| 摘要 |
PROBLEM TO BE SOLVED: To obtain an overcurrent protective circuit by which a main transistor at an inverter controller is operated at the maximum breakdown strength of the main transistor. SOLUTION: The collector-emitter voltage Vce of a main transistor 3 is detected by voltage-dividing resistances 10, 11, and the collector current Ic of the main transistor 3 is detected by a current detection resistance 13. When the collector current Ic of the main transistor 3 becomes a prescribed value or higher, an overcurrent protective circuit controls, on the basis of a breakdown strength according to the collector-emitter voltage Vce of the main transistor 3 at this time, the time in which the main transistor 3 is turned off so as to be protected. |
