| 摘要 |
PURPOSE:To decrease the turn-on loss, by triggering a gate turn-off thyristor with a gate circuit of large power added to another gate circuit, detecting the delay in the rduction of applied voltge and increasing the gate current. CONSTITUTION:A forward voltage 46 is applied to a GTO31 in triggering the GTO31. A turn-on reference 41 goes to +15V at a time t6, a transistor of photocouplers 38, 40 is conductive, then a normal gate current 47 determined with a resistor 35 starts flowing, and the GTO31 enters turning-on. When the gate current is deficient, and the turning-on is delayed, a voltage 48 of a capacitor 44 reaches a Zener voltage 49 of a Zener diode 45, a photothyristor coupler 32 is conductive, a gate current determined with a resistor 37 and a capacitor 36 is superimposed on the normal gate current, the turning-on of the GTO is quickened, allowing to reduce the turning-on loss of the GTO31. |
