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: An apparatus and method for driving a lamp are provided. In one embodiment, an inverter having four switching elements is split into two inverter arms that are deployed at separate terminals of a floating lamp structure to achieve even light output. A controller drives both inverter arms such that power switching lines do not cross the floating lamp structure. In one embodiment, the controller adjusts the brightness of the lamp structure by adjusting the phase difference between outputs of a first inverter arm relative to a second inverter arm. In one embodiment, the controller adjusts the brightness by symmetrically pulse width modulating the outputs of the first inverter arm and the second inverter arm.

Abstract: Methods and apparatus are disclosed for balancing currents passing through multiple circuit loads and in some cases through fluorescent lamps. Multiple-leg magnetic cores are wound in specific manners to simplify current balancing. Conventional three- or more than three-legged EE- and EI-type magnetic cores, with disclosed windings are used to balance current in circuits with multiple branches, such as connected Cold Cathode Fluorescent Lamps (CCFLs).

Abstract: There is provided a discharge lamp lighting apparatus including common lines to which the low voltage side outputs of step-up transformers having a plurality of discharge lamps connected thereto are connected, wherein the low voltage side outputs connected to the common lines include two kinds of outputs in an equal number at which respective lam currents are phase-shifted by 180 degrees from each other. The discharge lamp lighting apparatus further includes: malfunction detecting circuits which is composed of sense resistors to sense the lamp currents synthesized on the common lines and comparators to compare with a sense voltage with a predetermined reference voltage, and which outputs a malfunction detecting signal when the sense voltage exceeds the reference voltage; and a protection circuit to stop driving of bridge circuits according to the malfunction detecting signal.

Abstract: According to an embodiment, a power supply system has a primary side and a secondary side. An input terminal on the primary side is operable to receive an input voltage. An output terminal on the secondary side is operable to be connected to a load for providing current thereto. Circuitry is provided which is operable to regulate the power supply system from the primary side so that the current provided to the load at the output terminal is substantially constant.

Abstract: Disclosed is a liquid crystal display panel which includes a switching circuit for converting an input voltage into an alternating current (AC) voltage, a transformer for boosting the AC voltage generated from the switching circuit, and a bypass capacitor part connected in parallel between an output terminal of the switching circuit and the transformer.

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: A high frequency sinusoidal wave is generated and applied directly to a gas discharge lamp in a power efficient electronic ballast. Uniting a high frequency current fed oscillator with a transformer, where direct current may be applied to the center tap of the transformer primary winding to enable the impression of a sinusoidal alternating current at the secondary winding. This sinusoidal alternating current is applied directly to a gas discharge lamp. Feedback from the transformer controls the switching of the oscillator at resonant frequency.

Abstract: A lamp driving device has a pulse width modulation circuit, a phase splitter and several switching circuits. The pulse width modulation circuit is arranged to generate a pulse width modulation signal. The phase splitter is coupled to the pulse width modulation circuit and arranged to split the pulse width modulation signal into several phased signals having different phases, wherein pulses of each phased signal are non-overlapping with those of another phased signal. The switching circuits are coupled to the phase splitter and are arranged to respectively receive one of the phased signals, wherein each switching circuit is controlled by the received phased signal.

Abstract: An AC/CD lamp holder includes a first lamp base having a first end adapted to electrically connect to an AC power source; and an AC/DC transformer having an AC side electrically connected to a second end of the first lamp base opposite to the first end thereof, and a DC side provided with at least one coupling section for electrically connecting with positive and negative electrodes of a DC lighting device. The AC/DC transformer and the first lamp base are formed into one integral body. A DC lighting device can be directly connected to the coupling section of the AC/DC lamp holder to obtain power from a conventional AC power source and provide the illuminating effect. A user needs not to change the whole power supply system or externally connect an AC/DC transformer to the AC power source to thereby save the cost for changing the power supply system.

Abstract: A power supply for supplying power to a lamp with functions of dimming, over-current protection, over-voltage protection, arcing protection, and low-temperature start-up is provided. When frequency of the output current exceeds a predetermined value, the power supply is turned off to accomplish a dimming goal and extend lifetime of the lamp. When abnormal statuses such as open-circuited status, short-circuited status, or arcing status occur, a surge current induced by the abnormal statuses may be eliminated to prevent the power supply from being damaged. A high-frequency current detection circuit is configured to detect whether a current supplied to the high-voltage load is a high-frequency current to prevent damage to the electronic elements in the high-voltage load. A current adjusting circuit is configured to adjust an alternating current outputted to a lamp set in response to an environment temperature to supply an adequate alternating current at a low temperature for starting the lamp set.

Abstract: The invention is a driving apparatus and circuit for efficiently converting a direct current (DC) signal into an alternating current (AC) signal to drive a fluorescent lamp. A semi class E configuration which utilizes only one transistor is employed in the invention. The invention comprises a power transistor, a transformer wherein a primary winding is used as a load for the power transistor and a secondary winding is used to transfer energy to the load for the driving apparatus, i.e. the CCFL tube, and control means which extracts the frequency and current of the power transistor and corrects the deviation between the frequency of the power transistor and that of the control means.

Abstract: A multiple discharge lamp lighting device in which lamp current of discharge lamps is equalized by using a circuit structure having transformers on both sides of the discharge lamps and in which the number of parts can be reduced. A multiple discharge lamp lighting device 10 according to the present invention includes the same number of first transformers TA1 to TAn as the number of discharge lamps La1 to Lan and one second transformer TB. One end of a secondary winding (e.g., Ns1) on the non-grounded side of the first transformer (e.g., TA1) is connected to one end of one corresponding discharge lamp (e.g., La1). One end of a secondary winding Ws on the non-grounded side of the second transformer TB is connected to a second end of each of the discharge lamps La1 to Lan.

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: A device for igniting the gas discharge in a high-pressure discharge lamp (La). The igniting device is embodied as a pulsed igniting device (C, FS, Tr1) while a piezoelectric transformer (PT) is provided for supplying the pulsed igniting device (C, FS, Tr1) with voltage.

Abstract: A self-excited inverter comprises a pair of switching devices and a transformer having a primary side to which the switching devices are connected and a secondary side to which a lamp is connected. A pulse voltage is applied alternately to gates of the individual switching devices through a drive winding of the transformer, causing the switching devices to turn on and off in alternate turns to produce an AC voltage which is supplied from a pair of main windings of the transformer to the secondary side thereof. An input voltage supplied to the main windings of the transformer is divided by a voltage divider circuit configured with a plurality of resistors and voltages divided by the voltage divider circuit are applied to the gates of the individual switching devices so that the startup voltage follows the input voltage.

Abstract: A plasma supply device generates an output power greater than 500 W at an essentially constant basic frequency greater than 3 MHz and powers a plasma process to which is supplied the generated output power, and from which reflected power is returned to the plasma supply device. The plasma supply device includes at least one inverter connected to a DC power supply, which inverter has at least one switching element, and an output network. The output network is arranged on a printed circuit board. The output network can therefore be designed low priced and accurately.

Abstract: There is provided a backlight driving system for a liquid crystal display that can reduce size and weight of a product because a DC-DC converter is not used when commercial AC power is converted into lamp driving power. A backlight driving system for a liquid crystal display according to an aspect of the invention includes a power supply unit converting commercial alternating current (AC) power into direct current (DC) power having a voltage level set beforehand, an inverter unit converting the DC power from the power supply unit into AC power at a one-to-one conversion ratio set beforehand, a boosting unit boosting the AC power from the inverter unit into lamp lighting power set beforehand; and a lamp group receiving the lamp lighting power from the boosting unit to emit light.

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 system for driving a multi-lamp, and more particularly to, a system for driving a multi-lamp for driving a parallel arrangement of a plurality of discharge lamps and a method of driving a plurality of discharge lamps and a method thereof.

Abstract: The present invention provides a power supply suitable for a neon light, which power supply has a continuous output and a high power factor in excess of 0.9. The present invention does not require a front-end boost converter.

Abstract: A lamp driver circuit supplies an alternating current having an operating frequency to a lamp, e.g. a fluorescent lamp, for operating the lamp. To switch off the lamp, the frequency of the alternating current is changed to a non-operating frequency. Due to the frequency change, the impedance of an impedance element of the lamp driver circuit is changed. As a result, the lamp current decreases to zero and the lamp extinguishes. According to the invention, the current having the non-operating frequency is employed to generate a voltage to be supplied to a further circuit, such as a control circuit. Thus, the lamp driver circuit and an associated control circuit may operate in an operating mode or in a standby, i.e. non-operating, mode without requiring a separate voltage supply source. In the standby mode, the control circuit may be controlled to switch the lamp driver circuit from the non-operating mode into the operating mode, thereby switching the lamp on.

Abstract: A circuit for the generation of ignition pulses for a lamp has: an ignition pulse transformer, a device for the generation of ignition pulses (ignition pulse generator) at a primary winding of the ignition pulse transformer, which are transformed in the secondary winding of the ignition pulse transformer, a voltage detector for the detection of the voltage value of the transformed ignition pulses, and a voltage regulator for regulating the voltage value of the transformed ignition pulses to a predetermined reference value. The ignition pulse generator has, in a series circuit, a pulse capacitor and a switch, parallel to the secondary winding of the ignition pulse transformer and the lamp, wherein the regulator for the voltage value of the transformed ignition pulses sets at the pulse capacitor the voltage applied at an ignition time point. The voltage at the pulse capacitor can be set by means of selection of the switch-on and/or switch-off time points of the switch.

Abstract: A transformer driver capable of making a load current constant with a simple configuration is provided. A driver 10 of the present invention applies a drive voltage Vd to the primary side of a piezoelectric transformer 11 in which a load 12 is connected to the secondary side. The angular frequency ?0 of the drive voltage Vd is a series resonance angular frequency given by an equivalent circuit on the output side of the driver 10. With the driver 10, a load current IL can be constant irrespective of the impedance ZL of the load 12 with a simple configuration. Therefore, the load current IL can always be constant even if the impedance ZL of the load 12 varies.

Abstract: A light weight, bobbinless high voltage transformer and igniter module is provided that meets low-cost and high-reliability requirements for automotive HID products. A printed circuit board (112) serves as a carrier for low voltage electronic components. A high voltage bar core transformer (114) is held in a cradle (130, 130?) that accommodates potting material and has a channel (160) that receives a high voltage wire extending from the transformer for connection with a lead (104) of an HID lamp (100). Thin walls (210, 212) allow the cradle to serve as the cavity for the potting of the transformer. In addition, multi-layer dielectric material is disposed between the primary and secondary windings. Preferably, the primary winding (196) is a strap that covers a large surface area of the secondary winding (192).

Abstract: A discharge tube drive circuit for driving a plurality of discharge tubes is proposed with reduced number of parts and in a down-sized form. A first balance transformer is provided in a first drive circuit block, and a plurality of primary coils of a plurality of drive transformers in the first drive circuit block and a secondary coil of the first balance transformer are connected in series. A second balance transformer is provided in a second drive circuit block, and a plurality of primary coils of a plurality of drive transformers in the second drive circuit block and a secondary coil of the second balance transformer are connected in series. Further, a primary coil of the balance transformer and a primary coil of the second balance transformer are connected in series to configure the discharge tube drive circuit of the present invention.

Abstract: A current driven toroid-free feedback type ballast comprising a filter and rectifier circuit, a switch and resonant circuit and a lamp load including capacitors, wherein the filter and rectifier circuit is coupled to input ends of the switch and resonant circuit with its output ends; the switch and resonant circuit is coupled to the lamp load with its output ends and comprising: a trigger circuit comprised of resistors R1, R2, a capacitor C3, a diode D5 and a trigger diode DB3; a half bridge circuit comprised of transistors Q1, Q2 and resistors; and a three winding transformer T comprised of primary winding T3 and two secondary windings T1, T2.

Abstract: A power system for driving a plurality of lamps includes a transformer circuit, a current balancing circuit, and a light source. The transformer circuit includes a plurality of transformers in a quantity denoted by N, and each of the transformers has a first, a second, a third, and a fourth output ends. The current balancing circuit includes a plurality of current balancing units each having two output ends. The 2Nth current balancing unit is connected to a fourth output end of the Nth transformer, and the (2N?1)th current balancing unit is connected to a first output end of the Nth transformer. The light source has a plurality of lamps each having one end connected to a respective output end of the current balancing units and another end grounded. The numbers of the current balancing units and the lamps are respectively twice and four times the quantity N of the transformers.

Abstract: The present invention uses one or more transformers disposed between an inverter driver to drive a plurality of lamps. Each transformer has a first coil and a second coil magnetically coupled to each other. Each of the first and second coils has an input end and an output end. The input end of the first coil is operatively connected to the input end of the second coil for receiving an input current. Each of the first and second coils has a capacitor connected between the input and output ends. The output ends of the first and second coils are used to provide output current in two separate current paths. As such, the output end of a transformer can be separately connected to the input end of two lamps or two such transformers.

Abstract: An inductive power supply system for providing power to one or more inductively powered devices. The system includes a mechanism for varying the physical distance or the respective orientation between the primary coil and secondary coil to control the amount of power supplied to the inductively powered device. In another aspect, the present invention is directed to an inductive power supply system having a primary coil and a receptacle disposed within the magnetic field generated by the primary coil. One or more inductively powered devices are placed randomly within the receptacle to receive power inductively from the primary coil. The power supply circuit includes circuitry for adjusting the power supplied to the primary coil to optimize operation based on the position and cumulative characteristics of the inductively powered device(s) disposed within the receptacle.

Abstract: A DC/AC cold cathode fluorescent lamp (CCFL) inverter circuit includes a transformer with a primary winding and a secondary winding for providing increased voltage to a CCFL, a first and second MOSFET switches for selectively allowing direct current of a first polarity and a second polarity to flow through the transformer respectively. The primary and secondary windings of the transformer are electrically coupled to ground. A capacitor divider is electrically coupled to the CCFL for providing a first voltage signal representing a voltage across the CCFL. A first feedback signal line receives the first voltage signal. A timer circuit is coupled to the first feedback signal line for providing a time-out sequence of a predetermined duration when the first voltage signal exceeds a predetermined threshold. A protection circuit shuts down the first switch and the second switch when the first voltage signal exceeds the predetermined threshold after the predetermined duration.

Abstract: A backlight unit includes a plurality of fluorescent lamps driven by one inverter in a manner to prevent wave noise. A first common electrode line connects respective first ends of the odd numbered fluorescent lamps in common. A second common electrode line connects respective first ends of the even numbered fluorescent lamps in common. A third common electrode line connects the second ends of the odd and even numbered fluorescent lamps in common. Voltages having opposite phases are respectively applied to the first common electrode line and the second common electrode line.

Abstract: A display apparatus includes a display panel and a backlight assembly including a lamp and an inverter. The inverter includes a main transformer, a main driver and a voltage controller. The main transformer applies a driving alternating current (AC) voltage to the lamp. The main driver generates an output signal controlling the main transformer based on a feedback signal from the main transformer. The voltage controller is electrically connected to a feedback terminal of the main driver to control a maximum level of a voltage applied to the feedback terminal.

Abstract: An exemplary balance controlling circuit (100) includes a transformer (T11), a first capacitor (C11), a second capacitor (C22), a first inductor (TC11), and a second inductor (TC12). The transformer includes two inputs (41, 42) connected to an external circuit, a grounded first output (43) and a second output (44). The second capacitor (C12) includes a first port (121) configured to connect to ground, and a second port (122) connected to the second output of the transformer. The first capacitor (C11) includes a second port (112) connected to the second output of the transformer, and a first port (111) connected to the first inductor and the second inductor. The first inductor includes a first output port (I1). The second inductor includes a second output port (I2), and a third output port (I3).

Abstract: A discharge lamp lighting apparatus includes switching elements to pass a current to a primary winding of a transformer and a capacitor, an oscillator to generate a triangular signal, an error amplifier to amplify an error voltage of a voltage corresponding to a current passed through a discharge lamp and receive a burst dimming signal that is a pulse signal to intermittently supply power to the discharge lamp, comparators to compare the error voltage with the triangular signal and generate PWM control signals that turn on/off the switching elements, respectively, a clamp circuit to clamp an output from the error amplifier so that the output from the error amplifier may not drop below a lower limit value of the triangular signal during an OFF period of the burst dimming signal, and breaking circuits to block the PWM control signals during the OFF period of the burst dimming signal.

Abstract: A driving device for driving a light source module (32) includes a switch circuit (30), a transformer circuit (31), a voltage sensing circuit (34), a current sensing circuit (35), and a PWM controller (33). The switch circuit converts a received direct current (DC) power signal to an alternating current (AC) signal. The transformer circuit converts the AC signal to an appropriate signal to drive the light source module. The voltage sensing circuit receives the DC power signal and senses a voltage level of the DC power signal. The current sensing circuit receives the DC power signal and senses a current level of the DC power signal. The PWM controller controls the AC signal output from the switch circuit according to the sensed voltage and current levels.

Abstract: A method and a circuit arrangement (1) for operating a high intensity discharge lamp (2), which is supplied by direct current (DC) supply lines (4, 6), comprising a transformer (40), of which a primary winding (42) is connected in series with an inductor (46) and a capacitor (48) to the DC supply lines (4, 6), a secondary winding (44) of the transformer is connected in series with the lamp, a switch (52) is connected in parallel to the capacitor (48), and a control circuit (56) is connected to the switch (52), whereby the control circuit (56) controls the switch to conduct upon detecting a zero crossing of a voltage (Vsw) at the switch, and the control circuit controls the switch to not conduct upon detecting a value of a current through the switch which is greater than a reference value.

Abstract: There is provided a high-voltage pulse generator with a reduced radius of rotation and improved performance, and a lighting apparatus and a vehicle having the high-voltage pulse generator. The high-voltage pulse generator includes a pulse transformer in which a primary winding and a secondary winding are wound on a core, a discharge lamp connector which is formed in a tube shape having an opened front surface and a bottom out of an insulating material and which has an inner-electrode terminal electrically connected to a high voltage part of the secondary winding in the bottom, and a pulse generating capacitor and a discharge switch electrically connected to the primary winding of the pulse transformer. The discharge lamp connector is disposed so that the center thereof is located in a center line passing through a substantial center in an axis direction (a direction parallel to a center line) of the pulse transformer and perpendicular to the axis direction.

Abstract: A power supply for discharge lamp includes a transformer and a current balance device, wherein the transformer includes a primary winding and a secondary winding and the current balance device is coupled between the secondary winding and a plurality of discharge lamps. The current balance device may include a single inductor wherein at least two windings are connected in series with each other and each serially-connected winding is coupled with a discharge lamp, and the other windings are respectively coupled with a discharge lamp. The current balance device may include two inductors wherein at least one winding of a first inductor is connected in series with at least one winding of a second inductor and each serially-connected winding is coupled with a discharge lamp, and the other windings of the first inductor and the other windings of the second inductor are respectively coupled with a discharge lamp.

Abstract: A feedback and protection circuit is provided for detecting voltage and current of a cold cathode fluorescent lamp (CCFL) of a liquid crystal display (LCD) panel backlight apparatus and integrating all voltage and current input signals to output single current and voltage feedback signals to a PWM controller, so as to stabilize and control the voltage and current of the CCFL and determine whether any detected input signal is abnormal. If any CCFL is short circuited (CCFL is touched by people) or open circuited (CCFL is not lit), an abnormal status protection signal will be produced and sent to the PWM controller to stop all outputs of the backlight apparatus to prevent damages to circuit components or injuries to people. The circuit is designed in an integrated circuit to achieve the effects of reducing the area occupied by the circuit component layout and lowering the overall cost.

Abstract: To realize an LED drive circuit capable of feeding equal currents to parallel-connected LED circuits with a simple arrangement, there are provided a current source generating a temporally altering current and a first smoothing capacitor and a second smoothing capacitor, and there are also provided: a first LED circuit, containing one LED or series-connected LEDs, which is connected in parallel with the first smoothing capacitor; and a second LED circuit, containing one LED or series-connected LEDs, which is connected in parallel with the second smoothing capacitor, the drive circuit comprising: a current-dividing coil containing two coils coupled at a tap so that the current generated in the current source flows into the tap; a first reverse current blocking diode connected between an end of the current-dividing coil and an electrode of the first smoothing capacitor; and a second reverse current blocking diode connected between another end of the current-dividing coil and an electrode of the second smoothing

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: An output transformer or inductor for electronic ballast which having a number of electronic components including diodes, transistors, resistors, various type of capacitors and different transformers/inductors mounted on a top surface of a PCB (printed circuit board) within a compact housing which envelops the whole ballast assembly. The PCB (printed circuit board) configured to relocate the output-transformer or inductor to an edge of the PCB (printed circuit board) away from the rest of the electronic components. The output-transformer terminal (the transformer's bobbin) has at least two of L-shaped brackets locked to the PCB's (printed circuit board) edge at its top surface. The output-transformer is designed in a cantilevered mounting so that it is able to quickly dissipate its operational heat to the ballast compact case with less interfered by other components. It also saves the PCB (printed circuit board) material cost because it uses shorter PCB.

Abstract: Output of a chopper circuit is converted to a rectangular wave by a push-pull circuit, and is provided to a step-up transformer. When a switch is turned on, the control voltage of the chopper circuit is relatively low, and a high output voltage is provided to the transformer. Thus, the discharge lamp starts with certainty. When the discharge lamp starts, the transistor is turned on, and the resistance generating the control voltage is connected in parallel to other resistance, and the control voltage is increased. Thus, the output of the chopper circuit is decreased, and thereafter becomes a constant voltage. Thus, the dielectric barrier discharge lamp is started with certainty, and also is driven with stability.

Abstract: Disclosed are a lamp igniter module and method of assembling a lamp igniter module. The lamp igniter module comprises a transformer carrier, a slide-in electrical connector, a pc board, and a housing. Assembly of the lamp igniter module is accomplished by initially inserting a transformer carrier assembly within the housing and subsequently installing a slide-in electrical connector which may or may not be attached to the pc board.

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: Disclosed is a low-cost parallel lighting system for discharge lamps for a surface light source, which reduces nonuniform brightness and static noise, and fulfills a requirement that lamp currents of individual cold-cathode fluorescent lamps should be uniform and stabilized.

Abstract: A voltage sensing circuit (230) for sensing voltage signals of input alternating current (AC) signals includes a plurality of voltage dividing circuits (23n (n=1, 2, 3, . . . , n)) and a charging circuit (232). The voltage dividing circuits are used for dividing voltage signals of the input AC signals. The voltage dividing circuits are connected to the charging circuit, and then the divided voltage signals can be transmitted between the voltage dividing circuits, thereby pulling high corresponding DC levels of the divided voltage signals.

Abstract: There is provided a backlight unit that determines whether a lamp performs an abnormal operation by detecting a voltage that is induced in a power conversion transformer without using a complicated and expensive detection circuit. A backlight unit having a protection circuit using induced voltage detection according to an aspect of the invention includes an inverter part including a primary coil receiving power and at least one secondary coil converting the power from the primary coil to AC power set beforehand, a lamp part including at least one lamp receiving the AC power from the inverter part to emit light, a detection part including conductors detecting voltages electromagnetically induced in the secondary coil, and an abnormality determining part comparing detection voltages from the detection part with a reference voltage set beforehand.

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.