Patent ID: 7733053

Claim:
A charging circuit for a vehicle charger, comprising: a front high-voltage protective circuit, an input point of the front high-voltage protective circuit connected to a DC power; a first filtering circuit, an input point of the first filtering circuit connected to an output point of the front high-voltage protective circuit; a high frequency step-down switching regulator, having a first input point, a second input point, a third input point and a fourth input point, a fifth input point and an output point of the step-down switching regulator, the first input point connected to an output point of the first filtering circuit; a second filtering circuit, connected to the output point of the high frequency step-down switching regulator; a frequency modulation circuit, connected to the second input point of the high frequency step-down switching regulator; a reference voltage input circuit, connected to the third input point of the high frequency step-down switching regulator; a short-circuit protective circuit, connecting the fourth input point of the high frequency step-down switching regulator to an output point of the second filtering circuit; a sampling circuit, connecting the output point of the second filtering circuit to the fifth input point of the high frequency step-down switching regulator; a rear high-voltage protective circuit connected to the output point of the second filtering circuit; a first charging circuit, connected to an output point of the rear high-voltage protective circuit; and a second charging circuit, connected to the output point of the rear high-voltage protective circuit.