| 摘要 |
PURPOSE:To protect semiconductor elements for converting power constituting an inverter circuit from excessively large currents with a simple protective circuit. CONSTITUTION:A voltage detecting circuit 16 judges whether or not the collector-emitter voltages of transistors 10 and 11 constituting an inverter circuit exceed a reference voltage. Diodes 14 and 15 are respectively provided between the output of a reference voltage generating source 5 and the collectors of the transistors 10 and 11. When an excessively large current flows to the collector-emitter circuits of the transistors 10 and 11, the collector-emitter voltages abruptly rise and the diodes 14 and 15 are set to non-conducting states. As a result, the output of the reference voltage generating source 5 is supplied to control signal limiting circuits 8 and 9 as detecting signals. Upon receiving the detecting signals, the circuits 8 and 9 block or limit the passage of control signals supplied to the basis of the transistors 10 and 11 from control signal generating circuits 6 and 7. |
