Patent ID: 7405951
Filing Date: 2008-07-29
Classification: H01F,H02M

Abstract:
1. A switching power supply comprising: a first series circuit, connected to both terminals of a direct current power supply, in which a primary winding of a transformer, a reactor, and a first switch are connected in series; a second series circuit, connected to one of both terminals of the first switch and both terminals of the primary winding and the reactor, in which a second switch and a capacitor are connected in series; a smoothing circuit smoothing a voltage developed across a secondary winding of the transformer; and a control circuit alternately turning on and turning off the first and second switches, wherein the transformer, formed with a magnetic circuit includes: wherein the reactor is formed of a leakage inductance of the transformer, the leakage inductance having a value set by adjusting a number of the auxiliary cores or a length of the auxiliary cores, and wherein the plurality of auxiliary cores are provided on the transformer to leak a part of a magnetic flux generated by the main core.