| 摘要 |
PURPOSE:To perform a protecting function with a power converter having small size and weight without reactor by providing a transistor on a power supply line, and detecting the overcurrent at a malfunction time by the transistor. CONSTITUTION:A parallel circuit of a transistor 10 and a diode 11 is provided between a power source 1 and an inverter bridge 4. A level detector 6' detects a voltage VCE between the collector and the emitter of the transistor 10, outputs a signal (a) in response to the detected value, and applies it to an AND gate 8. The signal (a) of the detector 6' is set too become ''1'' at normal operation time, but to become ''0'' when an overcurrent is detected at the malfunction time. As a result, the output signal (c) of the gate 8 becomes ''0'' irrespective of the output signal (b) of a controller 7, and a drive circuit 9 turns OFF IGTs 41-46. Thus, it can prevent an overcurrent from flowing the IGTs at the malfunction time. |
