| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress a surge voltage and reduce a voltage applied to a switching element. <P>SOLUTION: A capacitor is connected between DC voltage terminals to which a DC voltage is inputted. Inductance means is connected between one end of the capacitor and one of load terminals. A unit switching circuit is connected in parallel to the capacitor. The unit switching circuit has a series circuit of first and second switching elements and a first coil, first and second feedback rectifier elements, and a voltage balance resistance. When the DC voltage is higher than a setting value, a both-end voltage of the capacitor is shared by non-conductive first and second switching elements. When the DC voltage is lower than the setting value, the first and second switching elements are brought into conduction periodically or as needed to output a reversed-polarity voltage to between the load terminals. In the case that the first and second switching elements are turned off, both-end voltages of the first and second switching elements are restricted by the both-end voltage of the capacitor in a period where the first and second feedback rectifier elements are in conduction. <P>COPYRIGHT: (C)2012,JPO&INPIT |
