Effect of Length and Position Relative to the Rotor of the Magnetostrictive Amorphous Wire in Motor Speed Sensing

Abstract

The performance of the magnetostrictive amorphous wire in motor speed sensing has been shown to match that of conventional motor speed sensors. The sensor is based on Large Barkhausen Jump, a unique feature of the wire, which occurs at a given critical length of the wire. A permanent magnet is also used and therefore depending on the strength of the magnet used, the position of the sensor relative to the rotor is expected to influence the results. This paper presents experimental results on the influence of length and position of the magnetostrictive amorphous wire on the performance of the sensor. A close observation on the signal waveforms indicate that there is a critical length and optimal positioning of the wire from the magnet for which the performance of the sensor is satisfactory

Keywords:  Length, Magnetostrictive Amorphous Wire, Position, Speed sensing