Apparatus or method for sensing a magnetic field; sensor for reading information from a magnetic storage medium; magnetoresistive element; switch controlled by a magnetic field.

摘要

An apparatus for sensing a change in a magnetic field is disclosed. The apparatus includes a giant magnetoresistive element (20) positioned adjacent to the magnetic field (36). First, second, and third electrical contacts (30A-30C) are spatially positioned on the giant magnetoresistive element (20) forming a first current path having a first variable resistance between the first (30A) and second (30B) electrical contacts and a second current path having a second variable resistance between the first (30A) and third (30C) electrical contacts. The movable magnetic field (36) causes a change in the first variable resistance in the first current path when the field (36) becomes positioned substantially underneath the first current path, and the magnetic field (36) causes a change in the second variable resistance in the second current path when the field (36) becomes positioned substantially underneath the second current path.