Microcontroller Based Magnetostrictive Amorphous Wire Motor Speed Sensor

J Nderu, A Muhia, P Kihato, C Kitur


This paper presents a microcontroller based motor speed sensing approach using magnetostrictive amorphous wire. The principle operation of the sensor is based on Large Barkhausen Jump, a unique feature of the wire. The wire generates stable voltage pulses in alternating fields. These pulses correlate well with the rotary speed of the motor hence can be used to measure the speed of the motor. The pulses are signal conditioned and fed into a microcontroller for measurement of frequency. The speed of the motor is calculated from this frequency. A graphic user interface is designed where the frequency and the speed of the motor is observed on a personal computer. The design presents a motor speed sensing mechanism with desirable accuracy.


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