| 摘要 |
PURPOSE: To provide a motor drive circuit for extracting an electrical energy with a relatively high voltage level from a motor immediately when the motor is deactivated. CONSTITUTION: When the supply voltage of a motor drive circuit 9 fails, an emergency control signal is generated by a signal generator 36, an external power supply circuit for extracting an electrical energy from a motor is activated, and an extraction energy is supplied to an external circuit 8. The external power supply circuit has a commutation circuit that is formed of flyback diodes 25c, 25d, 26c, 26d, 27c, and 27d for bridging switches 25a, 25b, 26a, 26b, 27a, and 27b of a commutation circuit. The drive circuit has short-circuiting switches 25e, 26e, and 27e for bridging stator coil windings 25, 26, and 27. A short- circuiting means 37 temporarily and intermittently short-circuit the stator coil windings 25, 26, and 27 according to the emergency control signal. A capacitor 32 is charged. An energy charged to the capacitor 32 is used to feed power to an external circuit 8 temporarily as soon as power supply to the drive circuit fails. |
