TRANSDUCER

摘要

A non-contact transducer defining a potentiometer has an elongated anti-ferromagnetic substrate (1) carrying a lower ferromagnetic layer (2), an electrically insulating layer (3), an upper ferromagnetic layer (4) and an upper, non-magnetic, electrically conductive layer (5). Layers 1 to 4 define an SDT material. The layers 2 and 4 respectively define an electrically resistive track and an electrically conductive track. The transducer also includes a magnet (6) which is movable relative to the tracks. In use, electron tunneling is possible through a localised region of the layer (3) adjacent the magnet so that such region is rendered more electrically conductive than other regions of the magnetoresistive material.