| 摘要 |
PURPOSE:To inhibit overvoltage in the forward direction while miniaturizing a clamping circuit and improving efficiency by forming the clamping circuit clamping the voltage of the capacitor of a snapper circuit within predetermined value so as to be directed to the forward direction to an SCR. CONSTITUTION:Clamping diodes 51, 52 are connected in polarity which discharges charging voltage, which is directed toward the forward direction to the gate-turnoff thyristor GTO of the capacitors 36 from the series nodes of the diodes 35 and capacitors 36 of the snapper circuit, toward a power supply 1. Clamping diode currents are decelerated in a short time by setting the sum of the forward voltage drops of the diodes 51, 52 and snapper diodes 351, 352 to value larger than the forward voltage drop of a free wheel diode 4. Accordingly, the forward direction voltage of the GTO can be inhibited, and the GTO device can be miniaturized and efficiency is improved. |
