Displacement sensor including a magnetically responsive member and a pair of piezoelectric elements

摘要

A displacement sensor is provided with first and second piezoelectric elements, a pair of electrodes at one and the other ends of each of the first and the second piezoelectric elements; a permanent magnet mechanically fixed to one end of the first piezoelectric element; a small piece mechanically fixed to one end of the second piezoelectric element and having almost the same weight as that of the permanent magnet; and a base plate to which the other ends of the first and the second piezoelectric elements are mechanically fixed; wherein the electrodes provided at the other end of each of the first and the second piezoelectric elements are electrically connected, and the electrodes provided at one end of each of the first and the second piezoelectric elements are used as output terminals. Also, a pair of small pieces made of a magnetic material and a non-magnetic material can be used instead of the above permanent magnet and small piece.