| 摘要 |
PURPOSE:To increase the dV/dt rating between the collector and the emitter and to reduce the switching loss, by giving a reverse bias between the base and emiter, when a main transistor (TR) in an inverter using TRs is nonconductive. CONSTITUTION:When pulse transformers 18, 28 are not driven, no current flows to diodes 30, 40, 31, 41, a TR59 is nonconductive, the base current of a TR58 flows to turn on the TR58, and the base and emitter of a main TR2 is back-biased. When he pulse transformers 18, 28 are driven, a current flows to the diodee 30, 40, 31, 41, and a base current flows to the TR59, resulting in turning on the TR59 and turning off the TR58. Thus, a TR2 is forward-biased to be conductive. In this case, if a pulse transformer is not driven, the TR58 is conductive and the base and emitter of the TR2 is back-baised, then it is quickly nonconductive. The current from the collector to the base due to the capacitance between the collector and the emitter capaictance between the collector and the emitter capacitance caused by the increase in a voltage between the collector and emitter flows to the TR58, allowing to reduce the current flowing to the TR2. |
