Method and apparatus for detecting the linear or rotary position of an object through the use of a variable magnetic shunt disposed in parallel with a yoke air gap

摘要

A position detecting apparatus includes a permanent magnet which is operative to generate a magnetic field and a yoke which is provided in electromagnetic communication with the permanent magnet for guiding at least a portion of the magnetic field therethrough. The yoke includes a high-permeability magnetic material and has an air gap of predetermined lateral dimension. A variable magnetic shunt is affixed to an object whose position is sought to be detected. The magnetic field in the air gap is perturbed by the movement of the shunt causing a change in intensity measurable by a magnetoresistive sensor. The sensor generates an electrical signal which corresponds to the determined intensity of the magnetic field and to the angular/linear position of the variable shunt and the attached object.