| 摘要 |
PURPOSE:To attain turn-on/turn-off surely with less gate power by providing an MOSFET driven by the same gate signal between the gate and cathode of each auxiliary GTO. CONSTITUTION:The MOSFET 16 is connected between the gate and source of the auxiliary GTO 12 and the MOSFET 17 is connected between the gate and source of the auxiliary GTO 13. A main GTO 11 is turned off by an off-gate circuit composing of a switch element 14 and a gate power supply 15. An off- gate signal from a gate signal generator 18 is fed to the gate of the FETs 16, 17 to short-circuit the gate and cathode of the auxiliary GTOs 12, 13 at the same time. Since the off-gate circuit of the main GTO is not used in common with that of the auxiliary GTO in this case, the maximum turn-off current of the main GTO is not lowered. Thus, sure turn-off, turn-on is attained with less gate power. |
