| 摘要 |
PURPOSE:To obtain an overvoltage limit circuit where the limit effect of an overvoltage can be obtained even if high-speed switching is performed and a surge current when limiting overvoltage is large. CONSTITUTION:An overvoltage limit circuit 11 when a self arc-extinguishing semiconductor device (for example, IGBT) which is serially connected to a main DC power supply 3 and an inductance (transformer) 2 for turning on or off the current through an inductance consists of a series circuit made of an avalanche diode 12 and a silicon surge absorber 13 which is serially connected to the anode. The avalanche diode of the series circuit is connected to a non-grounding main terminal (drain terminal) of a self arc-extinguishing type semiconductor device and a silicon surge absorber is connected to a control terminal (gate terminal). |
