| 摘要 |
PROBLEM TO BE SOLVED: To provide a switch circuit wherein the total loss in switching elements, at least in a large-current region, is reduced and the size thereof can be reduced. SOLUTION: A switching means 14 for controlling on/off of current is so constituted that two switching elements IGBT 14a and FET 14b, different in loss characteristic from each other, are connected in parallel. The FET 14b is smaller than the IGBT 14a in switching loss, and the IGBT 14a is smaller than the FET 14b in steady-state loss. The turn-on timing of the IGBT 14a is delayed from the turn-on timing of the FET 14b when the switching means 14 is turned on, and the turn-off timing of the FET 14b is delayed from the turn-off timing of the IGBT 14a, when the switching means 14 is turned off. Thereby the FET 14b is made to beat the switching loss and the IGBT 14a bears the steady-state loss. |
