High resolution magnetoresistance sensing device with accurate placement of inducing and detecting elements

摘要

A sensing device outputs a signal which exactly corresponds to a predetermined position (angle) such as a protruding or recessed portion of a moving magnetic material member as soon as electric power to the sensing device is turned on. The sensing device includes: a magnet for generating a magnetic field; a rotary magnetic material member for changing the magnetic field generated by the magnet, the rotary magnetic material member being disposed a predetermined distance apart from the magnet; a plurality of magnetic field detecting elements which change in resistance in response to the magnetic field whose magnitude is changed by the rotary magnetic material member; wherein the plurality of magnetic field detecting elements are disposed so that the center of the gap between the magnetic field detecting elements is not coincident in location with the center of the magnet.