| 摘要 |
PURPOSE:To perform the stable operation without regard to the magnitude of the starting load by obtaining the phase difference between the output of a frequency accelerator and the counter electromotive voltage pulses of the motor, and changing the counter electromotive voltage pulses and the output pulses of the frequency accelerator. CONSTITUTION:The frequency accelerator gives the output of a counter C1, to which the constant-frequency pulses are applied, to inverters G1-G3. The frequency of an output OUT is increased with the elapse of time via switches S1-S3 which are independently switched by a signal X and an AND gate G4. Then, the frequency of the output OUT is divided by a counter C6 and applied to a ring counter R. Thus, a synchronous signal which drives the motor is obtained. Then, the phase difference with respect to a rotor-position pulse signal B, which is obtained by the counter electromotive voltage during the acceleration of the motor, is obtained. The synchronous operation of the motor is changed to the normal operation. Therefore, the synchronous operation period is minimized even during the starting load is large, and the stable starting can be accomplished. |
