Speed measuring system utilizing magneto-optic switch actuated by magnetic field rotation

摘要

A Speed Sensor for a rotating member utilizes a magneto optic switch and a magnet mounted in the vicinity of the rotating member. Under normal conditions the magnetic field is at right angles to the axis of sensitivity of the switch thereby blocking light transmission through the switch. When a ferrous tooth on the rotating member passes the sensor, the magnetic field is distorted due to the change in reluctance caused by passage of the tooth thereby generating a magnetic field component along the switch axis of sensitivity turning the switch on and producing an output speed signal.