Passive non-contact amorphous speed sensor

A new non-contact speed sensor is presented using Metglas 2605SC amorphous ribbon material. The proposed sensor is spontaneously magnetised by permanent magnets fixed on a rotating shaft. The rotation of the magnets causes a signal to be induced in the sensor search coil. The amplitude and frequency of the signal are directly proportional to the speed of the rotation of the shaft. The sensor is then annealed to improve its linearity and sensitivity in both the digital and analogue formats. Two more speed sensors have been constructed from silicon-Iron and Nickel-Iron. The amorphous speed sensor has been favourable compared to these devices.