Abstract: Provided is a transformer (1), which includes: a core (10) which forms a magnetic circuit and has a middle leg (10a) and a plurality of side legs (10b, 10c) branched from the middle leg (10a); primary windings (11) respectively wound around a first winding leg (10a) and a second winding leg (10b), which are selected from the middle leg (10a) and the side legs (10b, 10c); and a secondary winding (12) wound around either of the first winding leg (10a) or the second winding leg (10b), wherein a first magnetic flux generated by the primary windings (11) from the first winding leg (10a) and a second magnetic flux generated by the primary windings (11) from the second winding leg (10b) differ from each other by a predetermined value or more at a position at which the fluxes do not intersect with the secondary winding (12).

Abstract: A light emitting diode (LED) driver includes an inverter for converting a DC input signal to a pulsating signal. A multiple output multi-resonant converter generates a first LED string current in response to the pulsating signal, and also generates a second LED string current in response to the pulsating signal. A transistor that may be a FET or BJT operating in its linear region regulates the second LED string current independent of the first LED string current without sacrificing efficiency of the overall power train.

Abstract: The present invention relates to electrical transformers and, in particular, to improvements to efficiency in energy conversion in electrical transformers. The improved transformer has a bi-toroidal circuit topology in which the magnetic flux passing through the primary and secondary coils are different. The turns ratio displays an “effective magnification” like an impedance transformed by a feedback loop. The result is a transformer which displays virtually no primary input current increase from no-load to on-load and an on-load power factor of zero for a purely resistive load.

Abstract: An LED lighting system is provided. The LED lighting system includes a main transformer, a voltage detector, a current controller, a second reference voltage supplier, and a power factor compensation circuit. The main transformer transforms an input signal to supply the transformed input signal to an LED group. The voltage detector supplies a control voltage proportional to a level of an input voltage corresponding to the input signal. The current controller includes a first voltage storage, a negative voltage applier, a second voltage storage, switch, and a current control signal generator. The first voltage storage stores the control voltage supplied from the voltage detector or discharges a stored voltage. The negative voltage applier is connected to the first voltage storage, and connected to a ground to apply the control voltage to the ground when the control voltage is a negative voltage.

Abstract: In various embodiments, a control system for an electronic circuit iteratively applies voltage to and senses current from a load to regulate operation of the load.

Abstract: An induction RF fluorescent lamp includes a lamp envelope with a re-entrant cavity both covered on a partial vacuum side with phosphor and filled with a working gas mixture; a power coupler on the non-vacuum side of said re-entrant cavity comprising a ferromagnetic core overwound with at least one turn of an electrical conductor; an electronic ballast, wherein the ballast converts mains frequency voltage and current to a power coupler frequency voltage and current, the electronic ballast providing the voltage and current to the power coupler through at least two of a plurality of electrical terminals of the electronic ballast; a capacitor electrically connected between the ferromagnetic core and at least one of the plurality of electrical terminals of the electronic ballast, wherein the magnitude of the impedance of the capacitor is high at the mains frequency and the magnitude of the impedance of that same capacitor is low at the operating frequency of the RF fluorescent lamp.

Abstract: An electronic ballast for driving a light-emitting device, includes a square wave generator having a plurality of switch elements for converting a DC input voltage into a square-wave AC voltage. A transformer has a driving winding and a plurality of inductive windings mutually connected with each other, in which at least a portion of the inductive windings are respectively connected to a control terminal of the switch element. A resonant circuit connects the driving winding and a light-emitting device and converts the square-wave voltage into an AC output voltage to drive the light-emitting device. An auxiliary control unit connected to the transformer regulates a voltage waveform of the driving winding or a voltage waveform of the inductive winding according to a control signal, thereby changing the voltage waveform of the inductive winding connected to the switch element to adjust the switching frequencies of the switch elements.

Abstract: Systems and methods are provided for providing a substantially constant and equal current to a plurality of current driven loads. In one embodiment, a system is provided that comprises a plurality of current regulated outputs and a plurality of current driven loads. The plurality of current regulated outputs and the plurality of current driven loads are arranged in a single current loop configuration with a respective current regulated output providing an output voltage to a respective current driven load of the plurality of current driven loads.

Abstract: A driving circuitry arranged to pass a dead time over an isolation transformer, the driving circuitry constituted of: a three-state driver arranged to output a first signal, the first signal selectively at one of two complementary voltage levels and a high impedance state; a first capacitor, a first end of the first capacitor coupled to receive the first signal; and a first isolation transformer, a first end of a first winding of the first isolation transformer coupled to a second end of the first capacitor.

Abstract: A lighting device such as an electronic ballast or LED driver includes circuitry to detect power converter activity and act accordingly. A power factor correction (PFC) circuit includes an inductor, a power converter switch, and a PFC controller effective to provide driving signals the power converter switch to turn on and off. A power converter activity detection circuit includes a first capacitor coupled between the PFC controller and the power converter switch, a zener diode, and a second capacitor coupled between the first capacitor and ground. An output voltage for the power converter activity detection circuit as referenced from a node between the first capacitor and the second capacitor is representative of activity by the power converter switch, and is provided to a lighting device controller which may accordingly maintain operation of the lighting device where a mains power interruption is only temporary but would otherwise disable the device.

Abstract: An apparatus and computer readable storage medium are disclosed for supplying power to a load such as a plurality of light emitting diodes. A representative apparatus comprises a primary module, a first secondary module couplable to a first load, and a second secondary module couplable to a second load. The primary module comprises a transformer having a transformer primary. The first secondary module comprises a first transformer secondary magnetically coupled to the transformer primary, and the second secondary module comprises a second transformer secondary magnetically coupled to the transformer primary, with the second secondary module couplable through the first or second load to the first secondary module.

Abstract: A LED drive circuit according to the present invention comprises a controller and a programmable signal. The controller generates a switching signal coupled to switch a magnetic device for generating an output current to drive a plurality of LEDs. The programmable signal is coupled to regulate a current-control signal of the controller. The switching signal is modulated in response to the current-control signal for regulating the output current, and the level of the output current is correlated to the current-control signal.

Abstract: Methods and apparatus are described that can provide improved power factor correction and total harmonic distortion, efficiency and/or direct feedback of load current variations to a power source inverter. In one example, a power supply, for example, a ballast, can have an input circuit, an output circuit and an inverter circuit coupled between the input circuit and the output circuit. A current feedback circuit is coupled between the output circuit and the inverter circuit and configured to feed current back to the inverter circuit through a transformer stage separate from the inverter as a function of a current level in the output circuit.

Abstract: Data may be encoded onto a direct current power line by modulating the current on that direct current power line. One method of modulating the current is by placing an inductor on the power line and then using a controlled transistor that turns on and turns off. The inductor will ensure that current keeps flowing but the transistor will induce changes in the current pattern. The excess current from when transistor is turned off must be diverted. Furthermore, to create symmetrical current changes, the inductor should be reverse biased. Thus, a circuit is created that sinks the excess current from when the transistor is turned off and used to reverse bias the inductor.

Abstract: A power supply apparatus for LED is provided. The power supply apparatus for LED includes a transformer, a first output unit, and a second output unit. The transformer includes a primary winding, a secondary winding receiving a power induced from the primary winding, and a tertiary winding receiving the power induced from the primary winding. The first output unit is connected to the secondary winding of the transformer, and outputs a first power current to an LED in a first operating condition. The second output unit is connected to the tertiary winding of the transformer, and outputs a second power current to the LED in a second operating condition. When the LED is connected to the power supply apparatus for LED, the power supply apparatus allows a current equal to or less than a predetermined current to flow in the LED, thereby protecting the LED from an overcurrent.

Abstract: An induction RF fluorescent lamp configuration provides reduced EMI, including a lamp envelope with a re-entrant cavity both covered on the partial vacuum side with phosphor and filled with a working gas mixture, a tubular ferromagnetic core on the non-vacuum side said re-entrant cavity wound directly on the said core with two windings having different numbers of turns, a first active winding having one end connected to an RF ballast and the other end connected to local ground, and a second passive winding having one end grounded and the other end free.

Abstract: An electronic system comprises at least a base part, a power source and at least one electronic module adapted to be powered by the power source. The base part is provided with at least two parallel extending, elongated tracks being electrically conductive. At least one parameter of the electronic module is changeable by amending the distance of the electronic module to a predetermined location on the tracks.

Abstract: Proposed is a circuit for driving a fluorescent lamp and a light-emitting diode. The circuit may include an inverter; a fluorescent lamp driving branch for driving a fluorescent lamp; a light-emitting diode driving branch for driving a light-emitting diode; a starting branch; and an alternate control branch. By using a simple circuit structure, various embodiments may realize a circuit capable of conveniently and alternately driving a fluorescent lamp and a light-emitting diode.

Abstract: A driver circuit, solid state light (SSL) source assembly including same, and a method of driving an SSL source are provided. The driver circuit includes a rectifier, an inverter, a transformer, a PFC circuit, and a frequency control. The rectifier receives an AC voltage and provides an unregulated DC voltage. The inverter includes two switches, and receives respective control signals to operate these, to generate a resonate AC signal from the unregulated DC voltage. The transformer includes a primary winding coupled to the inverter, a secondary winding to be coupled to an SSL source through an output stage, and a feedback winding. The PFC circuit controls the inverter in response to signals representative of the unregulated DC voltage and the inverter's current. The frequency control generates the control signals to control the inverter's switching frequency in response to signals representative of the output stage's current and the feedback winding's current.

Abstract: An electronic ballast for driving a light-emitting device, includes a square wave generator having a plurality of switch elements for converting a DC input voltage into a square-wave AC voltage. A transformer has a driving winding and a plurality of inductive windings mutually connected with each other, in which at least a portion of the inductive windings are respectively connected to a control terminal of the switch element. A resonant circuit connects the driving winding and a light-emitting device and converts the square-wave voltage into an AC output voltage to drive the light-emitting device. An auxiliary control unit connected to the transformer regulates a voltage waveform of the driving winding or a voltage waveform of the inductive winding according to a control signal, thereby changing the voltage waveform of the inductive winding connected to the switch element to adjust the switching frequencies of the switch elements.

Abstract: An apparatus and method for igniting a lamp during a strike mode of an inverter comprising: sequentially controlling a duty cycle sweep and a frequency sweep of driving signals in the inverter to provide an increasing output voltage to the lamp. One embodiment advantageously includes a closed feedback loop to implement the duty cycle sweep and the frequency sweep such that an open lamp voltage is reliably regulated during the strike mode. For example, the closed feedback loop stops the duty cycle sweep or the frequency sweep when the output voltage to the lamp reaches a predetermined threshold and makes adjustments to the duty cycle or frequency the driving signals as needed to keep the output voltage at approximately the predetermined threshold if the lamp has not ignited.

Abstract: Driver system and method for multiple cold-cathode fluorescent lamps and/or external-electrode fluorescent lamps. According to an embodiment, the present invention provides a system for driving a plurality of cold-cathode fluorescent lamps. The system includes a subsystem configured to receive at least a DC voltage and generate a first AC voltage in response to at least the DC voltage. The system also includes a power converter configured to receive the first AC voltage and convert the first AC voltage to at least a second AC voltage. The system further includes a plurality of current balancing devices. Each of the plurality of current balancing devices is configured to receive two currents and balance the two currents. The plurality of current balancing devices includes at least a first current balancing device, a second current balancing device, and a third current balancing device. In addition, the system includes a plurality of lamp pairs.

Abstract: An electronic system comprises at least a base part, a power source and at least one electronic module adapted to be powered by the power source. The base part is provided with at least two parallel extending, elongated tracks being electrically conductive. At least one parameter of the electronic module is changeable by amending the distance of the electronic module to a predetermined location on the tracks.

Abstract: A fluorescent lamp includes three transformers, a power supply, a converter, and four lamp tubes. The converter converts a direct current (DC) provided by the power supply into an alternating current (AC) generated in a first transformer and a second transformer for driving the four lamp tubes to emit light. The third transformer is connected to the four lamp tubes to balance working electric potentials of the four lamp tubes.

Abstract: A lamp ballast is provided requiring less size and cost for powering a discharge lamp. An inverter circuit converts a DC voltage from a DC power source into a voltage having a determined frequency, and supplies the converted voltage to the discharge lamp inserted between a pair of output ends of the inverter. A resonant circuit includes an auto-transformer and a resonant capacitor, and supplies an output voltage corresponding to a frequency of the rectangular wave voltage of the power supply circuit to the discharge lamp. A voltage detection circuit detects an output voltage of the resonant circuit based on a potential of the resonant capacitor. A control circuit has a startup control mode to set the frequency of the rectangular wave voltage based on the detected voltage from the voltage detection circuit, wherein the output voltage of the resonant circuit exceeds a starting voltage of the discharge lamp.

Abstract: In order to provide open-lamp protection to a backlight module, a pseudo open-lamp voltage is first generated according to the current flowing through a light source. If the backlight module receives a mode signal corresponding to a high contrast mode, a compensation voltage is added to the pseudo open-lamp voltage for generating a reference voltage. If the reference voltage is larger than a feedback voltage received from an input node of the light source, a driving voltage is outputted to the light source.

Abstract: An electronic ballast is disclosed, in particular for operation of gas-discharge lamps, in which a further power semiconductor is provided in addition to the conventional power semiconductor, and provides the power required for steady-state operation. This avoids the high-power MOSFET transistors, whose power losses are high, also being used for steady-state operation.

Abstract: A lamp driving circuit includes a first printed circuit board and a second printed circuit board. The first printed circuit board includes a switching unit for switching an input power source, a control unit for controlling the switching unit, an inverter transformer connected to the switching unit, and a voltage conversion unit for converting a feedback reference current for controlling an output current applied from the inverter transformer into a reference voltage and applying the reference voltage to the control unit. The voltage conversion unit is connected to the inverter transformer and the control unit. The voltage conversion unit is connected to a first feedback terminal. The second printed circuit board includes a plurality of balance coils connected to a plurality of lamps so that the same output currents are applied to the lamps, a second feedback terminal connected to the first feedback terminal, and a current conversion unit connected to the second feedback terminal.

Abstract: The present invention is to provide a ballast circuit, which includes a preheat circuit configured to perform a fixed-time, fixed-frequency preheating process on filaments at both ends of a fluorescent light tube before it is lit. While the filaments are being preheated, a power driving circuit generates an output signal whose frequency is far higher than resonant frequency of a resonant circuit, and controls the preheat circuit for enabling a filament transformer and a high-frequency coupling capacitor in the preheat circuit to couple the voltage of the output signal to the filaments and thereby preheat the filaments, but not light up the light tube. When the preheat period is up, the power driving circuit stops the preheating process and changes the frequency of the output signal to a level close to the resonant frequency, thereby oscillating the resonant circuit and generating a high voltage enough for lighting the light tube.

Abstract: The invention proposes a circuit arrangement for converting a DC voltage from a DC power supply into a pulsed voltage to operate or drive a load, for example, a DBD lamp. The circuit arrangement comprises a transformer having a primary winding and a secondary winding, a first controllable switch branch, a second controllable switch branch, and a control unit. The control unit is configured to control the first controllable switch branch and the second controllable switch branch to be alternately turned on so that at least part of the energy from the DC power supply is stored in the primary winding during each turn-on period of the first controllable switch branch and the second controllable switch branch, and to leave an idle time between the two adjacent turn-on periods so that at least part of the stored energy is transferred to the secondary winding to alternately generate a positive pulsed voltage during one idle time and a negative pulsed voltage during the next idle time.

Abstract: A backlight driving system comprises an inverter module, a current balance module, a feedback module and an open-lamp protection detection module. The inverter module provides electrical signals to a plurality of lamps. The current balance module balances currents flowing through the plurality of lamps. The feedback module detects the current of the backlight and generates a feedback signal to the invert module accordingly. The open-lamp protection detection module detects voltage variations of the feedback transformer and generates a detection signal to the inverter module accordingly. The inverter module regulates the currents flowing through the plurality of lamps according to the feedback signal and determines one or more of the plurality of lamps are faulty according to the detection signal generated by the open-lamp protection detection module, and stops providing the electrical signals to the plurality of lamps.

Abstract: The present invention relates to a lamp driving circuit capable of achieving miniaturization by using a safe insulation type multi-output transformer.

Abstract: A high-voltage discharge lamp lighting device provides a starting pulse voltage sufficient to turn on a high-voltage discharge lamp having terminal wire connections of variable length. A power conversion circuit is coupled to a commercial AC power source input and rectifies the AC input into a predetermined DC voltage output. A charging capacitor is coupled to the power conversion circuit. A full bridge circuit is coupled to the power conversion circuit and the charging capacitor and provides a rectangular wave AC output signal to a transformer primary winding circuit of at least a capacitor, a single switching element and a primary winding of a transformer. A low pulse voltage is induced in the primary winding and a transformer secondary winding is connected on one end to the high-voltage discharge lamp, wherein the low pulse voltage is stepped up to a high pulse voltage and applied to the high-voltage discharge lamp.

Abstract: A lighting device which lights the discharge lamp, includes: a converting circuit which converts the direct current into an alternating current; a pulse generating circuit which generates a high voltage pulse; and a trigger circuit which causes the pulse generating circuit to generate the high voltage pulse, wherein the pulse generating circuit includes a primary winding and a secondary winding and generates the high voltage pulse by increasing a current input to the secondary winding based on a current input to the primary winding, and the trigger circuit includes a high pass filter; a first capacitor which stores and discharges charges input via the high pass filter; and a third switching element which outputs an output current from a second capacitor connected in parallel to the converting circuit to the primary winding if an output voltage from the first capacitor exceeds a threshold.

Abstract: One aspect of the present invention is a non-electronic method of controlling the power provided to the lamp through use of multiple secondary taps off the secondary side of the HID ballast. This allows for a base capacitor to be used, along with the multiple secondary taps of the ballast, to vary the power to the lamp for purposes of providing constant light output, dimming capabilities, or to hold the power constant, or any combination of such.

Abstract: A power supply of a plasma display device includes a power source unit configured to convert a direct current source into an alternating current source, a transformer including a primary side winding electrically coupled to the power source unit and a secondary side winding having a first winding and a second winding, a sustain power supply electrically coupled to the first winding of the secondary side of the transformer, the sustain power supply configured to output a first voltage to a first voltage output terminal, and an address power supply electrically coupled to the second winding of the secondary side and serially connected to the sustain power supply, the address power supply configured to output a second voltage to a second voltage output terminal.

Abstract: A multi-lamp backlight apparatus is disclosed. The multi-lamp backlight apparatus includes 2N lamps, N balancing transformers, and a high-voltage power source. N is a positive integer and k is an integer index ranging from 1 to N. The kth balancing transformer among the N balancing transformers includes a first primary winding, a second primary winding, and a secondary winding. The first primary winding connects in series with the (2k?1)th lamp of the 2N lamps. The second primary winding connects in series with the first primary winding and the (2k)th lamp. The secondary winding corresponds to the first primary winding and the second primary winding. The high-voltage power source is connected between the first primary windings and the second primary windings.

Abstract: A single-converter circuit-based LED driver circuit (10) with isolated multi-channel outputs is disclosed. The circuit (10) includes an IC control circuit (11), a plurality of isolated output channels (70, 74) each having an output current sensing and conditioning circuit (74, 90), and an output current regulation circuit (128). The output current regulation circuit (128) includes a voltage-sensing transformer winding (T4) that senses an output voltage level across a secondary side of the circuit (10), and a peak output current sensing component (156) that senses output currents from the isolated output channels and determines which channel has a highest current output. Additionally, the circuit (10) facilitates providing output current regulation when detected output voltage is below a predetermined threshold, and providing output current regulation when the detected output voltage is above the predetermined threshold.

Abstract: A lamp drive circuit used for driving a number of lamps is provided. The lamps are used in the backlight module. The backlight module is used for providing a light source when a liquid crystal display displays. The lamps are respectively electrically connected to a coil. The coils substantially have the same coil turns and have the same magnetic circuit, so that the currents flowing through the lamps are balanced.

Abstract: The field of the invention is mainly that of light boxes used for the illumination of display screens using optical valves, notably for liquid crystal matrix displays also known as LCD screens. The light sources used are generally fluorescent tubes powered with a high voltage by devices comprising Royer electronic oscillators. These electronic oscillators do not allow wide dynamic ranges of luminance, which can be necessary for certain applications, to be easily attained. The oscillator according to the invention comprises an electronic device for discharging the stored electrical energy, said discharge device being controlled by an electronic control device using chopping modulation, thus enabling wide dynamic ranges of luminance to be attained.

Abstract: An apparatus for driving lamps and a liquid crystal display having the same, wherein the uniformity of luminance among lamps is improved, includes a main transformer unit for supplying a driving voltage to the lamps, and a balance transformer unit for making a lamp current of each of the lamps uniform. The balance transformer unit has a plurality of coils wound on a single body, and the coils have the same turns ratio and share magnetic flux so that a constant uniform current can flow through each of the coils. Accordingly, a lamp current of each of the lamps connected to the respective coils of the balance transformer unit can be maintained to be constant, and thus, the luminance of the lamp can be maintained uniformly.

Abstract: A lighting ballast (10) includes an inverter portion (12) and a resonant portion (14). During a preheat phase, a filament transformer (110) supplies preheat glow currents to lamp cathodes. Also during the preheat phase, the filament transformer boosts the oscillation frequency of the inverter portion (12) to a frequency above a resonant frequency of the resonant portion (14). Once the lamp cathodes are sufficiently heated, the filament transformer (110) is removed from the circuit and the inverter (12) is allowed to start oscillating. A feedback network (150) monitors a high frequency bus (26) and provides input to a shunt regulator (170). The shunt regulator drives the gate of a switch (128) of a bias network (126) and adds or removes the filament transformer (110) to the circuit depending on the conductive state of the switch (128).

Abstract: Disclosed are an apparatus and a method for controlling driving of a lamp. The apparatus for controlling driving of a lamp includes a plurality of lamps, a switching module for switching supplied power to output an alternating current (AC) signal, a trans-module for converting the alternating signal into high-voltage signals having different phases to supply the high-voltage signals to the lamps, an open lamp detecting module for adding low-voltage signals having different phases feedback from the trans-module to detect open states of the lamps, and a controller for controlling an operation of the switching module by a signal detected in the open lamp detecting module.

Abstract: Driver system and method for multiple cold-cathode fluorescent lamps and/or external-electrode fluorescent lamps. According to an embodiment, the present invention provides a system for driving a plurality of cold-cathode fluorescent lamps. The system includes a subsystem configured to receive at least a DC voltage and generate a first AC voltage in response to at least the DC voltage. The system also includes a power converter configured to receive the first AC voltage and convert the first AC voltage to at least a second AC voltage. The system further includes a plurality of current balancing devices. Each of the plurality of current balancing devices is configured to receive two currents and balance the two currents. The plurality of current balancing devices includes at least a first current balancing device, a second current balancing device, and a third current balancing device. In addition, the system includes a plurality of lamp pairs.

Abstract: The present invention provides a transformer apparatus configured by integrating an inverter transformer and balance transformer to be a downsized form, and a drive circuit using the transformer apparatus. The transformer apparatus comprises an inverter transformer having a core potion on which a primary coil and a secondary coil are wound, and a balance transformer having a core portion on which a primary coil and a secondary coil are wound, wherein the inverter transformer and the balance transformer are integrally formed by sharing a part of the core portions.

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

Abstract: A lamp driving circuit includes: a first voltage generator which receives a direct current power voltage and outputs a first square wave voltage in response to a first switching signal and a second switching signal having a phase inverted with respect to the first switching signal; a second voltage generator which outputs a second square wave voltage in response to a third switching signal having a phase shifted by a predetermined time with respect to the phase of the first switching signal and a fourth switching signal having a phase inverted with respect to the phase of the third switching signal; and a transformer which receives the first square wave voltage and the second square wave voltage and boosts a first driving voltage defined by an electric potential difference therebetween to a second driving voltage and applies the second driving voltage to a lamp.

Abstract: To provide a low-cost self-excited inverter driving circuit exhibiting an excellent operational efficiency. A main inverter section is so constructed that a part of output signals is fed back by a resonance loop circuit to cause a self-excited oscillation to occur in the vicinity of a resonance frequency decided by leakage inductors and capacitors on the secondary side of a high voltage transformer, thereby performing an inverter operation. It is further arranged that a halt interval setting signal, which is generated by a triangular wave forming circuit and a control section, is applied to the main inverter section, thereby halting the inverter operation in accordance with the halt interval setting signal.

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: The invention discloses a multi-lamp backlight apparatus. The multi-lamp backlight apparatus includes a first lamp, a second lamp, a controlling unit, a resonating unit, and a balance transformer. The controlling unit is used for generating a controlling signal. The resonating unit is used for converting the controlling signal into a resonating signal. The balance transformer includes a primary winding, a first secondary winding, and a second secondary winding. The primary winding is used for receiving the resonating signal. The first secondary winding is corresponding to the primary winding and coupled to the first lamp. The second secondary winding is corresponding to the primary winding and coupled to the second lamp.