Abstract: Disclosed is a LED DC control circuit that comprises an AC to DC circuit, a voltage division circuit, a controller and a logic circuit. The AC to DC circuit receives an AC reference voltage and generates a sine wave reference voltage and a DC reference voltage. The voltage division circuit receives the DC reference voltage and generates a threshold voltage. The controller compares the threshold voltage with the DC reference voltage to generate an inner reference voltage. The controller receives a first PWM voltage signal to accordingly sample the inner reference voltage and then output a second PWM voltage signal. The logic circuit receives the second PWM voltage signal to generate a driving voltage and a load current for driving a power switch circuit. Within each period of the sine wave reference voltage, at least one of the driving signals of the load current is a relative maximum.

Abstract: An LED drive circuit comprises a power supply unit, a first LED lamp string, a first voltage control unit, a second LED lamp string and a first power transfer unit. The power supply unit outputs a drive power to drive the first LED lamp string. The first voltage control unit gets the drive power and stabilizes and provides the voltage to the first LED lamp string. The first voltage control unit includes a power switch where the drive power generates a power loss. The second LED lamp string and first power transfer unit are coupled in series with the first voltage control unit so that the power loss is transferred and output to drive the second LED lamp string. Thus loss of the drive power is reduced and lighting efficiency of the LED improves.

Abstract: An LED drive circuit comprises a power supply unit, a first LED lamp string, a first voltage control unit, a second LED lamp string and a first power transfer unit. The power supply unit outputs a drive power to drive the first LED lamp string. The first voltage control unit gets the drive power and stabilizes and provides the voltage to the first LED lamp string. The first voltage control unit includes a power switch where the drive power generates a power loss. The second LED lamp string and first power transfer unit are coupled in series with the first voltage control unit so that the power loss is transferred and output to drive the second LED lamp string. Thus loss of the drive power is reduced and lighting efficiency of the LED improves.

Abstract: A signal regulator module includes a floating current regulator, a signal sensor, and a feedback controller. The floating current regulator is electrically coupled to a driving circuit and the light sources of a display panel for regulating the driving signals based on a feedback signal in a photo couple means. The signal sensor is electrically coupled to the floating current regulator for generating a corresponding voltage signal based on the driving signal through a photo couple means. The feedback controller is electrically coupled to the signal sensor and the floating current regulator for generating the feedback signal based on the voltage signal and outputting the feedback signal to the floating current regulator.

Abstract: A lamp drive circuit used for driving a number of lamps is provided. The lamps are used in a 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 have the same number of turns and have the same magnetic circuit, so that the currents flowing through the lamps are balanced.

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: A liquid crystal display includes a plurality of light sources of different colors and a control device. The control device is used to control the light sources to emit light with different duty cycles. Through persistence of vision, light generated by the light sources will form an image of desired colors. White balance can be achieved by controlling the duty cycles.

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 during a liquid crystal display displays. The lamps are respectively electrically connected to a coil is. 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 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 active current regulator circuit. In one embodiment, the active current regulator circuit includes a first input node for receiving a first reference electrical signal, a second input node for receiving a second reference electrical signal, a ground node, and an output node for outputting an output electrical signal with respect to the ground node. The active current regulator circuit further includes a PI controller having a first input node, a second input node, and an output node, and a linear regulator having a first input node electrically coupled to the output of the PI controller for receiving a voltage signal V0 generated the PI controller, a first output node and a second output node. In operation the voltage signal V0 is responsive to at least one input voltage signal applied to the first input of the second input of the amplifier, and drives the linear regulator to have a controlled electrical signal at its first output node accordingly.

Abstract: An inverter unit including a converter, a transformer, a feedback circuit and an open lamp lock circuit is provided. The converter receives a drive signal, and outputs a duty voltage signal accordingly. The transformer is selectively coupled with a lamp of a display panel module, and receives the duty voltage signal. When the transformer is coupled with the lamp, the transformer outputs an output voltage to the lamp according to the duty voltage signal to light up the lamp. The feedback circuit receives a feedback signal from the lamp, and outputs a feedback voltage signal accordingly. The open lamp lock circuit is coupled with the feedback circuit, receives a control signal, selectively receives the feedback voltage signal, and disables the drive signal selectively according to the feedback voltage signal and the control signal.

Abstract: A signal regulator module includes a floating current regulator, a signal sensor, and a feedback controller. The floating current regulator is electrically coupled to a driving circuit and the light sources of a display panel for regulating the driving signals based on a feedback signal in a photo couple means. The signal sensor is electrically coupled to the floating current regulator for generating a corresponding voltage signal based on the driving signal through a photo couple means. The feedback controller is electrically coupled to the signal sensor and the floating current regulator for generating the feedback signal based on the voltage signal and outputting the feedback signal to the floating current regulator.

Abstract: A driving circuit uses a plurality of transformers to provide currents for driving a plurality of LEDs associated with a plurality of current paths. Each transformer has two induction coils with a coil turn ratio between to the number of turns in each induction coil. One induction coil is used to provide an output current to a different current path and the other induction coil is connected to the corresponding induction coil of other transformers for forming a current loop. The output current of each transformer has a relationship with the output current of the other transformers depending on the coil turn ratios of the connected transformers. LEDs in red, blue and green colors can be connected to different current paths so that the brightness of the LEDs in each color can be determined by the current in a current path.

Abstract: An inverter unit including a converter, a transformer, a feedback circuit and an open lamp lock circuit is provided. The converter receives a drive signal, and outputs a duty voltage signal accordingly. The transformer is selectively coupled with a lamp of a display panel module, and receives the duty voltage signal. When the transformer is coupled with the lamp, the transformer outputs an output voltage to the lamp according to the duty voltage signal to light up the lamp. The feedback circuit receives a feedback signal from the lamp, and outputs a feedback voltage signal accordingly. The open lamp lock circuit is coupled with the feedback circuit, receives a control signal, selectively receives the feedback voltage signal, and disables the drive signal selectively according to the feedback voltage signal and the control signal.

Abstract: A liquid crystal display capable of reducing current leakage includes a printed circuit board, a plurality of light sources, a power controller disposed on the printed circuit board, a bridge converter disposed on the printer circuit board, a first transformer, a second transformer, and a liquid crystal panel. The plurality of light sources are used for generating light, and each light source includes a first end and a second end. The power controller is used for generating power driving signal. The bridge converter is used for generating a supply voltage signal based on the power driving signal. The first transformer is used for transforming the supply voltage signal into a first operating signal to each first end of the plurality of light sources. The second transformer is used for transforming the supply voltage signal into a second operating signal to each second end of the plurality of light sources.

Abstract: An active current regulator circuit. In one embodiment, the active current regulator circuit includes a first input node for receiving a first reference electrical signal, a second input node for receiving a second reference electrical signal, a ground node, and an output node for outputting an output electrical signal with respect to the ground node. The active current regulator circuit further includes a PI controller having a first input node, a second input node, and an output node, and a linear regulator having a first input node electrically coupled to the output of the PI controller for receiving a voltage signal V0 generated the PI controller, a first output node and a second output node. In operation the voltage signal V0 is responsive to at least one input voltage signal applied to the first input of the second input of the amplifier, and drives the linear regulator to have a controlled electrical signal at its first output node accordingly.

Abstract: A floating driving device for illumination includes a illumination unit having a first terminal and a second terminal. A first driver is electrically coupled to the first terminal of the illumination unit, for applying AC voltages to the first terminal. A second driver is electrically coupled to the second terminal of the illumination unit, for applying AC voltages to the second terminal in such a manner that the AC voltages at the first terminal and the second terminal are out of phase.

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 during a liquid crystal display displays. The lamps are respectively electrically connected to a coil is. 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 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: A liquid crystal display includes a plurality of light sources of different colors and a control device. The control device is used to control the light sources to emit light with different duty cycles. Through persistence of vision, light generated by the light sources will form an image of desired colors. White balance can be achieved by controlling the duty cycles.