Abstract: The present invention provides a low-cost inverter for ballast. A current transformer is connected in series with a lamp to operate the lamp. A first transistor and a second transistor are coupled to switch the resonant circuit. The current transformer is utilized to generating control signals in response to the switching current of the resonant circuit. The transistor is turned on once the control signal is higher than a first threshold. After that, the transistor is turned off once the control signal is lower than a second threshold. Therefore, a soft switching operation for the first transistor and the second transistor can be achieved.

Abstract: A power system for driving plural or multiple lamps includes a transformer circuit, a filter and steady-flow circuit, and a light source. The transformer circuit transforms a voltage level of an input AC signal, and includes a first output end for outputting a first AC signal, and a second output end for outputting a second AC signal. The first and second AC signals are opposite in phase. The filter and steady-flow circuit includes a first plurality of filter and steady-flow units connected to the first output end for suppressing harmonic signals of the first AC signal and outputting a plurality of third AC signals. The light source has a first plurality of lamps, each of which having one end connected to one of a respective one of the first plurality of filter and steady-flow units so as to be driven by a respective one of the third AC signals.

Abstract: A lamp driver circuit is disclosed. The lamp driver circuit comprises a passive power factor correction (PFC) circuit. The passive PFC circuit, in operation, is coupled with an alternating-current (AC) power source. The lamp driver circuit further includes a direct-current to direct-current (DC-DC) power converter coupled with the passive PFC circuit. The DC-DC power converter, in conjunction with the passive PFC circuit, operates as a constant energy converter. The lamp driver circuit also includes a lamp circuit coupled with the DC-DC power converter.

Abstract: A low voltage lighting system includes a transformer having at least a primary winding and a secondary winding. The low voltage lighting system also includes one or more lighting elements and a voltage control circuit. The lighting elements are coupled to the secondary winding. The voltage control circuit is electrically coupled with the primary winding. The voltage control circuit is configured to automatically increase the voltage applied to the primary winding of the transformer in a predetermined manner from a first voltage to a second voltage over a predetermined period of time.

Abstract: The invention provides a power supply or drive circuit for a pulsed flashlamp which utilizes a two-core component having common windings as both an inductor for arc mode drive and for breakdown triggering of the lamp. Discharge of a capacitor through the inductor and lamp is controlled by a high-speed semiconductor switch which is turned on and off by a suitable control, current flowing from the inductor through a one-way path including the lamp when the switch is off. The control maintains the ratio of the power variation through the lamp to the average power through the lamp substantially constant. The controls may also be utilized to control output pulse shape. Novel protective features are also provided for circuit components during turn on periods for the switch.

Abstract: A power transformer combined with balance windings is used for driving a CCFL. The power transformer makes use of a ferrite core structure to achieve a closed magnetic circuit, and is combined with balance windings. When used in application circuits, the power transformer combined with balance windings can provide stable induction voltages and balance load currents to CCFLs to enhance the luminous efficiency and uniformity of the CCFLs, thereby improving the drawbacks of a irregular current flowing through the CCFLs and too high a manufacturing cost of conventional CCFL application circuits.

Abstract: A driving device for driving a light source module (32) includes a first power stage circuit (30) and a first transformer circuit (31). The first transformer circuit is connected to the first power stage circuit, including a first transformer (T31), a second transformer (T32), a third transformer (T33), and a fourth transformer (T34). First inputs of primary windings of the first transformer and the fourth transformer, second inputs of primary windings of the second transformer and the third transformer are jointly connected to a positive output of the first power stage circuit, and second inputs of primary windings of the first transformer and the fourth transformer, first inputs of primary windings of the second transformer and the third transformer are jointly connected to a negative output of the first power stage circuit.

Abstract: A driving device for driving a light source module (47) includes a PFC circuit (42), a power stage circuit (44), an isolation transformer (T1), an inverter circuit (45) and a PWM controller (46). The PFC circuit converts a received AC signal to a DC signal. The power stage circuit is connected to the PFC circuit, for converting the DC signal to another AC signal. The isolation transformer has a primary winding and at least one secondary winding. The primary winding of the isolation transformer is connected to the power stage circuit, for isolating the received AC signal from the light source module. The inverter circuit is connected to the secondary winding of the isolation transformer, for converting an AC signal output from the isolation transformer to an appropriate signal. The PWM controller is connected to the power stage circuit, for controlling output from the power stage circuit.

Abstract: A small balancer coil for cold-cathode florescent lamps having sufficient shunt/balance effects, comprises a discharge lamp, a conductor located close to the discharge lamp, and two coils whose magnetic fluxes face each other. The magnetic fluxes generated in the coils face and cancel each other. Lamp currents of the discharge lamps are balanced by making the sum of the reactances of the mutual inductance of the balancer coil larger than the negative resistance of the discharge lamp. Section winding is applied to each coil of the balancer coil so as to maintain shunt and balance effects even in a small/flat balancer coil by making self-resonance frequency of each of the coils higher.

Abstract: A ballast (20) for powering one or more gas discharge lamps (70,72,74,76) comprises an inverter (200), an output circuit (300), and an arc protection circuit (400). Arc protection circuit (400) monitors an electrical signal within the output circuit (300). When an arcing condition occurs at the ballast output connections (302,304,306,308,310), the electrical signal includes a high frequency component having a fundamental frequency that is much greater than the normal operating frequency of the inverter (200). In response to the high frequency component exceeding a predetermined threshold, arc protection circuit (400) disables the inverter (200) for a predetermined shutdown period. Arc protection circuit (400) also provides a restart function for periodically attempting to ignite and operate the lamps.

Abstract: A cold cathode tube lighting device is provided which is capable of achieving stable luminance when driven by applying driving pulses to input terminals on both sides of each of two or more cold cathode tubes. Each of currents flowing through coils in each of coil units on both sides of each of two or more cold cathode tubes is detected by voltage detecting sections and a tube current flowing through each of the cold cathode tubes based on a value obtained by adding each of the currents using an adder and a duty ratio of each of driving pulses is controlled so that the tube current becomes a specified current value to keep the luminance of the cold cathode tubes constant.

Abstract: In one aspect, an impedance component which exhibits a high impedance in a high frequency region is arranged on a high pressure line formed on a secondary side of a transformer. The potential difference generated at both ends of the impedance component is used to detect an abnormal electrical discharge generated in the high pressure line. When the abnormal electrical discharge is detected, a switching operation is stopped by a controlling circuit, whereby a protection operation is performed.

Abstract: A driver circuit provides electrical energy from a power source to a fluorescent lamp such as that used in a flat-panel or other liquid crystal display (LCD). The circuit includes a transformer having a primary winding and a secondary winding, with the ends of the secondary winding coupled to the fluorescent lamp. A first switch switchably provides a drive output signal to the transformer based upon a switch input signal. A current control loop adjusts the switch input in response to the current in one of the windings of the transformer, and a luminance control loop adjusts the switch input in response to the brightness of the light. A lamp current frequency control loop adjusts the polarity of the primary winding in response to a signal received from the transformer to thereby adjust the frequency of the lamp drive current applied to the fluorescent lamp.

Abstract: A CCFL (cold-cathode fluorescent lamp) driving system for digitally driving at least one CCFL, according to embodiments of the present invention, generally includes a transformer, a sense circuit and a CCFL controller. Through the transformer, a DC voltage is supplied to the CCFL load. The sense circuit is provided to sense the current flowing through the CCFL load, and generate a corresponding feedback signal as an input to the CCFL controller. In accordance with embodiments, the CCFL controller is provided to receive a triangular waveform signal and a sinusoidal waveform signal, where the sinusoidal waveform signal has an amplitude regulated by the feedback signal and generate an output signal, corresponding to a comparison of said triangular waveform signal and the amplitude-regulated sinusoidal waveform signal, thus the output signal can be utilized to regulate the voltage delivered to the CCFL load.

Abstract: In order to suppress leak current at the time of high voltage application to a fluorescent lamp so as to improve the luminous efficiency, the present invention provides a fluorescent lamp driver, which includes switching means that switches a DC power supply voltage, and a first transformer and a second transformer configured to obtain AC voltages each having reverse polarity, as AC voltages excited from primary winding to secondary winding of the respective transformers, on the basis of output voltages of the switching means, in which the first transformer and the second transformer are positioned in the vicinity of both ends of the fluorescent lamp, and the AC voltage obtained in the secondary winding of the first transformer is applied to one terminal of the fluorescent lamp and the AC voltage obtained in the secondary winding of the second transformer is applied to the other terminal of the fluorescent lamp.

Abstract: A driver for HID lamps includes four switches and generates a constant DC-current that is commutated at a low frequency. The driver includes a filter capacitor. The occurrence of peak currents due to the charging or discharging of the filter capacitor is prevented by driving one of the switches at a high frequency immediately after commutation.

Abstract: A discharge lamp lighting control device (100) having a DC power converter, a power factor improving power converter (1), a polarity reversing circuit (2), a starter circuit (3), and a controller (4). The power factor improving power converter 1 includes a switching device S, a power factor improver, and a power converter. The power factor improver operates to smooth a rectified voltage by storing energy in a first inductive device L1 and by discharging energy from a second inductive device L2, in which the first and second inductive devices are magnetically coupled together. The storing and discharging is performed by turning ON and OFF the switching device S. A predetermined DC voltage is converted by energy stored and discharged by a third inductive device L3 in response to the turning ON and OFF of the switching device S.

Abstract: A circuit includes a transformer 7 for transmitting power to a discharge lamp 10 and for supplying a starting signal to the discharge lamp. The circuit includes a direct current-alternating current converting circuit 3 for supplying an output of the transformer 7 to the discharge lamp 10 after carrying out a direct current-alternating current conversion, and a starting circuit 4 for applying the starting signal to the discharge lamp 10. A primary side of the transformer 7 has a first capacitor 11, a circuit portion 13 including a rectifying element, and a switching element 14. The transformer 7 has an auxiliary winding 7v for supplying a voltage for generating the starting signal to the starting circuit. A second capacitor 12 is interposed between the auxiliary winding and the circuit portion 13 and prevents absorption of energy by the capacitor 11 in generating the starting signal and prevents attenuation of the starting signal.

Abstract: A lamp, a method of driving the lamp, a backlight assembly having the lamp, and a liquid crystal display (LCD) device having the backlight assembly are disclosed. The lamp includes a tube that contains gas and first through fourth electrodes. The first and second electrodes are disposed in the tube adjacent to first and second ends of the tube. The third and fourth electrodes are disposed at the first and second ends of the tube. Voltages applied to the electrodes are sufficient for light to be emitted throughout the lamp. The first and second voltages, third and fourth voltages, first and third voltages, and second and fourth voltages have different polarities while the first and fourth voltages and the second and third voltages have the same polarity.

Abstract: A driving device is provided, which includes: a switching unit directly connected to a first voltage from a source external to the driving device; a transforming unit indirectly connected to the switching unit for transforming the first voltage into a second voltage and applying the second voltage to a light source; a signal transmitting unit indirectly connected to the switching unit and transmitting a driving voltage for driving the switching unit based on a control signal; and an inverter controller outputting the control signal to the signal transmitting unit.

Abstract: A driving device for driving a light source module (47) includes a PFC circuit (42), a power stage circuit (44), an isolation transformer (T1), an inverter circuit (45) and a PWM controller (46). The PFC circuit converts a received AC signal to a DC signal. The power stage circuit is connected to the PFC circuit, for converting the DC signal to another AC signal. The isolation transformer has a primary winding and at least one secondary winding. The primary winding of the isolation transformer is connected to the power stage circuit, for isolating the received AC signal from the light source module. The inverter circuit is connected to the secondary winding of the isolation transformer, for converting an AC signal output from the isolation transformer to an appropriate signal. The PWM controller is connected to the power stage circuit, for controlling output from the power stage circuit.

Abstract: A master-slave control architecture for inverters includes a master control circuit board which has a master control unit to output a plurality of frequency signals of the same phase and same frequency so that driving units on a plurality of separated slave control circuit boards on the rear end can be driven synchronously by the frequency signals to control electricity input of transformation units to transform voltage for outputting. Thereby the frequency of the driving electricity of the discharge lamps can be synchronized to maintain uniform luminance.

Abstract: An electronic device for starting and/or re-starting a power-driven device such as a lamp, bulb or lighting fixture includes an input stage, a rectifier stage, a power factor correction stage with total harmonic distortion correction, and a coil device comprising a wound coil having a primary winding of multistranded wire. The circuit may automatically adjust to a range of loads, and/or it may provide an auto-ranging line voltage. In an embodiment, the input stage accepts an AC input signal, the rectifier stage converts the AC input signal to a DC signal, and the coil device converts the DC signal to an AC output signal. The device may also include a frequency adjustment circuit that adjusts the frequency of the AC output signal to assistance in the performance of a restart function.

Abstract: A circuit such as may be used for igniting and operating a gas discharge lamp is provided. The circuit includes a resonant circuit connected to receive a variable voltage output signal from an inverter. The resonant circuit includes a first circuit stage and a second circuit stage. The second circuit stage includes a resonant tank circuit configured to generate a resonant output voltage when a switching frequency of the inverter matches a resonant frequency of the resonant circuit. The first circuit stage includes at least one current-suppressing element for reducing an effect of a resonant current that flows in the resonant circuit on a switching current that flows in the inverter.

Abstract: A portable fluorescent task lamp comprising at least two fluorescent bulbs of any wattage up to forty Watts and of either a non-starting type or a self-starting type; and an electronic ballast circuit for use therewith including an SPST function switch disposed in series with each fluorescent bulb, wherein the fluorescent bulbs may be ignited and sustained in illumination in parallel, simultaneously or individually, as determined by the respective SPST switches.

Abstract: The present discharge lamp lighting device is capable of rapid modulation in which a lamp current is rapidly reduced and rapidly restored. The current control circuit is provided to perform specific current control such that the brightness of a lamp is reduced by a predetermined percentage without being affected by a variation or change in lamp voltage over time, thereby reducing a lamp current.

Abstract: To provide a discharge lamp ignition device to light high-intensity discharge lamps in which, during alternating current ignition, the fluctuation of luminous flux on the reversal of polarity of the voltage impressed on the lamp is minimized and in which steady lighting characteristics of the discharge at startup are secured, a discharge lamp ignition device has a capacitor Ch connected to a transformer Th and an intermittent voltage impression arrangement Uj to drive voltage impression on the primary winding Ph, with the secondary winding Sh of the transformer Th constituted so that the voltage generated in the secondary winding Sh can be impressed overlapping the output voltage of an inverter Ui between the electrodes of the discharge lamp Ld by interposing it in the path connecting the output of the inverter Ui and the electrode for the main discharge of the discharge lamp Ld.

Abstract: A backlight driving and control circuit with an isolated power factor correction structure includes a power stage for providing a power supply; a driver stage having a first power factor correction unit for correcting the power factor of the power supply and outputting DC power; an inverter for converting a middle-voltage DC power into a high-voltage power output and driving the operation of a backlight light emitting component; and a control/dimming stage having a second power factor correction unit, a DC transformer unit, and an AD board installed at a secondary winding of the DC transformer unit and grounded jointly with the inverter. With the invention, the power factor correction unit can be electrically isolated from the power stage, and the AD board can directly control/dim the inverter of the driver stage to change the operating status of the backlight light emitting component.

Abstract: The present invention relates to a circuit arrangement for operating at least one electric lamp (LP) having a drive circuit (16), which has at least one terminal for a system voltage (UN) on the input side and at least one terminal for the at least one electric lamp (LP) on the output side; the drive circuit (16) having a control unit (18) and a step-up converter having a step-up converter inductor (L2) and a switch (S1), and the control unit (18) being designed to operate the step-up converter in a discontinuous mode, in which the current (IN) through the step-up converter inductor (L2) has gaps, the duration (?t) of these gaps being varied. It also relates to an operating method for at least one electric lamp (LP) using such a circuit arrangement.

Abstract: A lighting circuit includes a capacitor and inductor for a resonance, and a first output, a second output, a resistor and a monitor circuit. A DC-AC converting circuit generates an AC voltage from a DC voltage. The resistor has an end connected to the second output and the other end connected to an end of a secondary winding. A monitoring output is connected to the other end of the resistor, and is provided for providing a signal for monitoring a current flowing to a discharge lamp. The end of the resistor is connected to a grounding conductor GND. The monitor circuit receives a signal from the monitoring output. The monitor circuit generates a signal for monitoring a current IL flowing to the discharge lamp.

Abstract: A CCFL (cold-cathode fluorescent lamp) driving system for digitally driving at least one CCFL, according to embodiments of the present invention, generally includes a transformer, a sense circuit and a CCFL controller. Through the transformer, a DC voltage is supplied to the CCFL load. The sense circuit is provided to sense the current flowing through the CCFL load, and generate a corresponding feedback signal as an input to the CCFL controller. In accordance with embodiments, the CCFL controller is provided to receive a triangular waveform signal and a sinusoidal waveform signal, where the sinusoidal waveform signal has an amplitude regulated by the feedback signal and generate an output signal, corresponding to a comparison of said triangular waveform signal and the amplitude-regulated sinusoidal waveform signal, thus the output signal can be utilized to regulate the voltage delivered to the CCFL load.

Abstract: Embodiments of a circuit to power an arc lamp are disclosed.

Abstract: A driving device for driving a plurality of lamps each including a first terminal and a second terminal, includes a power stage circuit (202), a transformer circuit (204) electrically connectable to the power stage circuit, and a current balancing circuit (206) to balance current of the lamps. The current balancing circuit includes a plurality of current balancing components each comprising two inputs and two outputs. The number of the current balancing components is defined as n, where n is an integer from 2 to n. The inputs of the first current balancing component are electrically connected to a terminal of the transformer circuit. The inputs of the nth current balancing component are electrically connected to the outputs of the (n?1)th current balancing component. The outputs of each current balancing component are respectively electrically connected to the first terminals of two of the lamps.

Abstract: A multi-lamp driving system includes a driving apparatus and a current balancer having detection nodes. The protection apparatus includes at least a detection unit and a determining unit. The detection unit includes first impedance devices and a second impedance device. A first end of each first impedance device is coupled with the corresponding detection node. The second impedance device is coupled with a second end of each first impedance device. The cross-voltage between a first end and a second end of the second impedance device is relative to the sum of the voltage level of the detection nodes coupled with the first impedance devices. The determining unit coupled with the second impedance device of the detection unit outputs a protection signal to disable the driving apparatus according to the cross-voltage between the first and second ends of the second impedance device when at least one of the lamps malfunctions.

Abstract: Two types of rectangular waves having different numbers of driving pulses are applied to the HID bulb. By changing the combination of these two different types of rectangular waves to be supplied , the driving energy of the HID bulb is increased or decreased, thereby supply electric energy to the HID bulb is controlled accurately.

Abstract: A capacitor charging circuit does not include a Zener diode and makes it possible to integrate a large number of circuits and elements within a semiconductor integrated circuit. The capacitor charging circuit includes a flyback transformer having a primary coil, a secondary coil, and a tertiary coil, a switching element that turns the current that flows through the primary coil on and off, a capacitor that is charged by a current produced in the secondary coil through the on-off action of the switching element, and a charge control circuit that controls the on-off action of the switching element. When the switching element is off and a voltage produced at a first end of the tertiary coil is larger than a reference voltage corresponding to the predetermined voltage of the charge voltage of the capacitor, the on-off action of the switching element is stopped.

Abstract: A lamp module for use in a backlight module of a flat panel display comprises a first transformer, a second transformer, a plurality of first lamps and a plurality of second lamps. The first transformer provides an AC power of a first phase, and the second transformer provides an AC power of a second phase. One end of the first lamp couples to the first transformer and another end couples to a node. One ends of the second lamps couples to the second transformer and another end couples to the node.

Abstract: A discharge-lamp lighting apparatus includes first and second cold cathode fluorescent lamps (CCFLs) and first and second transformers. The first transformer has a primary winding and a secondary winding. The primary winding receives an AC voltage generated by turning on/off a first switching element pair that is connected to a first DC power source. The second transformer has a primary winding, a first secondary winding, and a second secondary winding. The primary winding of the second transformer receives an AC voltage generated by turning on/off a second switching element pair that is connected to a second DC power source. Polarities of the first and second secondary windings of the second transformer are set so that a voltages of each of the first and second secondary windings becomes additive to a voltage of the secondary winding of the first transformer.

Abstract: A discharge-lamp lighting apparatus includes first and second cold cathode fluorescent lamps (CCFLs) and first and second transformers. The second transformer has a primary winding connected in parallel to one of primary and secondary windings of the first transformer, a first secondary winding, and a second secondary winding. Each of the first and second secondary windings of the second transformer is connected to the secondary winding of the first transformer with polarities being set so that a voltage of each secondary winding of the second transformer becomes additive to a voltage of the secondary winding of the first transformer. The first CCFL is connected in parallel to a series circuit that includes the secondary winding of the first transformer and the first secondary winding of the second transformer.

Abstract: Presented is a driving circuit for multiple discharge lamps, including a plurality of transformers having a plurality of primary windings and secondary windings, in which each secondary winding is connected in series with a resonance circuit and each resonance circuit is coupled to a discharge lamp. The driving circuit further includes an additional resonance inductor coupled to the primary side of the transformers for increasing the resonance inductance of the resonance circuit and allowing the resonance inductance of the resonance circuit to be modulated in response to the variation of the impedance of the discharge lamp or the variation of the impedance of the resonance capacitor of the resonance circuit.

Abstract: System and method for driving a cold-cathode fluorescent lamp. The system includes a control subsystem configured to generate one or more control signals, and a power supply subsystem configured to receive the one or more control signals and a DC input voltage, convert the DC input voltage to an AC output voltage, and send the AC output voltage to a cold-cathode fluorescent lamp. If the DC input voltage is lower than a predetermined threshold, the system for driving the cold-cathode fluorescent lamp is turned off in response to the one or more control signals.

Abstract: A backlight device capable of increasing luminance efficiency includes a power transformation device having a primary end and a secondary end for transforming current received by the primary end and outputting transformed current from the secondary end. The backlight device further includes a double-wind coupling element including a first coupling element and a second coupling element coupled to terminals of the secondary end, for adjusting current between the first coupling element and the second coupling element, and a cold cathode fluorescent lamp coupled to the first coupling element and the second coupling element, for making current flowing into the cold cathode fluorescent equal to current flowing out from the cold cathode fluorescent according to adjusted current between the first coupling element and the second coupling element.

Abstract: A ballast (20) for powering one or more gas discharge lamps (70,72,74,76) comprises an inverter (200), an output circuit (300), and an arc protection circuit (400). Arc protection circuit (400) monitors an electrical signal within the output circuit (300). When an arcing condition occurs at the ballast output connections (302,304,306,308,310), the electrical signal includes a high frequency component having a fundamental frequency that is much greater than the normal operating frequency of the inverter (200). In response to the high frequency component exceeding a predetermined threshold, arc protection circuit (400) disables the inverter (200) for a predetermined shutdown period. Arc protection circuit (400) also provides a restart function for periodically attempting to ignite and operate the lamps.

Abstract: A lamp inverter with continuous strike voltage facilitates faster striking of a fluorescent lamp, especially at cold temperatures. A frequency sweep generator sweeps the frequency of the lamp inverter to a striking frequency corresponding to a striking lamp voltage and then maintains the striking frequency until the lamp strikes.

Abstract: The invention provides a power supply or drive circuit for a pulsed flashlamp which utilizes a two-core component having common windings as both an inductor for arc mode drive and for breakdown triggering of the lamp. Discharge of a capacitor through the inductor and lamp is controlled by a high-speed semiconductor switch which is turned on and off by a suitable control, current flowing from the inductor through a one-way path including the lamp when the switch is off. The control maintains the ratio of the power variation through the lamp to the average power through the lamp substantially constant. The controls may also be utilized to control output pulse shape. Novel protective features are also provided for circuit components during turn on periods for the switch.

Abstract: A multi-lamp driver driving first and second lamps and comprising a driving circuit and a transformer. The transformer comprises a winding rack, a magnetic core, two primary winding sets, and two secondary winding sets. One portion of the magnetic core is inserted into the winding rack. The two primary winding sets are wound around the winding rack and receive low-voltage signals from the driving circuit. The two secondary winding sets are wound around the winding rack, and two high-voltage signals are induced to respectively drive the first and second lamps. The primary winding sets have substantially the same number of windings, and the secondary winding sets have substantially the same number of windings.

Abstract: A ballast according to the present invention operates in an ignition state, a warm-up state, and a steady state for igniting and powering a lamp. The ballast comprises an igniter that ignites the lamp during the ignition state and a switching power inverter, for example, a full bridge DC-AC inverter implemented with MOSFET switching transistors, that powers the lamp during the warm-up and steady states. The switching power inverter, which drives the igniter, operates at a first switching frequency during the ignition state and operates at a second switching frequency during the steady state. Preferably, the first switching frequency, which in one exemplary embodiment is in the kHz range, is higher than the second switching frequency.

Abstract: The invention relates to a high-pressure discharge lamp having electrodes arranged inside a discharge vessel which define a discharge path of a gas discharge in the discharge vessel, and having a starting device, arranged inside the lamp base for the high-pressure discharge lamp and designed as a pulse starting device, for starting the gas discharge in the discharge vessel, and having, arranged outside its discharge vessel, an auxiliary starting electrode coupled to the pulse starting device, the voltage input of pulse starting device being connected in parallel with the discharge path of the high-pressure discharge lamp, such that according to the invention the voltage across the discharge path serves as supply voltage for the pulse starting device. Also disclosed is an operating method for such a high-pressure discharge lamp.

Abstract: A lamp current control device includes an electronic power switch, a transformer, a current transformer and a pulse width modulation (PWM) IC. The transformer has its primary side connected to the electronic power switch and a secondary side connected to a lamp. The current transformer is serially connected with the primary side of the transformer. The PWM IC is coupled between a secondary side of the current transformer and the electronic power switch and uses the current transformer to feedback a feed back signal from the primary side of the transformer. The PWM IC receives and processes the feed back signal to obtain a control signal, and then the PWM IC outputs the control signal to the electronic power switch to control a pulse width outputted by the electronic power switch, thereby controlling and maintaining a brightness of the lamp.

Abstract: A method for driving a fluorescent lamp and an inverter circuit for performing the same are used to reduce an amount of electromagnetic interference (EMI) generated by a transformer and an instantaneous loading of a DC voltage source. The inverter circuit comprises a DC square wave voltage source, a bridge DC/AC converter, a transformer, a feedback control unit and a voltage control circuit wherein the voltage control circuit is coupled to the DC voltage source, the bridge DC/AC converter and the feedback control unit. The voltage control circuit is used to convert DC voltage provided by the DC voltage source into a two-level DC square wave, which in turn converts the two-level DC square wave into an AC quasi-sine wave to drive the fluorescent lamp through the bridge DC/AC converter and the transformer. The feedback control unit generates signals to control the voltage control circuit and the bridge DC/AC converter.