| 摘要 |
PURPOSE:To reduce a rotational speed variation by causing a frequency transfer function from a load torque variation to said rotational speed variation to be zero or to an extremely small value in a particular frequency group and by improving said transfer function also in other frequencies. CONSTITUTION:A compensating means 4 produces a control signal (c) operating according to a detected signal (b) of a speed detector 3 to drive a motor 1 by a power amplifier 8. A rotational error-computing means in the compensating means 4 obtains a digital rotational error operating according to a detected digital signal of the speed detector 3 for every detecting action of said speed detector 3. The compensating means 4 performs actions of the rotational error- computing means and a control signal-producing means prior to those of a stored value-preserving means, immediately after the speed detector 3 has obtained a new detected digital signal. Also, the stored value-preserving means is switched so as to practice its action or not to do so according to the results of the judgement of a stable-state judging means. |
