Patent ID: 6717399
Filing Date: 2004-04-06
Classification: G01B,G01D

Abstract:
A magnetic incremental motion detection system with offset compensation, comprising,a target wheel having a plurality of uniformly circumferentially spaced indications adjoined thereto; a magnetic sensor positioned adjacent said target wheel with an air gap therebetween; a linear amplifier having first and second inputs, said first amplifier input connected to said magnetic sensor; and a low-pass filter connected between said magnetic sensor and said second input of said amplifier; a signal comparison stage connected to said amplifier for producing a digital signal in response to an analog output signal of said amplifier; and wherein said magnetic sensor is a magnetoresistive sensor comprising a half-bridge magnetoresistive sensor including first and second magnetoresistive elements connected in series, the junction between said elements being connected to said first amplifier input and to said low-pass filter.