Patent ID: 8004114

Claim:
A two-stage power supply system having a standby power supply mode and a normal power supply mode, comprising: a standby power circuit, for receiving an alternating current (AC) power and perform voltage step-down on the AC power so as to generate a standby AC power; a driver, for outputting a termination signal when in the standby power supply mode, and outputting a drive signal when in the normal power supply mode; a main power circuit, coupled to the driver and controlled by the drive signal, for performing voltage step-down on the AC power so as to generate a main AC power; a rectifier, coupled to the standby power circuit and the main power circuit, the rectifier is for rectifying the standby AC power into a standby DC power when in the standby power supply mode, and for rectifying an integrated power of the standby AC power and the main AC power into a supply DC power when in the normal power supply mode; a direct current (DC) voltage step-down circuit, coupled to the rectifier, the DC voltage step-down circuit is for providing voltage step-down on the standby DC power when in the standby power supply mode, and providing voltage step-down on the supply DC power when in the normal power supply mode; and a voltage regulator circuit, coupled to the DC voltage circuit and a load, the voltage regulator circuit providing the standby DC power to the load after voltage stabilization and voltage step-down when in the standby power supply mode, and providing the supply DC power to the load after voltage stabilization and voltage step-down when in the normal power supply mode.