Patent ID: 7167383
Filing Date: 2007-01-23
Classification: H02M,Y02B

Abstract:
1. A step-up/down voltage chopper having a first series circuit of a first main transistor and a first main diode, which is connected across a DC input voltage circuit, a filter capacitor and a second series circuit of a second main diode and a second main transistor, which is also connected across an output load side and a filter reactor, which is connected between the juncture between the first main transistor and the first main diode in the first series circuit and the juncture between the second main diode and the second main transistor in the second series circuit, wherein: a first and a second resonant capacitor in effect are connected between the collector and the emitter of the first and second main transistors, respectively, and in operation other than that with a small load current the first and second main transistors are turned off with the collector current therein caused to flow through the first and second resonant capacitor, respectively, for soft switching.