Patent ID: 8339808
Filing Date: 2012-12-25
Classification: H01F,H02M

Abstract:
1. A switching power supply unit converting a DC input voltage inputted from an input terminal pair into a DC output voltage, and outputting the generated DC output voltage from an output terminal pair, the switching power supply unit comprising: a transformer including: an inverter circuit arranged between the input terminal pair and the primary winding, and including switching elements; and a rectifying-smoothing circuit arranged between the output terminal pair and the first and second secondary windings, and including first and second rectifying elements, first to third choke coils, and a capacitive element arranged between the output terminal pair; wherein the first rectifying element is arranged between a first junction and one end of the capacitive element, the first junction being defined as a junction of one end of the first secondary winding and one end of the second choke coil; the second rectifying element is arranged between a second junction and the one end of the capacitive element, the second junction being defined as a junction of one end of the second secondary winding and one end of the third choke coil; a third junction is connected to the one end of the first choke coil, the third junction being defined as a junction of the other end of the first secondary winding and the other end of second secondary winding; and a fourth junction is connected to the other end of the capacitive element, the fourth junction being defined as a junction of the other end of the first choke coil, the other end of the second choke coil and the other end of the third choke coil.