Patent ID: 7848127

Claim:
A direct-current power supply apparatus comprising: a reactor; a first rectification circuit including a pair of first input terminals connected to an alternating-current power supply by the reactor, a plurality of first diodes which rectify a voltage applied to the first input terminals, and first positive side and first negative side output terminals which output a voltage rectified by the first diodes, the first positive side output terminal being connected to one end of a load; a second rectification circuit including a pair of second input terminals connected to the alternating-current power supply by the reactor, a plurality of second diodes which rectify a voltage applied to the second input terminals, and second positive side and second negative side output terminals which output a voltage rectified by the second diodes, the second negative side output terminal being connected to the other end of the load; a switch element connected between the second positive side output terminal of the second rectification circuit and the first negative side output terminal of the first rectification circuit, and which constitutes a short-circuit path for the alternating-current power supply, together with the reactor, one of the second diodes of the second rectification circuit and one of the first diodes of the first rectification circuit; and a control unit which turns on the switch element for a short time after the voltage of the alternating-current power supply has passed zero-crossing point, thereby forming the short-circuit path; wherein the first rectification circuit conducts current from the alternating-current power supply to one end of the load via one of the first input terminals, one of the first diodes, and the first positive side output terminal; and the second rectification circuit conducts current from the other end of the load to the alternating-current power supply via the second negative side output terminal, one of the second diodes, and one of the second input terminals.