| 摘要 |
PURPOSE: To prevent a vibration, noise and a step out by switching discontinuous/continuous rotation in accordance with a rotational speed. CONSTITUTION: As a comparing result in a speed comparator 3, in the case that a speed signal v (t) is less than a speed corresponding to a threshold speed vth , a signal switch 7a prepares switching a changeover switch 8a for outputting a rectangular wave signal Y1 (t) to an a-phase side of a current converter 10, and in the case that the speed signal v (t) is the speed or more corresponding to the threshold speed vth , prepares switching the changeover switch 8a for outputting a sinusoidal wave signal X1 (t) to the a-phase side of the current converter 10. A signal value comparator 9a compares signal intensity of the sinusoidal wave signal X1 (t) with that of the rectangular wave signal Y1 (t), and switches the changeover switch 8a only in the case of agreeing. |
