Patent ID: 8711588

Claim:
A power supply device, comprising: an alternating current (AC) power supply unit supplying a first primary current in a positive half cycle and supplying a second primary current in a negative half cycle; a transformer unit including a first transformer transforming the first primary current from the AC power supply unit into a first secondary current, and a second transformer transforming the second primary current from the AC power supply unit into a second secondary current; a main switch unit including a first main switch controlling the first primary current flowing through a primary winding of the first transformer, and a second main switch controlling the second primary current flowing through a primary winding of the second transformer; an auxiliary switch unit including a first auxiliary switch forming a transfer path for surplus power present before the first main switch is turned on, and a second auxiliary switch forming a transfer path for surplus power present before the second main switch is turned on; an auxiliary inductor unit including a first auxiliary inductor adjusting an amount of current flowing through the first auxiliary switch during a switching operation of the first auxiliary switch, and a second auxiliary inductor adjusting an amount of current flowing through the second auxiliary switch during a switching operation of the second auxiliary switch; and a path providing unit providing a conduction path based on power supplied from the AC power supply unit.