Patent ID: 8279629

Claim:
A switching power supply that generates a DC output voltage by conversion of an input voltage coming from a pair of input terminals, and outputs the resulting DC output voltage from a pair of output terminals, the switching power supply comprising: a transformer including a primary winding disposed on a side of the pair of input terminals, and a secondary winding disposed on a side of the pair of output terminals; a switching circuit disposed on the side of the pair of input terminals, and including first and second switching elements, first and second rectifying elements, first and second capacitive elements, and a first inductor; and a rectifying/smoothing circuit disposed on the side of the pair of output terminals, wherein a first bridge circuit is configured, in the switching circuit, by the first and second switching elements located in a diagonal arrangement, and the first and second capacitive elements also located in a diagonal arrangement, the first rectifying element is connected in parallel to the first switching element, the second rectifying element is connected in parallel to the second switching element, and one of the first and second rectifying elements is connected in forward direction and other is connected in inverse direction, the first inductor is disposed on a connection line between the pair of input terminals and the first bridge circuit, and the primary winding is connected to the first bridge circuit to form a H-bridge configuration, and the secondary winding is disposed in the rectifying/smoothing circuit.