| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve trade-off characteristics of a surge voltage and loss without causing the enlargement or cost rise of a power converter. <P>SOLUTION: When the on-off control of a power semiconductor element is performed by an output from a PWM signal generating section 1 via an insulator 4, a pulse signal D shorter than a dead time generated from a dead time generation circuit 2 is obtained by a delay circuit 5 and a one-shot circuit 7, immediately after a turn-off command signal B; and the pulse signal is passed through an AND-circuit 8 to an OR-circuit 3 where it is superimposed on the output from the dead time generation circuit 2, thus switching gate drive conditions and varying a turn-on or a turn-off time. <P>COPYRIGHT: (C)2008,JPO&INPIT |
