coil, and the second lamp is coupled between the second coil and the secondary coil.

Abstract: An inverter transformer includes a coil unit including a bobbin and a plurality of windings, and a transformer core unit. The bobbin is formed with a core-receiving compartment, and includes first, second and third coil winding portions. The windings are wound around the first, second and third coil winding portions, respectively. The transformer core unit has an internal core part that extends into the core-receiving compartment.

Abstract: A transformer for driving multi-lamps and a backlight module thereof are provided. The transformer comprises a primary winding, a secondary winding, a core, a first bobbin and a second bobbin. The primary winding comprises a primary coil. The secondary winding comprises a secondary coil and a plurality of auxiliary coils whose turns are substantially equal. The core has a first side and a second side. The first bobbin and the second bobbin are respectively disposed on the first side and the second side for winding around the primary coil, the secondary coil and the auxiliary coils.

Abstract: An electronic ballast circuit for a lamp is described, wherein the ballast comprises a power factor correction circuit coupled to an inverter circuit. The inverter circuit is further coupled to a trigger circuit, which is in turn operatively connected to a hot or neutral line of a power supply by a control line. Upon closing a switch in the control line, the trigger circuit operates to place a capacitor in parallel with a base drive winding of a transistor in the inverter circuit, causing the inverter circuit to shut down. When the switch is opened, the trigger circuit shuts off and the inverter starts up and returns to an oscillating state.

Abstract: A discharge tube lighting apparatus is used to drive a plurality of discharge tubes. The apparatus includes a balance coil having a winding input end and a plurality of winding output ends to which the discharge tubes are connected individually; a power section for supplying ac current to the winding input end of the balance coil; and a control section for detecting a peak value of detection voltages corresponding to voltages at the winding output ends of the balance coil and for stopping the supply of the ac current from the power section when the peak value of the detection voltages is higher than a predetermined value.

Abstract: A power supply circuit for a first and a second lamps and the transformer thereof is provided. The power supply circuit comprises a driving circuit and a transformer. The transformer includes a magnetic core, a primary coil set, a secondary coil, a first coil and a second coil. The driving circuit provides an alternative voltage. The primary coil set is wound on the magnetic core, along with the secondary coil, the first and the second coils, and receives the alternative voltage. The turns of the first coil and the second coil are substantially the same. The first lamp is coupled between the first coil and the secondary coil, and the second lamp is coupled between the second coil and the secondary coil.

Abstract: The invention describes a multiple lamp balance transformer and a drive circuit. The multiple lamp balance transformer has two magnetic cores with a closed magnetic flux path and two coils wound around the closed magnetic flux path. The two coils have the same number of windings. The impedance property of the coil and Lenz's Law are used to balance the operating current of the lamps connected to the coils. The drive circuit has a multiple lamp balance transformer connected to several lamps, and a boost transformer uses a controller to supply the current and voltage to the lamps. A current detect/protect circuit connected to the coils and the controller detects the current passing through the coils and converts the operating current of the lamp into a voltage to be sent to the controller, so that the controller controls and provides sufficient power to the lamps.

Abstract: A lighting system employs a pair of ballast input stages (21) operable to oscillate at different oscillating frequency (f1, f2) upon an initial powering of the ballast input stages (21). The lighting system further employs a pair of ballast output stages (23) for establishing an open circuit voltage across the ballast output stages (23) in response to an absence of a loading of lamps (10) across the ballast output stages (23). The light system further employ means for, subsequent to the initial powering of the ballast input stages (21) and in response to the absence of the loading of the lamps (10) across the ballast output stages (23), impending any parasitic loading across the ballast output stages (23) from phase locking the oscillating frequencies (f1, f2).

Abstract: Switching elements S1, S2 connected in series are provided on the secondary side of a pulse transformer T to which an input voltage is supplied from a DC power supply E. On the primary side of the pulse transformer T, switching element S3, S4 are provided, and a regenerating unit RG including a current limiting inductor L1 and a regenerating inductor L2 is connected to the DC power supply E and the primary side of the pulse transformer T. A current is limited by the inductor L1 during an on time of the element S3 or S4, whilst a current is regeneratively supplied to the DC power supply E by using the inductor L2 during the off time of the elements S3, S4.

Abstract: A power factor correction apparatus with an embedded direct-current to direct-current (DC-DC) converter is provided. The apparatus includes a power factor controller, a high-voltage adapter and a low-voltage adapter. The power factor controller, which receives an AC power source, includes a transformer. The secondary side of the transformer includes a first sub-coil and a second sub-coil for outputting a first power source and a second power source respectively. The high-voltage adapter converts the first power source into a high DC power source. The low-voltage adapter converts the second power source into a first DC power source. The power factor controller corrects the power factor of the power factor correction apparatus according to the first DC power source.

Abstract: The invention relates to a converter circuit with coupled inductances L1 and L2 which have a core K having an air gap S which is asymmetrical with respect to the inductances.

Abstract: An arrangement in connection with a coupling device of a fluorescent lamp, the coupling device comprising a supply transformer, whose secondary is coupled in parallel with a fluorescent tube, the arrangement comprising an indicator circuit configured to indicate the working condition of the fluorescent lamp. The arrangement comprises a signal transformer comprising a first primary coil, to which an alternating voltage signal supply is coupled, a secondary coil, coupled as part of a current path generated by cathodes of the fluorescent lamp and a secondary of the supply transformer and configured to supply alternating current to said current path, the indicator circuit comprising transformer members configured to generate a signal responsive to the alternating current of the current circuit.

Abstract: The present invention achieves the above objects, among others, by providing, in a preferred embodiment, a transformer system for use with either a dimmer switch or an on/off switch, including: a transformer; a load connected to the transformer; a first tap connected to the transformer to provide a first voltage; and a second tap connected to the transformer to provide a second voltage higher than the first voltage. A method of using the transformer system is also provided.

Abstract: The invention relates to an electronic ballast for a dielectrically impeded discharge lamp (L), which ballast has an inductor (W1, W2, W3) with a winding (W2) that can be short-circuited.

Abstract: A ballast for electrical lighting fixtures with improved thermal protection features has ballast laminations, primary and secondary coils, and a thermal protector, the thermal protector being wired in series with the secondary coil. The ballast preferably is of the type having multiple input voltage taps on the primary coil; in such cases, the electrical positioning of the thermal protector in series with the secondary coil causes the wiring assembly of the thermal protector (as part of the ballast) to be independent of the primary coil input voltage tap used in a particular application. Improved electrical lighting circuits for high-intensity-discharge lamps have the above-described thermally-protected ballasts.

Abstract: To efficiently and cost-effectively produce a light source, a CCFL circuit can include a PMOS transistor, first and second NMOS transistors, and a high turns ratio transformer. The transformer can include a primary coil having a center tap, thereby forming first and second primary windings, as well as a secondary coil. The PMOS transistor can be connected to the center tap for driving the transformer. The first and second NMOS transistors can be connected to the first and second primary windings, respectively. Of importance, the first primary winding is tightly coupled to the second primary winding, whereas the first and second primary windings are loosely coupled to the secondary coil.

Abstract: A ballast circuit includes an output isolation transformer having a primary winding and first and second secondary terminals coupled to opposing ballast lamp terminals for additively applying potentials on the primary winding and the first and second secondary winding potentials across the lamp and limiting ground fault voltages. The circuit can include a closed loop feedback path from a load to a feedback rectifier for promoting linear operation of an input rectifier.

Abstract: The invention concerns a method for powering a discharge lamp with a switching power supply. Said method is characterised in that it consists in: applying a voltage firing the lamp, then after the lamp has been energized, applying a lower service voltage to the firing voltage. The firing and service voltages can be generated by using a resonant circuit at the terminals of which a chopped voltage is applied with different frequencies. The invention also concerns a light source comprising a discharge lamp and a switching power supply. Said light source can be equipped with devices for measuring several parameters, such as power, light intensity or the amplitude of vibrations. The invention is useful for producing public lighting.

Abstract: A constant-current regulator for high-powered airport lighting loops combined a ferroresonant transformer and a digital programmable logic device to provide a versatile, software-modifiable current control for power transfer throughout a range of about 30 kW to 50 kW with uniformly good power factor and low harmonics without switching winding taps, and without requiring oil cooling.

Abstract: An integrated filter with both common-mode and differential-mode functions is disclosed. The integrated filter comprises a magnetic core, two windings and a frame for installing the windings. The magnetic core further comprises a rectangular core and an I-shaped core. The frame is fixed to a column of the rectangular core. These two windings are wound on the frame. The I-core is placed across an interior opening of the rectangular core and between these two windings. One integrated filter with a magnetic core composed of a &thgr;-shaped core and an I-shaped core is also disclosed. In addition, the magnetic core may comprise a &thgr;-shaped core and an E-shaped core. The E-core is placed across an interior opening of the &thgr;-shaped core or upright on the &thgr;-shaped core and between these two windings. One integrated filter with a magnetic core composed of a rectangular core and an E-shaped core is also disclosed.

Abstract: A driving apparatus of a discharge tube lamp includes a voltage source; a plurality of AC conversion circuits for boosting a voltage supplied from the voltage source and generating a plurality of boosted AC signals; a plurality of discharge tubes for receiving the boosted AC signals and emitting a plurality of lights; a plurality of detection circuits arranged between each of the plurality of AC conversion circuits and a ground voltage source for detecting a voltage supplied to each of the plurality of discharge tubes; and a controller arranged between the voltage source and each of the plurality of the AC conversion circuits for controlling the voltage supplied to the plurality of AC conversion circuits in accordance with a plurality of detection signals supplied from the plurality of detection circuits.

Abstract: A power saver for discharge lamps, in which supply of electricity is not stopped instantaneously even though applied voltage is converted into lower voltage after lighting the discharge lamp, is disclosed. The power saver for discharge lamps includes a first coil, a second coil having a winding direction opposed to a winding direction of the first coil and located in an opposite direction of the first coil, an insulator located at a gap part where the first coil and the second coil are opposed, at least one or more taps arranged along a longitudinal direction of the second coil, at least one or more switches selectively connected to one of the taps, at least one or more first timers connected to the switches respectively, an electric relay mounted in a loop circuit including both end parts of the second coil, and a second timer connected to the electric relay.

Abstract: A constant-current regulator for high-powered airport lighting loops combined a ferroresonant transformer and a digital programmable logic device to provide a versatile, software-modifiable current control for power transfer throughout a range of about 30 kW to 50 kW with uniformly good power factor and low harmonics without switching winding taps, and without requiring oil cooling.

Abstract: A dimmable electrodeless light source includes an electrodeless lamp, an electronic ballast and a dimming module. The light source further includes coupling transformers coupled to the electrodeless lamp for inductively coupling power to the lamp to generate light. An auxiliary winding electromagnetically coupled to the primary winding of at least one of the coupling transformers is driven by switching circuitry in the dimming module. The switching circuitry is pulse width modulated to control the average brightness of the light generated by the electrodeless lamp. An exemplary application for the dimmable electrodeless light source is as a backlight for a video display device, such as a liquid crystal display unit. The dimmable electrodeless light source further includes a magnetic shield device that is operably positioned with respect to the electrodeless lamp.

Abstract: A description is given of a method for dimming discharge lamps with dielectrically impeded discharges. A continuous or discontinuous power control can be effected by influencing an electric parameter of a pulsed active-power supply and by means of a suitable electrode structure.

Abstract: A white light-emitting-diode array driver circuit with a multiple output flyback (or forward) converter with output current mode control. The circuit comprises a power supply source and a transformer. The transformer has a primary winding coupled to, and configured to receive current from, the power supply, and a plurality of secondary windings coupled to the primary winding. The circuit also comprises a plurality of light-emitting-diode arrays, wherein each light-emitting-diode array is coupled to one of the secondary windings. A main controller is coupled to a first of the light-emitting-diode arrays and is configured to control a flow of current to the primary transformer winding. The circuit also comprises a plurality of secondary controllers, each of which are coupled to another of the light-emitting-diode arrays. In addition, each of the secondary controllers are configured to control a flow of current to its corresponding light-emitting-diode array.

Abstract: In a discharge lamp lighting circuit 1 using a common starter circuit 5A to a plurality of discharge lamps 6i (i=1, 2, . . . , n) to start the discharge lamps 6, the starter circuit 5A has a transformer 7 comprising a plurality of secondary windings 7bi (i=1, 2, . . . , n) provided for a primary winding 7a. A primary circuit 8 comprises a capacitor 9 and a switch element 10 and the generated voltage when the capacitor 9 is charged when the switch element 10 conducts is increased by the transformer 7, then is applied through each secondary winding to the corresponding discharge lamp.

Abstract: A power-factor correction circuit of an electronic ballast for fluorescent lamps which includes an input full-wave rectification circuit for full-wave rectifying an AC input voltage from an AC input power source, a DC-link capacitor for supplying a DC-link voltage in response to an output voltage from the rectification circuit and a resonant inverter connected in parallel to the DC-link capacitor. The power-factor correction circuit comprises a charge pumping circuit disposed between the AC input power source and the rectification circuit, a valley-fill DC voltage supply circuit disposed between the rectification circuit and the DC-link capacitor, and a high-frequency full-wave rectification circuit disposed between the DC voltage supply circuit and the DC-link capacitor and connected to a secondary winding of a power transformer in the resonant inverter.

Abstract: A dimmable electrodeless light source includes an electrodeless lamp, an electronic ballast and a dimming module. The light source further includes coupling transformers coupled to the electrodeless lamp for inductively coupling power to the lamp to generate light. An auxiliary winding electromagnetically coupled to the primary winding of at least one of the coupling transformers is driven by switching circuitry in the dimming module. The switching circuitry is pulse width modulated to control the average brightness of the light generated by the electrodeless lamp. An exemplary application for the dimmable electrodeless light source is as a backlight for a video display device, such as an liquid crystal display unit.

Abstract: A method of winding a step-up transformer substantially minimizes the parasitic capacitance effects between the primary coil of the transformer and the secondary coil of the transformer. The primary coil is wound around a sectional bobbin and laid upon the bobbin in a winding direction that is opposite to the winding direction of the secondary coil. The opposite winding directions allow the high-voltage terminal ends of the primary and secondary coils to be maximally separated. The maximal separation of high-voltage signals within each coil reduces the effects of the capacitive coupling between the coils, and also maximizes the breakdown voltage between the coils. In a preferred embodiment, the auxiliary coil of the step-up transformer is also configured to minimize the effects of capacitive coupling and to maximize the breakdown voltage among the coils.

Abstract: A high frequency control circuit for a gaseous discharge lamp which includes a mechanically variable reactance device coupled in series with the lamp to control the current fed to the lamp. The mechanically variable reactance device is adjustable by a user to alter the intensity of the light emitted by the lamp.

Abstract: An electronic stabilizer with single stage conversion includes a push-pull resonant stage, a synchronous pulse width modulation controller, and a converter. The push-pull resonant stage includes a high frequency transformer and transistors to form an alternating voltage-increasing loop that operates under self-activating oscillation, the high frequency transformer including a secondary winding for driving a lamp. The synchronous pulse width modulation controller samples signals from the lamp and feeds back to control a power input for the lamp. The converter includes transistors to form a dynamic resistance that allows current to flow in both directions. The converter includes an input end that is electrically connected to an output end of the synchronous pulse width modulation controller. The converter further includes an output end that is electrically connected in series to the secondary winding of the high frequency transformer and in series connection with the lamp.

Abstract: A circuit arrangement for operating at least one high-pressure discharge lamp with a high-frequency alternating voltage, the circuit arrangement having a voltage converter (W) with an alternating voltage output (j10, j11), a load circuit which is connected to the alternating voltage output (j10, j11) and which has at least one lamp inductor (L1), a coupling capacitor (C1) and terminals (j12, j13) for at least one high-pressure discharge lamp (LP), and a starter (Z) with a high-voltage source and a high-voltage DC output (j14, j15) for starting a gas discharge in the at least one high-pressure discharge lamp (LP). The coupling capacitor (C1) is connected to the high-voltage DC output (j14, j15) via a charging resistor (R1).

Abstract: A circuit arrangement for igniting and operating an electrodeless discharge lamp provided with a half-bridge commutator having two switching elements each having an emitter electrode and a control electrode and a parasitic capacitance in between. Each switching element is alternately switched to a conducting state by means of a resonant control circuit. The resonant control circuit is coupled to an oscillator by way of a transformer. The resonant circuit is provided with a capacitor which forms a part of the oscillator.

Abstract: A device for lighting a discharge lamp comprises a rectifier, a switching circuit having a semiconductor element to be connected to said rectifier; a direct power supplying circuit having a rectifying circuit and filtering circuit each connected to said switching circuit; and a discharge lamp and a starter which are connected after said filtering circuit; said starter having a transformer and a smoothing capacitor for generating a high voltage is provided, which has a circuit having a switching element and a resistance connected in series provided between the smoothing capacitor and said discharge lamp and further has a second capacitor connected parallel to said discharge lamp.

Abstract: Electronic ballast system for fluorescent lights. A power oscillator connected to the primary winding of a power transformer for operation at a predetermined frequency in the range of 10 KHz to 5 MHz, and a ballasting network is connected to the secondary winding of the transformer and to one or more fluorescent lamps. The ballasting network is resonant at a frequency within about .+-.10 percent of the predetermined frequency, and in some embodiments, the resonant frequency of the ballasting network remains the same regardless of the number of lamps connected to it.

Abstract: In an inverter apparatus for a fluorescent lamp which is used as an original exposure lamp of a copy machine, a first secondary winding to which a choking coil and the fluorescent lamp are connected in series and a second secondary winding to which a capacitor is connected in series are formed on a secondary side of an inverter transducer, and a switching element for switching whether the first and second secondary windings are connected in series or in parallel and a diode bridge are further provided.

Abstract: The invention relates to circuitry for the operation of a high-pressure dharge lamp including a voltage transformer (T1, T2), preferably a push-pull transformer, a transformer (TR1) connected to the output of the voltage transformer (T1, T2), a pulse ignition device, and a load circuit designed as a ocrial resonance circuit (L1, C1) into which the high-pressure discharge lamp (LP) is switched. The transformer (TR1) possesses at least two secondary windings (w1c, w1d), wherein the first secondary winding (w1c) switches into the load circuit and the second secondary winding (w1d) is connected to the pulse ignition device at the voltage input. The ignition voltage output of the pulse ignition device is designed to be connected to an auxiliary ignition electrode (ZE) of the high-pressure discharge lamp (LP).

Abstract: A power source device includes a high frequency power source having a pair of switching elements and converting a DC voltage into an AC high frequency voltage to be supplied to a load, a driving transformer having, wound on a magnetic core, a primary winding and a pair of secondary windings connected respectively in series to each of control terminals of the pair of the switching elements, and a driving device for driving the two switching elements by applying a voltage to the primary winding of the driving transformer. The secondary windings are wound on the core to be separated in every turn at equal intervals and not to be intimately close to each other, for remarkable improvement in the degree of variability in the efficiency of circuit forming the power source device.

Abstract: A first intermediate direct voltage is generated from a current source or board voltage, and a second sinusoidal intermediate alternating voltage is generated with a current inverter. This intermediate alternating voltage is transformed by one or more transfer systems to the various triggering and maintaining voltages of different cold cathode discharge lamps. Frequency-synchronous dimming is regulated by the pulse-pause ratio of a pulse group regulator in a broad frame by optically commanded triacs which are triggered in the zero crossing. The preconditions for the starting and maintenance characteristics of the lamps are thus always ensured.

Abstract: For driving gas discharge lamps, a ballast is provided between the positive and the negative output terminals of a rectifier arrangement (D1, D2, D3, D4). The ballast comprises a filter stage (C1, C2, C3, DR1, DR2) with an oscillation voltage build-up circuit (R1, C6, D5, DIAC) and with a high-frequency resonant circuit (R2-R6, T1, T2, D5, D6, C6, I1, I2), and also with a decoupling capacitor (C7), a third inductor (DR3) and a third inductance (I3, I4). This third inductance is wound together with the two abovementioned windings of the high-frequency resonant circuit (I1, I2) onto a common core. The ballast is routed by a connecting line (VL) from the junction (H) between the two transistors (T1, T2) to one electrode (E1) of the discharge lamp (FL), the second electrode (E2) of which is connected to the first electrode (E1) via a resonant capacitance (C12, C13).