Patent ID: 8085016

Claim:
A power supply circuit, comprising: a voltage output controller comprising a first switching element and a second switching element; a standby controller, comprising a trigger and a third switching element, the trigger comprising an input terminal and an output terminal; a standby detection circuit configured for detecting a mode of a load, the standby detection circuit comprising an input terminal and two output terminals; and a microprocessor comprising a first input terminal, a second input terminal, and an output terminal; wherein each of the first, second, and third switching elements comprises an input terminal, an output terminal, and a control terminal, each input terminal of the second and the third switching elements being applied with a direct current voltage, the input terminal of the first switching element being connected to ground, the output terminal of the first switching element being connected to the control terminal of the second switching element, the control terminal of the first switching element being connected to the output terminal of the third switching element, the output terminal of the second switching element being connected to the load, and the first input terminal of the microprocessor, the input terminal of the standby detection circuit being connected to the load, the two output terminals of the standby detection circuit being connected to an input terminal of the microprocessor and the input terminal of the trigger, the output terminal of the trigger being connected to the control terminal of the third switching element and the input terminal of the microprocessor, wherein when the input terminal of the standby detection circuit detects the load entering an active mode from a power off mode, the standby detection circuit sends a control signal to the trigger, the trigger generating a voltage to turn on the third switching element, the direct current voltage being applied to the first switching element via the third switching element, the first and the second switching elements being turned on sequentially, the direct current voltage being applied to the load and the microprocessor via the second switching element, wherein when the standby detection circuit detects the load entering a standby mode from the active mode, the standby detection circuit sends another control signal to the microprocessor, the microprocessor controlling the third switching element, and the first and the second switching elements to be turned off sequentially such that power is restricted from reaching the load and the microprocessor, the power supply circuit being in the standby mode.