摘要:
An exemplary power supply circuit (20) includes a first commutating and filter circuit (21), a transformer (24), a second commutating and filter circuit (25), a transistor (27), a pulse width modulation circuit (26) outputting a control signal to control operation state of the transistor, and a feedback circuit (29). An external alternating current voltage is converted into a direct current with a cooperation operating of the transistor, the first commutating and filter circuit, the transformer, and the second commutating and filter circuit. The feedback circuit feeds an operating state of the transformer back to the pulse width modulation circuit, and the pulse width modulation circuit outputs corresponding control signals to turn on or turn off the transistor.
摘要:
An open protection circuit (300) for a backlight module includes a PWM (350) with a control port (351) to disable the PWM. A switch (371) has a gate and a source connected to the control port. A plurality of first input circuits (330) includes first diodes (331), each of which has a first positive terminal connected to the gate and a negative terminal connected to ground. A plurality of second input circuits (340) include input resistors (341) connected to the control port. A plurality of detecting circuits (310, 380) are connected to the fluorescent lamps (311) and the first and second input circuits respectively. Each detecting circuit includes a sampling resistor (313) connected to one of the negative terminals of the first diodes, thereby the control port of the PWM is pulled low when either one of the fluorescent lamps are open-circuit.
摘要:
An open protection circuit (300) for a backlight module includes a PWM (350) with a control port (351) to disable the PWM. A switch (371) has a gate and a source connected to the control port. A plurality of first input circuits (330) includes first diodes (331), each of which has a first positive terminal connected to the gate and a negative terminal connected to ground. A plurality of second input circuits (340) include input resistors (341) connected to the control port. A plurality of detecting circuits (310, 380) are connected to the fluorescent lamps (311) and the first and second input circuits respectively. Each detecting circuit includes a sampling resistor (313) connected to one of the negative terminals of the first diodes, thereby the control port of the PWM is pulled low when either one of the fluorescent lamps are open-circuit.
摘要:
An exemplary multiplexed direct current regulation output circuit (2) includes a feedback circuit (22), a sampling circuit (30), a power control chip (21), a first output (27), a second output (28), a first half wave rectifier circuit (23), a second half wave rectifier circuit (24), a first filter circuit (25), a second filter circuit (26), a transformer (20), and a balance control circuit (29). The transformer is configured to provide low voltages to the first output via the first half wave rectifier circuit and the first filter circuit in series, and provide high voltages to the second output via the second half wave rectifier circuit and the second filter circuit in series. The balance control circuit is configured to control a voltage at the second output.
摘要:
An exemplary power supply circuit (20) includes a first commutating and filter circuit (21), a transformer (24), a second commutating and filter circuit (25), a transistor (27), a pulse width modulation circuit (26) outputting a control signal to control operation state of the transistor, and a feedback circuit (29). An external alternating current voltage is converted into a direct current with a cooperation operating of the transistor, the first commutating and filter circuit, the transformer, and the second commutating and filter circuit. The feedback circuit feeds an operating state of the transformer back to the pulse width modulation circuit, and the pulse width modulation circuit outputs corresponding control signals to turn on or turn off the transistor.
摘要:
An exemplary multiplexed direct current regulation output circuit (2) includes a feedback circuit (22), a sampling circuit (30), a power control chip (21), a first output (27), a second output (28), a first half wave rectifier circuit (23), a second half wave rectifier circuit (24), a first filter circuit (25), a second filter circuit (26), a transformer (20), and a balance control circuit (29). The transformer is configured to provide low voltages to the first output via the first half wave rectifier circuit and the first filter circuit in series, and provide high voltages to the second output via the second half wave rectifier circuit and the second filter circuit in series. The balance control circuit is configured to control a voltage at the second output.
摘要:
An exemplary power supply control circuit (200) includes a first port (201), a second port (202), a third port (203), a controllable switch (280), and a control circuit (270). The first and second ports are configured to receive a power supply voltage signal. The second and third ports are configured to output the power supply voltage signal to a load circuit. The controllable switch includes a control member (281) and a switch member (282). The control circuit is configured to control a working state of the control member. When the load circuit stops working, the control circuit controls the control member to control the switch member to be disconnected, so as to cut off the power supply voltage signal from outputting to the load circuit. A liquid crystal display (400) using the power supply control circuit is also provided.
摘要:
An exemplary multiplexed DC voltage regulation output circuit (2) comprises a first output circuit, a second output circuit, a transformer (21), a power control chip (22), a feedback circuit (20), and a control circuit (26). The first output circuit is configured for outputting low voltage. The second output circuit is configured for outputting high voltage. The transformer is configured for outputting voltages to the first output circuit and the second output circuit. The feedback circuit feeds composite signals from the first output circuit and the second output circuit back to the power control chip. The power control chip adjusts the output voltages of the transformer by changing impulse width of voltages transmitted into the transformer in accordance with the composite signals. The control circuit controls the output voltage of the second output circuit back to a normal high voltage when the output voltage is higher than normal.
摘要:
An exemplary flat panel display includes a back cover having a receiving space, and conductive wires accommodated in the receiving space. The back cover includes an inner surface corresponding to the receiving space. Typically, plural fixing elements for fastening the conductive wires are arranged on the inner surface, which can secure the conductive wires on the back cover.
摘要:
An exemplary power supply circuit (20) includes a scaler (21), a field-effect transistor (23), a pulse width modulation circuit (25), and a capacitor (29). The scaler includes an output port (213). The pulse width modulation circuit includes an input port (251). The input port of the pulse width modulation circuit is grounded via the capacitor. The field-effect transistor includes a gate electrode (231), a source electrode (232), and a drain electrode (233). The gate electrode is connected to the output port of the scaler. The source electrode is grounded. The drain electrode is connected to the input port of the pulse width modulation circuit.