| 摘要 |
PURPOSE:To rapidly switch from high to low speed for a DC motor by starting a constant speed control at low speed control at low speed of the motor when the real speed for regenerative braking the motor is lowered than the low speed specified speed in case the motor is switched from high to low speed. CONSTITUTION:When a real speed of a DC motor is faster than a specified speed, a speed control signal VFS becomes a high level, while when the real speed is lower than the specified speed, the speed control signal VFS becomes a low level. A motor control circuit 13 controls the motor 1 in response to the speed control signal VFS. When the motor 1 is switched from high to low speed, the specified speed is altered and a run signal STA is turned off. Thus, the motor 1 is regneratively braked to abruptly decelerate the speed of the motor 1. Thereafter, when the fall of the speed control signal VFS is detected, the run signal STC is turned on to control constant speed of the motor 1. |
