| 摘要 |
PURPOSE:To enable to rapidly and accurately control at the prescribed position by differentiating the output of a position sensor, thereby detecting the speed of a motor at a low speed without time delay. CONSTITUTION:When a constant position stop command signal is inputted through an interface circuit 35, a position signal processor 29 is started, a speed setter 22 outputs the set speed of low value to reduce the rotating speed of a motor 7. The position signal processor 29 inputs the output of a speed detector 28 and then monitors the output signal of a head 4 when knowing that the rotating speed of the motor 7 reaches the low speed for preparing the stop, thereby shifting a switch 25 in the prescribed rotating angular range (positioning zone). As a result, the difference between the regulated output of a position regulator 24 and the motor rotating speed signal obtained by differentiating the output signal of the head 4 by a differentiator 36 is inputted to a speed regulator 26. This regulator 26 controls an inverter 30 through an inverter controller 27. |
