CURRENT SENSOR AND MOTOR ROTATION SENSOR USING THE CURRENT SENSOR

摘要

A fail-safe current sensor and a rotation sensor of a motor using the current sensor. A first transformer (T1) for applying a high frequency signal, a second transformer (T2) for detecting the high frequency signal and a motor (1) constitute a closed circuit. The first and/or second transformer has a saturable magnetic core (C1, C2). The transformer equipped with the saturable magnetic core gets into saturation by a current flowing during the rotation of the motor, the high frequency signal from a signal generator (11) is not transmitted, and the output of a receiver (12) takes a logic value 0 for a warning. The transformer does not get into saturation when the motor is at halt, and the output of the receiver takes the logic value 1 and represents safety. The output of the receiver assumes the logic value 0 for a warning when disconnection occurs in a motor power feed line.