| 摘要 |
PURPOSE:To increase efficiency of a synchronous motor by a method wherein the size of the current supplied to the motor is controlled according to the difference determined by detecting and then comparing the permanent magnet rotor rotation phase and the phase of the current or voltage applied to the motor. CONSTITUTION:A sinusoidal wave current is applied to a stator coil main winding 8. The rotating magnetic field generated by a current that runs in the auxiliary winding 9 causes a permanent magnet rotor 1 to rotate. A magnetic field sensing device 5 detects the rotation phase B of the permanent magnet rotor 1 and said rotation phase B is compared in a phase comparator 11 with the phase A of the current supplied to the motor, and the size of load torque is determined. A voltage whose size corresponds to the difference between the rotation phase B and the phase A of the current supplied to the motor is applied, for example, to the base of a control transistor 12, thereby regulating the size of the current to be applied to the motor. |
