Abstract: An exemplary inverter circuit (200) includes a direct current (DC) input terminal (210); a transformer (230) including a first primary winding (231) and a second primary winding (232); a first switch transistor (240); a second switch transistor (250); a pulse generator (260) providing pulse driving signals to the first switch transistor and the second transistor respectively; and a resistor (29). The first primary winding and the second primary winding share a tap (235), the tap is connected to the DC input terminal via the resistor. A drain electrode of the first switch transistor is connected to the tap via the first primary winding, and a drain electrode of the second switch transistor is connected to the tap via the second primary winding.

Abstract: An exemplary printed circuit board (2) includes a substrate (21) and a printed circuit (20) formed on the substrate. The printed circuit includes a first input wire (210) and a ground wire (230). The first input wire includes at least one tip and the ground wire includes at least one tip facing the at least one tip of the first input wire. Each of the tips of the first input wire and the ground wire defines a pointed end.

Abstract: An exemplary backlight control circuit (200) includes a DC power supply (VDD), a load circuit (210), an input circuit (230), and a PWM IC (250). The load circuit includes two light sources (2113, 2114) and a rectifier and filter circuit (213). The input circuit includes a diode (231) and a capacitor (237). The PWM IC includes a current sampling pin (251) and an overvoltage protection pin (253). A low voltage terminal of a first one of the two light sources is connected to the current sampling pin via the rectifier and filter circuit, and a low voltage terminal of a second one of the two light sources is connected to a cathode of the diode. An anode of the diode is connected to the DC power supply and grounded via the capacitor. The overvoltage protection pin is connected to the DC power supply.

Abstract: An exemplary backlight control circuit (20) includes: at least two load circuits (210), a pulse width modulation integrated circuit (PWM IC) (250) having a current sampling pin (251), a switching circuit (270), and an input circuit (230). Each load circuit includes a backlight and a backlight inspecting circuit having an output end. The switching circuit includes a first transistor which includes a source electrode connected to ground, a drain electrode connected to the current sampling pin, a gate electrode connected to a power supply. The input circuit includes at least two first diodes, at least two input resistor, a second transistor, and a pink-to-pink detector circuit. The pink-to-pink detector circuit includes a second diode, a second bias resistor, and a second filter capacitor. Each output end of the load circuits is connected to the gate electrode of the second transistor via the input resistor, the first and second diode.

Abstract: An exemplary backlight driving circuit (20) includes a first pulse generator (230), a second pulse generator (240), a transformer (250) having a primary winding (251), a first transistor (210), a second transistor (220), and a first capacitor (290). The first transistor is a P-MOSFET. The first transistor includes a gate electrode (211) connected to the first pulse generator, and a drain electrode (213) connected to a first terminal (252) of the primary winding. The second transistor is an N-MOSFET. The second transistor includes a gate electrode (221) connected to the second pulse generator, a source electrode (222) connected to ground, and a drain electrode (223) connected to the first terminal of the primary winding. The first capacitor includes one terminal connected to a second terminal of the primary winding.

Abstract: An exemplary backlight driving circuit (20) a first power supply (260); a second power supply (270); a signal output terminal (280); an AND gate (210); a follower (220); a capacitor (290); a reverser (230); a first transistor (240), which is a N-Channel mode metal-oxide-semiconductor field-effect transistor (N-MOSFET), having a gate electrode connected to an output end of the AND gate through the follower, a source electrode connected to the signal output terminal, a drain electrode connected to the first power supply; and a second transistor (250), which is a N-Channel mode metal-oxide-semiconductor field-effect transistor (N-MOSFET), having a gate electrode connected to the output end of the AND gate through the reverser, a source electrode connected to the ground, a drain electrode connected to the signal output terminal.

Abstract: An exemplary backlight modulation circuit (200) includes a pulse generator circuit (210) configured for generating a first square pulse; a voltage division circuit (230) configured for receiving the first square pulse and generating a second square pulse according to the first square pulse; an oscillator circuit (240) configured for generating a reference voltage; and an amplifier (200) comprising a negative input configured for receiving the second square pulse from the voltage division circuit, and a positive input configured for receiving the reference voltage from the oscillator circuit as a reference pulse signal, the amplifier being configured for generating a backlight adjusting signal according to the reference pulse signal and the second square pulse.

Abstract: An exemplary backlight control circuit (20) includes at least two sampling circuits (21), at least two feedback circuits (22), and a PWM IC (23). Each of the sampling circuits includes a sampling output (210) and a backlight lamp (211). The PWM IC includes a current sense pin (230). The at least two feedback circuits correspond to the at least two sampling circuits, respectively. Each of the feedback circuits includes a resistor (222) and a diode (223) electrically coupled in parallel. The sampling output is configured to output a first voltage when the backlight lamp is in a normal working state, and output a second voltage when the backlight lamp has an open circuit. One terminal of the diode is electrically coupled to the sampling output of a corresponding one of the sampling circuits, and an opposite terminal of the diode is electrically coupled to the current sense pin.

Abstract: An exemplary pulse driving circuit (200) includes a pulse generator (210) configured for generating a pulse signal for driving the pulse driving circuit; a capacitor (220); an NMOS (negative metal-oxide semiconductor) transistor (230) comprising a gate electrode configured to be connected to the pulse generator via the capacitor, a drain electrode configured to be connected to a load circuit, and a source electrode configured to be connected to a DC (direct current) power supply (270); a current limiting resistor (240) connected between the gate electrode and the source electrode of the NMOS transistor; and a diode (250) comprising a positive terminal connected to the source electrode of the NMOS transistor and a negative terminal connected to the gate electrode of the NMOS transistor.

Abstract: An LCD backlight driving circuit is provided for providing protection to LCD backlight lamps. In a preferred embodiment, the driving circuit for LCD backlight lamps comprises: a PWM controller sending control signals; two transistors receiving the control signals and sending two low-voltage pulse signals; an inverter converting the two low-voltage pulse signals to a high-voltage AC (Alternating Current) power; two lamps; two overvoltage protection circuits connected to the two lamps respectively; a voltage feedback module connected to the two lamps, a current feedback module connected to one of the two lamps; and a double-bridge circuit connected between the two lamps, and connected to the current feedback module for controlling the PWM controller to turn-on or turn-off. The driving circuit is capable of providing defective connection protection and open-circuit protection to LCD backlight lamps, and proportionately adjusting current flowing through the lamps.

Abstract: An LCD backlight driving circuit is provided for providing protection to LCD backlight lamps. In a preferred embodiment, the driving circuit for LCD backlight lamps comprises: a PWM controller sending control signals; two transistors receiving the control signals and sending two low-voltage pulse signals; an inverter converting the two low-voltage pulse signals to a high-voltage AC (Alternating Current) power; two lamps; two overvoltage protection circuits connected to the two lamps respectively; a voltage feedback module connected to the two lamps, a current feedback module connected to one of the two lamps; and a double-bridge circuit connected between the two lamps, and connected to the current feedback module for controlling the PWM controller to turn-on or turn-off. The driving circuit is capable of providing defective connection protection and open-circuit protection to LCD backlight lamps, and proportionately adjusting current flowing through the lamps.