| 摘要 |
PROBLEM TO BE SOLVED: To visually judge a switching element portion where anomaly has occurred, by keeping a detection signal in holding state in an abnormal drive voltage detection circuit in a drive circuit for a switching element, by detecting and displaying the detection signal in other circuit and equipment, and by providing a built-in detection circuit for main power supply and a built-in discharge circuit for electric charge. SOLUTION: If a drive voltage being applied to the gate electrode of IGBT is deviated from the set point, an abnormal drive voltage detection circuit built, in a first control circuit operates, and based on the result, a first abnormal signal holding circuit as a holding circuit of abnormal state operates. As a state when an inverter is normal, if a high potential-based voltage is applied to terminals 30, 31, an electrolytic capacitor is charged to the same voltage. Then, it is applied to a resistor 115 and a Zener diode 112, and LED 113 conducts and emits light, thereby informing of the high potential voltage of the main power supply being applied to the inverter. Upon completion of inverter operation, a charge of the capacitor is discharged while making LED conductive. |
