| 摘要 |
PURPOSE:To prevent damage of an output circuit when an inverter pump is locked, by stopping production of output from the output circuit when it is detected that the voltage between the drain and the source of an MOS type field- effect transistor (MOS FET) is higher than a prescribed value. CONSTITUTION:An inverter circuit for an inverter pump of this invention is composed of a DC power source 1, a switching circuit 2, an output circuit 3 having switches of MOS type field-effect transistors (called hereinafter MOS FET), an AC motor 4 and a stop circuit 6 which detects the voltage drop VDS between the drain and the source of an MOS FET 3h in synchronism with energization of the MOS FET 3h and gives a signal to the switching circuit 2 to stop the output of the output circuit 3 when it is detected that the voltage drop VDS is greater than a prescribed value. With such an arrangement, MOS FETs in the output circuit 3 can be protected against burn-out even if the inverter pump is used under unexpectedly unfavorable conditions. |
