| 摘要 |
PURPOSE:To prevent the breakdown of a transistor(TR) due to overvoltage, and to make the TR operate stably by connecting a speedup capacitor in parallel with a resistor. CONSTITUTION:In an inductance load driving circuit which is constituted by connecting the TR 1 interposed with a collector.emitter current route, a Zener diode 2 and the resistor 3 in series between inductance load 200 and a constant voltage source 101, and is provided with a feedback circuit connected between the collector and the base of the TR 1, the speedup capacitor 5 is connected in parallel with the resistor 3. Accordingly, at the time when a current is supplied to the base through the feedback circuit, since the speedup capacitor 5 charges quickly base parasitic capacitance, the TR 1 can be turned on at a high speed. Thus, since the overvoltage of the collector can be suppressed, the breakdown of the TR due to the overvoltage can be prevented, and the TR can be made to operate stably. |
