| 摘要 |
PROBLEM TO BE SOLVED: To improve the reliability by the multiplification while pulses having small widths are suppressed by a method wherein minimum pulse width regulators are provided in three systems to generate signals from which pulses having small widths are eliminated and a majority operation is performed by a majority decision circuit. SOLUTION: Small width on-pulses which cause the device breakdown of a GTO are eliminated by a minimum pulse width regulator 140-1 from a pulse signal A4 which is outputted from a pulse generator 130-1 and a pulse signal A5 is outputted. A timing regulator 150-1 outputs an ignition pulse signal A6 whose on-timing and off-timing are regulated for the respective GTO's so as to turn on and turn off the GTO's connected to one arm simultaneously. The ignition pulse signals A6, B6 and C6 which are outputted from the timing regulators 150-1, 150-2 and 150-3 are inputted to a majority circuit-2 160 in which the majority operation is performed to output an ignition pulse signal 180. As a result, the reliability can be improved while the small width on-pulses are suppressed. |
