Abstract:
The present teaching relates to a magnetic sensor that comprises a housing, an input port and an output port, both extending from the housing and the input port being connected to an external alternating current (AC) power supply, and an electrical circuit. The electrical circuit comprises an output control circuit coupled with the output port and configured to be responsive to a magnetic induction signal to control the magnetic sensor to operate in a state in which a load current flows through the output port when a predetermined condition is satisfied, and operate in another state when the predetermined condition is not satisfied. The operating frequency of the magnetic sensor is positively proportional to the frequency of the external AC power supply.
Abstract:
A motor driving circuit drives a motor. The motor driving circuit includes a controllable bidirectional alternate current switch, a sensor, a rotation direction control circuit and a switch control circuit. The controllable bidirectional alternate current switch is connected to the motor and an alternate current power supply. The sensor detects a magnetic pole position of a rotor. The rotation direction control circuit controls a current flowing direction through a power supply terminal and a ground terminal of the sensor responsive to rotation direction set of the motor, to determine a phase of a detection signal outputted at an output terminal of the sensor. The switch control circuit controls a switch state of the controllable bidirectional alternate current switch to determine a rotation direction of the motor responsive to the detection signal and a polarity of the alternate current power supply.