METHOD AND APPARATUS FOR REDUCING SPIKE VOLTAGE OF SWITCHING POWER SUPPLY

摘要

A switching power supply including an input filter capacitor and a switching element according to the present invention comprises: a transformer including a transformer core, a first input winding which is wound on the transformer core and in which the flow of current is controlled by a switching operation of the switching element, a second input winding which is wound on the transformer core and in which the flow of current is controlled by a switching operation of the switching element, and an output winding which is wound on the transformer core and coupled to the first input winding and the second input winding to emit energy; an inductor; and a first capacitor, wherein the first input winding of the transformer is closely coupled to the second input winding, the inductor and the first input winding are connected in series, the first capacitor is connected between one end and the other end of the inductor and the first input winding connected in series, and the inductor and the first input winding, and the second input winding and the switching element are connected in series between two terminals of the input filter capacitor.