| 摘要 |
PURPOSE:To prevent FETs constituting a three-phase inverter from being damaged due to improper operation of a gate control circuit when a power supply voltage becomes extremely low and hence a short-circuiting accident. CONSTITUTION:A malfunction prevention circuit 50 with a Zener diode 40 which is connected so that current is shut off when a power supply voltage is lower than a predetermined reference voltage is provided, thus forcing a group of corresponding FETs Q1, Q3, and Q5 or Q2, Q4, and Q6 of each phase out of a plurality of FETs where the malfunction prevention circuit 50 constitutes a three-phase bridge inverter circuit to be off when the power supply voltage is lower than the reference voltage. |
