| 摘要 |
Disclosed is a motor speed control system, in which a detected induced voltage of a motor under speed control is compared with a velocity reference signal which is a sawtooth wave voltage synchronized with a power supply frequency. The motor speed control system comprises a control circuit having a thyristor for controlling the energization of the motor, a sawtooth wave generator circuit for generating the sawtooth wave voltage, an induced voltage detection circuit for detecting the induced voltage due to the rotation of the motor and storing the detected induced voltage in a capacitor, a limiter circuit for limiting a charge voltage of the capacitor, a comparator circuit for comparing the detection signal from the induced voltage detection circuit with the sawtooth wave from the sawtooth wave generator circuit, and a pulse generator circuit for generating a trigger pulse for the thyristor. The motor speed control system reduces the operation noise of the motor, reduces the variation of the motor speed and shortens the response time. |
