DETECTING CIRCUIT FOR MAGNETOSTRICTIVE ELEMENT

摘要

PURPOSE:To attain always a stable detection sensitivity and to simplify a circuit constitution, by detecting simultaneously the amplitude change and the phase change of a differential voltage corresponding to the strain applied to a magnetostrictive element of a bridge circuit. CONSTITUTION:An AC bridge circuit where coils L1 and L2 wound around a magnetic material having the reverse magnetostrictive effect are used as measuring sides, reference voltage circuits 11-13 which divide an AC voltage 7 connected to the input side of this bridge circuit to generate a reference voltage, and a multiplier 14 which multiplies the differential voltage of the output voltage of the bridge circuit and the reference voltage are provided. The amplitude change and the phase change of the differential voltage are detected simultaneously.