Patent ID: 8223519

Claim:
A power control system connected between an alternating current (AC) power supply and an electronic device, the power control system comprising: a rectifier circuit, wherein a first terminal of the rectifier circuit is connected to the AC power supply, the rectifier circuit converts an alternating current signal of the AC power supply to a first direct current (DC) voltage; a buck circuit, wherein a first terminal of the buck circuit is connected to a second terminal of the rectifier circuit, the buck circuit receives the first DC voltage and outputs a second DC voltage, the voltage of the second DC voltage is less than the voltage of the first DC voltage; a voltage divider circuit, wherein a first terminal of the voltage divider circuit is connected to the second terminal of the rectifier circuit; a control circuit, wherein a first terminal of the control circuit is connected to a second terminal of the buck circuit, a second terminal of the control circuit is connected to a second terminal of the voltage divider circuit, the control circuit detects the voltage of the first DC voltage via the voltage divider circuit and compares the voltage of the first DC voltage with a standard voltage and outputs a control signal with a third terminal; and a switch circuit, wherein a first terminal of the switch circuit is connected to the third terminal of the control circuit, a second terminal of the switch circuit is connected to the AC power supply, a third terminal of the switch circuit is connected to the electronic device, a fourth terminal of the switch circuit is connected to the second terminal of the buck circuit, the control circuit controls the switch circuit to connect the AC power supply to the electronic device according to the control signal of the control circuit.