Patent ID: 6324078
Filing Date: 2001-11-27
Classification: H02M,H05B

Abstract:
A power source device wherein two series circuits respectively of two switching elements are connected in parallel to a smoothing capacitor, a resonance circuit comprising at least an LC resonance circuit and a load is connected between both junction points of the switching elements in each of the two parallel circuits, a series circuit of a rectifying circuit for rectifying a source power from power source and an inductor is connected across one optional switching element in the two series circuits to employ the optional switching element as a chopper-common switching element performing a switching operation which causes a chopper circuit operation enabled, and a chopper diode is connected in inverse parallel to the other switching element series connected to the chopper-common switching element, characterized in that all switching elements are operated substantially at an equal switching frequency while respective switching elements in each series circuit are alternately turned ON and OFF, a timing of turning ON of the switching element in one of the two series circuits and connected to a low potential side of the smoothing capacitor is substantially equalized to a timing of turning ON of one switching element in the other series circuit and connected to a high potential side of the smoothing capacitor, and an ON duty ratio of at least one of the switching elements substantially equalized in the turning ON timing is reduced to lower an output to the load.