| 摘要 |
<P>PROBLEM TO BE SOLVED: To overcome the problem in which when current flowing through a switching element S*# is rapidly increased by switching the switching element S*# to ON state, a clamp circuit having a Zener Diode 40 and a switching element 42 for clamp can be too late to take a countermeasure against a rapid rise of current going through the switching element S*#. <P>SOLUTION: The drive circuit comprises: a DC voltage source 25; a switching element 27 for constant current; a DC voltage source 22; and a switching element 23 for fixed voltage. According to an ON manipulation command for turning on a switching element S*#, a gate of the switching element S*# is first charged while using, as a power source, the DC voltage source 25 whose terminal voltage is made a voltage VL for restriction, and the switching element 27 for constant current. Then, after a given length of time has elapsed, the gate of the switching element S*# is charged while using, as a power source, the DC voltage source 22 whose terminal voltage is made a voltage VH(>VL) for steadying, and the switching element 23 for fixed voltage. <P>COPYRIGHT: (C)2012,JPO&INPIT |
