Single phase ac synchronized motor

Abstract

There is provided a single-phase AC synchronized motor that does not need smooth of rectifier waves but stably performs shift from a starting operation to a synchronized operation. In the motor, based on detected signals of a position sensor, rectified current is reciprocally flowed to each direction of a single-phase coil which starts the motor. The motor includes a start-up operation circuit with a sensor starting period that increases a rotational speed until reaching to a first predetermined rotational speed; and a control device that controls operation of the motor as that shift to synchronized operation is performed when a rotational speed of a permanent magnetic rotor is reached to a second predetermined rotational speed nearby a synchronized rotational speed but not exceeding the synchronized rotational speed, and when the rise and fall of detected signals of the position sensor and the zero-cross point of AC current are approximately correspondent to each other.