| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power conversion circuit for acquiring reverse voltage for reversely restoring a parasitic diode at low loss without requiring an additional power supply. <P>SOLUTION: A DC power source 21 outputs a DC voltage Es smaller than a DC voltage Ed. A negative pole of the power source is connected to a wiring 81 and a positive pole thereof is connected to one end of a switching element 22. The other end of the switching element 22 is connected to an anode of a diode 23, and a cathode of the diode 23 is connected to a drain of an MOSFET (i.e. a cathode of a parasitic diode 41a). Before the DC voltage Ed is applied reversely via an IGBT 31 while a forward direction current flows from the parasitic diode 41a to a coil 91, the switching diode 22 is made conductive. Thus, the parasitic diode 41a is reversely restored using the DC voltage Es via the diode 23. <P>COPYRIGHT: (C)2009,JPO&INPIT |
