| 摘要 |
PURPOSE:To change a rotational frequency quickly and stably, and to realize a fast access time by detecting the change of a speed control signal and generating an acceleration signal or a deceleration signal. CONSTITUTION:In as rotational frequency controller for a DC motor whose rotational frequency is variable, means 10, 12, 13 detecting the level of a speed control output at the time of the transition of the rotational frequency and outputting an acceleration signal S15 and a deceleration signal S16 are provided. Means 14, 15, 19 detecting the level of a phase control output and outputting a rotational frequency lock signal S3 are furnished. A circuit detecting the levels of the speed control output and the phase control output is constituted by using comparators 12, 13, 14, 15. Consequently, the acceleration signal S15 and the deceleration signal S16 are generated on the transition of the rotational frequency. Accordingly, the transition time is shortened, thus shortening the access time. |
