DC-DC CONVERTER

PROBLEM TO BE SOLVED: To provide a DC-DC converter which can shorten a rising time tr of a current of a secondary winding of a transformer, and can reduce losses in a switch element or a snubber circuit. SOLUTION: Diodes D3, D4 are connected to the secondary winding of the transformer so as to reversely oppose each other with the secondary winding between, and switches Q3, Q4 are controlled by a pulse width control circuit so as to be turned on simultaneously when either of switches Q1, Q2 is turned off. By this, a short circuit is conducted by either of passages which includes Q3 or Q4 according to the orientation of an inductance current generated at the secondary winding of the transformer. In such a way, by raising a voltage applied to the leaked inductance of the transformer by short-circuiting one terminal of the secondary winding N2 of the transformer and a central point of the terminals, the rising time tr of the current of the secondary winding of the transformer can be shortened. COPYRIGHT: (C)2008,JPO&INPIT