| 摘要 |
PURPOSE:To obtain a semiconductor motor capable of self-starting and removing all Hall elements for detecting the position by utilizing as a position detection signal the counterelectromotive force detection signal of an armature coil and using a logic circuit. CONSTITUTION:When an armature coil is rotated to receive reverse energization, the output 22a of an operational amplifier becomes a curve 38a, its terminal 28a becomes ''H'', its terminal becomes ''L'', and the energization is continued. When the counterelectromotive force becomes zero due to rotation, the output of a comparator 26a becomes ''L'', terminals 28a, 28b become ''L'', and the energization of the armature coil is interrupted. The output of the operational amplifier becomes a curve 38b in the further rotation, the terminals 28a, 28b respectively become ''L'', ''H'', positive energization is performed at the armature coil, and the rotation is continued. The self-starting is carried out by a drive pulse signal obtained through a ring counter 30 and a distributor 31 operated at the prescribed rotating speed or lower from the output pulse of an oscillator 29. |
