Magnetoresistive position sensor including an encoder wherein the

Abstract

In a preferred embodiment, a magnetoresistive (MR) position sensor, including: a rotatable cylindrical encoder wheel having a plurality of alternating N and S magnetic poles spaced a constant pole pitch around the circumferential surface of the encoder wheel, adjacent ones of the N and S poles having interfacing edges parallel to the axis of rotation of the encoder wheel; a first MR sensing array disposed on an insulative substrate in proximity to the circumferential surface of the encoder wheel, such as to sense rotating magnetic fields produced by the N and S poles as they pass the first MR sensing array as the encoder wheel rotates, the first MR sensing array including at least a first section comprising at least two legs extending parallel to the interfacing edges, the at least two legs being joined in series so as to form a serpentine shape; apparatus to apply a constant DC voltage across terminal ends of the serpentine shape.