| 摘要 |
PURPOSE:To miniaturize a motor, thereby reducing cost and enable it to be applied also for high speed rotation, by making a rotary transformer for exciting field magnetic poles, of soft ferrite, and by forming position-detecting signal into a sinusoidal wave. CONSTITUTION:A rotary transformer for exciting an armature 7 having poles N, S alternately is formed with cores 2a-3b made of soft ferrite wound up with exciting coils 4a, 4b. By utilizing the rotary transformer, sine-wave-formed rotor-position-detecting signal is obtained. The position-detecting signal is compared with the armature current detecting value of the corresponding phase. When the armature current detecting value is larger than a position-detecting signal value by a set value, then armature current is cut off and magnetic storage energy is discharged as armature current, and when the armature current detecting value is smaller than the position-detecting signal value by the set value, then armature current is contrived to be conducted. |
