Abstract: An electronic converter includes first and second inputs, first and second outputs, and a switching cell configured to supply current. The switching cell includes a half-bridge including first and second switches connected in series between the two inputs. The half-bridge includes a intermediate point between the first and second switch, a first inductor directly connected to the first output, a second inductor connected to the intermediate point, a first capacitor connected in series with the first and second inductors, a second capacitor connected between the intermediate point and the second input, and a circuit connected between a terminal of the first inductor and the second output. A circuit path of the converter is configured to couple the second inductor with the first output through the first capacitor and the first inductor, and another circuit path is configured to couple the second capacitor with the first output through the first inductor.

Abstract: A combination current sensor is disclosed. The combination current sensor includes a self-powering current transformer (CT), comprising a CT core having a CT coil wound therearaound. The CT coil comprises a predetermined number of individual turns of a conductive wire wound progressively along a length of the CT core to define a winding density, wherein the winding density of the CT coil varies along the length of the CT coil core. The combination current sensor also includes a Rogowski current sensing transformer, which includes a Rogowski core and a Rogowski coil wound therearound.

Abstract: An RF fluorescent lamp comprising an electric ballast comprising an inverter circuit operating at a first frequency that provides the voltage and current with reference to local ground to a switching node connected to a first end of a winding of a power coupler, a timing circuit operating at a second frequency equal to or less than half the first frequency, and an enable circuit activated by the timing circuit that enables and disables the inverter circuit.

Abstract: A replacement smart relay having a relay, controlled by a microcontroller operably connected through a power line communication line that receives instructions from a relay controller, the relay has a simulated resistor representative of a reference resistance, the instructions pass through commands that are sent to the relay control terminals to the relay switched terminals to allow the relay to function the same as the relay it is replacing in the existing application, the instructions from the relay controller are capable of opening or closing the relay switched terminals to override a command on the relay control terminals from the existing application based on a set of vehicle conditions communicated to the relay controller, and instructions from the relay controller allow the smart relay to act deterministically when the smart relay is not actively communicating with the relay controller. A feedback circuit may be used to enhance functionality.

Abstract: A method for inspecting an insulator for a spark plug to determine whether or not the insulator has a defect, the spark plug extending in an axial direction, includes a voltage applying step of applying a voltage between a first electrode disposed in an axial hole in the insulator and a second electrode disposed near an outer peripheral surface of the insulator. The voltage applying step is performed while a gap between a front end of the first electrode and an inner peripheral surface of the insulator that faces the front end of the first electrode in a radial direction is filled with a first insulating material without leaving a hollow space.

Abstract: The invention relates to a LED light source comprising: input terminals (K1, K2) for connection to a mains voltage supply source, a rectifier (RB) coupled to the input terminals for rectifying the mains supply voltage supplied by the mains supply voltage source and comprising rectifier output terminals, a DC-DC converter (CONV) for generating a DC current out of the rectified mains supply voltage, comprising converter input terminals connected to the rectifier output terminals and comprising a first converter output terminal (A) and a second converter output terminal (B), —a LED load (LL) with an anode coupled to the first converter output terminal via a current control element (D5) for blocking a current flowing from the anode of the LED load to the first converter output terminal, and with a cathode coupled to the second converter output terminal via a first controllable switch (M1) having a control electrode coupled to first control circuitry for rendering the controllable switch non-conductive in case the

Abstract: An implantable medical device includes a low-power circuit, a high-power circuit, and a dual-cell power source. The power source is coupled to a transformer having first and second primary windings, each of which is selectively coupled to the power source and a plurality of secondary windings that are magnetically coupled to the first and second primary windings. The plurality of secondary windings are interlaced along a length of each of the secondary windings. Each of the plurality of secondary transformer windings is coupled to a capacitor, and the capacitors are all connected in a series configuration. The low power circuit is coupled to the power source and issues a control signal to control the delivery of charge from the power source to the plurality of capacitors through the first and second transformers.

Abstract: The invention provides an LED converter for operating a load comprising at least one LED series with at least one LED, preferably with multiple LEDs, wherein the LED converter on the primary side comprises a resonant converter supplied with a direct current voltage. Said converter has a half-bridge constructed of two reciprocally clocked switches and providing a supply voltage for the LED series through a serial/parallel resonance circuit connected to the midpoint of said bridge. The LED converter has a control unit that is arranged for adjusting the clocking frequency of the half bridge.

Abstract: A chip capacitor according to the present invention includes a substrate, a pair of external electrodes formed on the substrate, a capacitor element connected between the pair of external electrodes, and a bidirectional diode connected between the pair of external electrodes and in parallel to the capacitor element. Also, a circuit assembly according to the present invention includes the chip capacitor according to the present invention and a mounting substrate having lands, soldered to the external electrodes, on a mounting surface facing a front surface of the substrate.

Abstract: A drive and control circuit for motor system and the method thereof are disclosed. The motor system could be applied in a cooling device, wherein the motor system comprises a rotor, a coil and a bridge circuit. The drive and control circuit comprises a control unit, a state detecting circuit, a load determining circuit, and a startup setting circuit. The startup setting circuit makes the motor run with the maximum torque, thus to make the motor system start up easily and quickly. The load determining circuit detects the load of the motor system, thus to generate a load determining signal to determine the speed of the motor system. The control unit could be realized with few components so as to save the costs.

Abstract: A resonant DC-DC converter used to drive an LED array includes a half-bridge converter configured to receive DC input power and produce a square wave voltage. A resonant tank circuit that includes an inductive element, a first resonance capacitor, and a second resonance capacitor, is coupled to the half-bridge converter to receive the square wave voltage such that a generally sinusoidal AC voltage is produced across the second resonance capacitor. An output transformer with a primary winding and one or more secondary windings, is coupled in parallel to the second resonance capacitor, and a clipping circuit is coupled to the primary winding such that the voltage across the primary winding does not substantially exceed the voltage of the DC input power. An output rectifier is coupled to the one or more secondary windings of the output transformer and is configured to produce a generally DC output voltage.

Abstract: An apparatus for setting a digital setpoint for a self-powered current sensing switch includes a current transformer, a digital processor and a parallel converter for converting the AC output of the current transformer to a DC power source for the digital processor along a first path and into a digital signal which is input to the digital processor along a second path. The apparatus also includes a manually operated switch coupled to the digital processor and having a calibration mode position, code segments executing on the digital processor to convert the digital signal to a digital setpoint value when the manually operated switch is in the calibration mode position, and non-volatile memory for storing the digital setpoint value.

Abstract: A ballast circuit is disclosed for inductively providing power to a load. The ballast circuit includes an oscillator, a driver, a switching circuit, a resonant tank circuit and a current sensing circuit. The current sensing circuit provides a current feedback signal to the oscillator that is representative of the current in the resonant tank circuit. The current feedback signal drives the frequency of the ballast circuit causing the ballast circuit to seek resonance. The ballast circuit preferably includes a current limit circuit that is inductively coupled to the resonant tank circuit. The current limit circuit disables the ballast circuit when the current in the ballast circuit exceeds a predetermined threshold or falls outside a predetermined range.

Abstract: An emergency lighting system induces an AC current in a toroidal coil encircling a non-shielded electrical element of a power circuit. The AC current is rectified to DC and delivered to a rechargeable standby battery. The battery provides a first input to a NAND gate, and a proximity transducer provides a second input to the NAND gate. When the power circuit is energized from the power grid, both inputs to the NAND gate are high and the output is low. When no current is sensed by the transducer one of the input NAND gates is low so that the NAND gate output is high thereby delivering an illumination current to an emergency lighting LED either directly or through a boost amplifier.

Abstract: A control circuit of a light-emitting element comprises a rectifying unit (30), a switching element (38), a transformer (48) having a first winding (L1) which generates a magnetic field using a current controlled by switching of the switching element (38), a second winding (L2) which is magnetically coupled to the first winding (L1) and which generates a current flowing to an LED (102), and a third winding (L3) which is magnetically coupled to the first winding (L1) and which generates a voltage (Sfbk), and an averaging capacitor (32) which averages a voltage derived by superposing a voltage (Srec) rectified by the rectifying unit (30) and the voltage (Sfbk), and a voltage averaged by the averaging capacitor (32) is applied to the first winding (L1), so that light is emitted from the LED (102).

Abstract: Provided is a multi-channel LED driver circuit, including a power supply device for providing an independent voltage source; a plurality of regulating circuits connected to the power supply device and the light light-emitting diode arrays for receiving a voltage from the voltage source and providing a plurality of output currents to the light-emitting diode arrays, and thereby generating a plurality of error signals.

Abstract: In one embodiment, a self-oscillating electronic ballast for discharge tube type lamps which increases efficiency and has IEC-standard end of lamp life protection. Efficiency is enhanced by placing primary resonant capacitor (351a) in parallel with cathode conduction loop (270) while retaining a minimal secondary resonant capacitor (351b) within the cathode conduction loop (270). IEC-standard end of lamp life protection is achieved by placing the primary winding (323) of the base drive transformer (357) within the cathode conduction loop (270) of the ballast circuit, and employing a dampening capacitor (307) to suppress the erroneous base drive signals generated by coupling in the secondary windings (325, 327) as a lamp nears end of lamp life. Other embodiments are described and shown.

Abstract: A program start ballast powers multiple lamps coupled in parallel. A first inverter and a primary winding of a first transformer form a main circuit. A second inverter and a primary winding of a second transformer form a preheat circuit. One or more lamps are coupled in parallel across a secondary winding of the first transformer, and secondary windings of the second transformer are coupled across filaments at either end of the one or more lamps. The main circuit is configured to disable power across the first transformer during a preheat mode of operation and to provide power across the first transformer during a steady-state mode of operation. The preheat circuit is configured to provide power across the second transformer during the preheat mode of operation and to disable power across the second transformer during the steady-state mode of operation.

Abstract: A multi-lamp driving system includes a power supply and at least one balance transformer. Each balance transformer includes two cores, two primary windings, two secondary windings and two protection windings. Each primary winding is wrapped around a core and serially connected to a lamp to form a first circuit branch in parallel connection with each other. The first circuit branches are powered by the power supply. The Each secondary winding is wrapped around a core and connected to a primary winding. The two secondary windings are connected in series to form a short circuit loop. Each of the protection windings is wrapped around a core and connected to a primary winding. The protection windings are wrapped in opposite directions and connected in series to form a second circuit branch. The second circuit branch outputs voltage signals to the power supply when induced voltages crossing the protection windings are unequal.

Abstract: A transformer assembly (300) for use with an internal load (307) includes a transformer core (323) having a primary winding (405). A first electrode (303) and second electrode (319) are used for contacting an internal load (307). A secondary circuit is formed that includes the first electrode (303), the second electrode (319) and conductors (301,313, 317) positioned between the first electrode (303) and second electrode (319). The transformer assembly (300) is arranged so that the conductors (301, 313, 317) surround the primary winding (405), transformer core (323), the first electrode (301) and second electrode (319). The transformer assembly (300) may be used in an electrode furnace or other high current and voltage applications requiring high efficiency in a small package.

Abstract: An offline LED lighting circuit comprises a controller and a dimming circuit. The controller generates a switching signal to switch a transformer for generating an output voltage and an output current at an output terminal of the offline LED lighting circuit to drive LEDs. The dimming circuit is coupled to the controller to modulate the switching signal in response to a dimming signal. A first reference voltage and a second reference voltage of the controller are generated in response to the dimming signal. The switching signal is modulated by the first reference voltage and the second reference voltage. The controller regulates the output voltage at a first output level and a second output level in response to both the first reference voltage and the second reference voltage. The second output level is lower than the first output level.

Abstract: A driving device includes a dimmer, a rectifying-filtering unit, a rectifying-dividing unit, a control unit, and a voltage transforming unit. The dimmer is used for receiving an alternating current (AC) voltage from a power supply, and generating a primary voltage for controlling the brightness of a luminous element. The rectifying-filtering unit is used for rectifying and filtering the primary voltage to generate a secondary voltage. The rectifying-dividing unit is used for rectifying and dividing the primary voltage to generate a detecting voltage. The control unit is used for receiving the secondary voltage, and generating a pulse voltage whose duty cycle is variable with the detecting voltage. The voltage transforming unit is used for transforming the secondary voltage to a driving voltage for driving the luminous element to emit light according to the pulse voltage. A related electronic apparatus is also provided.

Abstract: A ballast circuit is disclosed for inductively providing power to a load. The ballast circuit includes an oscillator, a driver, a switching circuit, a resonant tank circuit and a current sensing circuit. The current sensing circuit provides a current feedback signal to the oscillator that is representative of the current in the resonant tank circuit. The current feedback signal drives the frequency of the ballast circuit causing the ballast circuit to seek resonance. The ballast circuit preferably includes a current limit circuit that is inductively coupled to the resonant tank circuit. The current limit circuit disables the ballast circuit when the current in the ballast circuit exceeds a predetermined threshold or falls outside a predetermined range.

Abstract: A circuit is used for driving a plurality of lamps, such as Cold Cathode Fluorescent Lamps (CCFLs). The lamps are paired to form a plurality of pairs of lamps. Each of the plurality of pairs of lamps has two lamps which are coupled to each other in series. The plurality of pairs of lamps are coupled in parallel. The circuit comprises a switch circuit, a transformer, and a plurality of balance chokes. The switch circuit is used for converting a DC electric power into a first AC electric power. The transformer has a primary winding and a secondary winding. The primary winding of the transformer is coupled to the switch circuit for receiving said first AC electric power and energizing the secondary winding to generate a second AC electric power from the secondary winding to energize the plurality of lamps. Each of the balance chokes includes a first winding and a second winding.

Abstract: An inverter circuit (20) includes a transformer (T2) including a primary winding and a secondary winding including a high voltage terminal, a first copper foil (P21), a power stage circuit (21) electrically connected to the primary winding, a detection circuit (22) including a second copper foil (P22) and an impedance (Z2), a protection circuit (23) outputting a protection signal, and a pulse width modulation controller (24) controlling output of the power stage circuit according to the protection signal. The second copper foil and the first copper foil are separated. An equivalent capacitor is formed between the second copper foil and the first copper foil, detecting voltage output from the high voltage terminal. The impedance is electrically connected between the second copper foil and ground, dividing a voltage detected by the equivalent capacitor.

Abstract: An inverter for driving at least one light-emitting unit includes a switching circuit, an electric-isolated circuit and a transforming circuit. The switching circuit generates at least one switching signal according to a DC signal and at least one switching control signal. The electric-isolated circuit has an electric-isolated side and a non-electric-isolated side, which is electrically connected to the switching circuit electrically and generates a first power signal according to the switching signal. The transforming circuit is electrically connected to the electric-isolated side of the electric-isolated circuit, and generates a second power signal to drive the light-emitting unit according to the first power signal.

Abstract: The present invention discloses a primary-side driving backlight circuit for LCD panel. The primary-side driving backlight circuit employs a single isolation device to achieve isolation request for safety for the secondary side. The PWM controller on the secondary-side of a transformer generates a control signal according to a feedback signal. The control signal is transmitted by the isolation device to a High/Low side driver. The High/Low side driver has a High Output and a Low Output, which drives power switches at high side and low side respectively, in order to control the power of an input source transmitting into the transformer and further control the voltage and current of cold cathode lamp(s) of a backlight circuit.

Abstract: The present invention is directed to a power control wiring device that includes an electronic switch circuit that energizes the electrical load in accordance with a timing regulation signal. A timing regulation circuit includes a primary timing regulation circuit and an auxiliary timing regulation circuit. The circuit is adjustable between a minimum power setting and a maximum power setting to thereby generate an adjustable primary timing regulation signal. The timing regulation circuit also generates an auxiliary timing regulation signal to thereby reduce power consumption. A primary manual power control mechanism is configured to adjust the primary timing regulation circuit between the minimum power setting and the maximum power setting. An auxiliary manual power control mechanism is configured to trim the maximum power setting in accordance with the selectable trim adjustment, the at least one auxiliary manual power control mechanism being user accessible.

Abstract: A drive circuit controls the on/off state of a switching transistor of a DC/DC converter. A first resistor is provided on a path of current flowing through a primary coil of a transformer connected to the switching transistor, and one end of the first resistor is grounded. A second resistor is provided on a path of current flowing through a secondary coil of the transformer, and one end of the second resistor is grounded. A switching controller turns off the switching transistor when a first detection voltage exceeds a first threshold voltage and, turns on the switching transistor after lapse of predetermined delay time since a second detection voltage exceeds the second threshold voltage.

Abstract: A backlighting arrangement constituted of: a driving transformer; at least one balancing transformer; a plurality of luminaires, a first end of each of the plurality of luminaires connected to a high voltage lead of the driving transformer and a second end of each of the plurality of luminaires connected to a unique end of a winding of the at least one balancing transformer, wherein each pair of the luminaires is associated with a particular winding of one of the at least one balancing transformers, and wherein the first end and the second end of each of the luminaires is in physical proximity of the driving transformer and the at least one balancing transformer, the constituent lamps of the luminaires arranged in parallel and generally extending axially away from the proximity of the driving transformer.

Abstract: A backlighting arrangement constituted of a driving transformer arrangement; a plurality of lamp pairs, each of the constituent lamps of the plurality of lamp pairs exhibiting a first electrical connection and a second electrical connection; and a plurality of balancing transformers, each comprising a primary winding and a secondary winding magnetically coupled to the primary winding, and each associated with a particular one of the plurality of lamp pairs, the primary winding of each of the plurality of balancing transformers serially connected between the second electrical connections of the constituent lamps of the associated lamp pair, the secondary windings of the plurality of balancing transformers serially connected in phase, with a first end of the serially connected secondary windings of the balancing transformers connected to one phase output of the driving transformer arrangement.

Abstract: A fluorescent lamp driving circuit is provided. The fluorescent lamp driving circuit collects a pulse-width-modulation and a MOS switch in a single package. The pulse-width-modulation for driving multiple lamps only needs two pins to achieve feedback control and protection control. Thereby the pins required by the pulse-width-modulation are decreased substantially, and the electronic elements needed for feedback and protection control are also reduced, and the overall circuit design is simplified.

Abstract: A dielectric barrier discharge lamp lighting device includes a transformer that supplies a driving voltage to a dielectric barrier discharge lamp from a secondary coil, and a driving circuit that controls an input voltage to the transformer to supply a driving voltage with a driving frequency fd to the dielectric barrier discharge lamp. The self-resonant frequency fr of the secondary coil, which is measured with the primary coil of the transformer being open, is equal to the driving frequency fd or a frequency in the vicinity of the driving frequency fd. This frequency fr satisfies, for example, 0.9 fd?fr?1.3 fd.

Abstract: A two-stage balancer for a multi-lamp backlight is electrically connected to a driving unit through a driving transformer. The two-stage balancer includes a plurality of first balancing transformers, second balancing transformers, and lighting units. Each of the first balancing transformers is electrically connected to the corresponding second balancing transformers to form a two-stage structure. In addition, a primary winding and a secondary winding of the second balancing transformer is electrically connected in series to one lighting unit, respectively, to form a circuit loop. Further, each of the circuit loops is electrically connected in parallel. Whereby the two-stage balancer provides much better current balance between the parallel circuit loops, and outputs a sinusoid-like driving current to increase lighting efficacy and further maintain uniform brightness of the multi-lamp backlight.

Abstract: A light source driving device for driving a light source module (22), includes a power stage circuit (20), a transformer and resonance circuit (21), a current balancing circuit (23), a feedback control circuit (25) and an fault detecting circuit (24). The power stage circuit converts received signals to alternating current (AC) signals. The transformer and resonance circuit converts the AC signals to electrical signals. The current balancing circuit balances current flowing through the light source module. The fault detecting circuit comprises a plurality of inputs (a1), (a2n (n=1, 2, 3, . . . , n)) and an output (b1). One of inputs is connected to one input of the current balancing circuit, other inputs are connected to outputs of the current balancing circuit, and the output outputs a fault signal. The feedback control circuit is used for controlling output of the power stage circuit.

Abstract: The present invention relates to a circuit arrangement for operating at least one electric lamp and at least one LED including: an inverter having a bridge circuit having at least one first bridge transistor and one second bridge transistor arranged in series with one another, a center point of the bridge circuit being defined between the first and second bridge transistors; a lamp supply unit for supplying the electric lamp with energy from the bridge circuit, which includes a supply line with an inductance, via which the center point (M) of the bridge circuit is coupled to a first connection for the electric lamp; the lamp supply unit including an LED supply unit, which is designed to supply the at least one LED with energy. Moreover, it relates to an operating method for at least one electric lamp and at least one LED using such a circuit arrangement.

Abstract: A discharge lamp lighting circuit is provided. The discharge lamp lighting circuit includes an inverter circuit which has two output ends; a series resonant circuit which includes a capacitor, an inductor and a transformer, coupled in series; a driving portion; and a controlling portion which provides a control signal for controlling said inverter circuit, said controlling portion including a first signal producing portion which produces a first signal indicative of a phase of a current flowing through said series resonant circuit; and a second signal producing portion which produces a second signal indicative of a phase of the AC voltage output from said inverter circuit, said controlling portion producing the control signal on the basis of a phase difference between the first and second signals, wherein one component of said series resonant circuit is coupled between one of said output ends, and a detection point.

Abstract: Provided is a power supply device including a power supply unit that supplies a driving voltage for driving at least one or more loads; a current balancing unit that maintains a current balance of the driving voltage supplied to the respective loads; a detection unit that detects currents flowing in the current balancing unit through electromagnetic induction so as to output a detection signal; and a control unit that receives the detection signal to judge whether the loads are opened or not and outputs a control signal for controlling the magnitude of the driving voltage.

Abstract: A lamp base (2) for a high-pressure discharge lamp comprises an ignition transformer (1000), which is placed in the interior (214) of the lamp base (2) and which serves to ignite the gas discharge inside the high-pressure discharge lamp. To this end, the ignition transformer (1000) comprises a core on which its windings (1001, 1002) are placed. The core is formed by a first core part (1004) and by at least one second core part (1005, 1006, 1007), which are each made of a ferromagnetic or ferrimagnetic material and are separated by at least one gap (10078). The first core part (1004) has a cylindrical section on which the windings (1001, 1002) of the ignition transformer (1000) are placed, and core parts (1004, 1005, 1006, 1007) are formed in such a manner that the core, apart from the at least one gap (1008), has a closed shape.

Abstract: The present invention provides a system for controlling one or more operating unites in an inductive power transfer (IPT) system. Each operating unit includes a pick-up coil that takes power from a primary conductor or track over an air gap. The operating unit is controlled by frequency modulating the primary conductor power supply to send a control instruction which is decoded by the operating unit. The instruction is decoded by generating a signal using a local oscillator in the operating unit and using the signal to detect changes in the frequency of the current in the primary conductor. Such a system can be used, for example, to control inductively powered road-studs that include a light source for controlling traffic on a roadway. A narrow band modulated data transmission system and method for controlling an operating unit are also provided.

Abstract: A method for dimming multiple lamps includes: getting a brightness range of a lighting area which has at least two light sources, getting a dimming range of the light sources, setting the brightness of the lighting area, determining the dimming value of each light source, and defining different dimming values of at least two light sources. The luminosity adjustment upper limit and lower limit of the individual light sources are obtained. After the brightness of the lighting area is set the dimming value of each light source is determined to form the brightness of the lighting area through the two light sources of different brightness.

Abstract: A power supply system of a light source includes a luminance control unit, luminance adjusting unit, control circuit and voltage transformer. The luminance control unit is for receiving a turn-on signal and outputting a first luminance signal during a predetermined time period. The luminance adjusting unit is for outputting a second luminance signal according to an input of a user. The control circuit is for outputting a power control signal according to the first luminance signal and the second luminance signal. The voltage transformer is for outputting an AC voltage for driving a light source according to the power control signal. During the predetermined time period, the control circuit outputs the power control signal according to the first luminance signal and after the predetermined time period, the control circuit outputs the power control signal according to the second luminance signal.

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: While series resonant circuits 51 to 53 are connected to an output stage of a switching circuit 101 so as to be parallel mutually, primary sides of booster transformer sections 1 to 3 are connected to resonance capacitors 14 to 16 respectively, and further, CCFLs 21 to 23 are connected to secondary sides of the booster transformer sections 1 to 3 respectively.

Abstract: An improved driving circuit for piezoelectric lamps includes a power switch unit and at least one piezoelectric transformer. The power switch unit is connected to a power source. ON/OFF of the power switch unit controls power amount transmitted to the piezoelectric transformer. The piezoelectric transformer transforms the power and drives at least one load. Operation of the power switch unit is controlled by a duty cycle signal generated by a pulse modulation unit. The pulse modulation unit is connected to a buffer unit which generates a time series at start time to suppress instant output of the piezoelectric transformer, thereby to improve the problem of voltage surge at the start time happened to the conventional piezoelectric transformers.

Abstract: A circuit arrangement for operating a high pressure discharge lamp includes a voltage transformer, a load circuit which is supplied by the voltage transformer and provided with connections for the high pressure discharge lamp (La), a choke (L2b) for limiting a current passing through the high pressure discharge lamp (La) and with an impulse igniting device for igniting a gas discharge therein, wherein the choke (L2b) is embodied in the form of the secondary winding of the igniting transformer (T2) of the impulse igniting device.

Abstract: A transformer for driving multiple lamps includes a core, a primary winding set, a secondary winding set and a balancing winding set. The primary winding set winds around the core and includes a first primary coil. The secondary winding set winds around the core and includes a first secondary coil. The balancing winding set winds around the core and includes a first balancing coil and a second balancing coil which wind around the core in a combinative way. The primary winding set, the secondary winding set and the balancing winding set have the same magnetic-flux loop in the core.

Abstract: A ring balancer comprising a plurality of balancing transformers facilitates current sharing in a multi-lamp backlight system. The balancing transformers have respective primary windings separately coupled in series with designated lamps and have respective secondary windings coupled together in a closed loop. The secondary windings conduct a common current and the respective primary windings conduct proportional currents to balance currents among the lamps. The ring balancer facilitates automatic lamp striking and the lamps can be advantageously driven by a common voltage source.

Abstract: A ring balancer comprising a plurality of balancing transformers facilitates current sharing in a multi-lamp backlight system. The balancing transformers have respective primary windings separately coupled in series with designated lamps and have respective secondary windings coupled together in a closed loop. The secondary windings conduct a common current and the respective primary windings conduct proportional currents to balance currents among the lamps. The ring balancer facilitates automatic lamp striking and the lamps can be advantageously driven by a common voltage source.

Abstract: Apparatus for sequentially igniting and serially operating a pair of high output rapid start fluorescent lamps from a source of AC voltage. The apparatus includes a transformer with a primary winding that may be subdivided in two sections, a principal secondary winding connected in series aiding with one section of the primary and in opposition with the other primary section. This arrangement provides the advantage of developing a comparatively high open circuit voltage for starting the lamps without exceeding lamp holder voltage ratings.