| 摘要 |
PURPOSE:To abruptly rise the speed of an induction motor at the starting time by applying an alternating current having relatively high voltage and frequency to the motor during a short time after the starting. CONSTITUTION:When switches 7a, 7b for instructing start are closed, the set voltage of a frequency setting unit 6 is applied to an acceleration or deceleration regulator 8, and the output voltage from the regulator becomes linearly from zero volt to increased voltage. When the switch 7b is, on the other hand, closed, a signal 28 is applied from a differentiating circuit 11 to an adding point 9. Since a high voltage is applied to a voltage regulator 4 and a voltage-to-frequency converter 5 by the output of the circuit 11 after starting in this manner, the voltage and frequency of the alternating current supplied to an induction motor 1 are enhanced, and the rise of the speed of the motor can be abrupt. |
