| 摘要 |
PURPOSE:To enable reduction of a loss due to charging and discharging of snubber capacitors even when high-frequency switching is executed and thereby to enable removal of the restriction on a minimum ON time, by providing a semiconductor value constructed of non-latch semiconductor devices connected in series or in series-parallel and a parallel snubber circuit having a clipping function. CONSTITUTION:A semiconductor valve 51 is constructed of non-latch semiconductor devices 61, gate drivers 62 of the devices 61, diodes 63, snubber capacitors 64, snubber resistors 65 and resistors 67. A circuit composed of the capacitors 64 and the resistors 65 and 66 constitutes a parallel snubber circuit having a clipping function. Accordingly, the capacitance of the capacitors 64 can be made small, since it is determined on the basis of an internal loss of the devices 61 and the balance of a thermal capacity of the resistors 66. Although an overvoltage is impressed on one of the devices 61 due to a difference in switching between the devices 61 at the time of turn-OFF, it is clipped to be a safe value by the resistors 66 having the clipping function.
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