Accession Number : ADD017945

Title :   Magnetoresistive Linear Displacement Sensor, Angular Displacement Sensor, and Variable Resistor Using a Moving Domain Wall.

Descriptive Note : Patent, Filed 1 Oct 93, patented 12 Dec 95,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Prinz, Gary A

Report Date : 12 Dec 1995

Pagination or Media Count : 10

Abstract : A giant magnetoresistant displacement sensor includes at least one layered structure. This layered structure includes a harder magnetic (ferromagnetic or antiferromagnetic) layer having a fixed magnetic state, a second, softer, magnetic layer, and a metal layer interposed between and contacting these two layers to prevent exchange coupling between the two layers. The sensor also includes one or more indexing magnets for inducing a domain wall, at a measure and position, between regions of nonaligned magnetic fields in the softer magnetic layer; and an ohmmeter for measuring electrical resistance between points on opposite sides of the structure. In operation, the indexing magnets for inducing a domain wall are positioned relative to the giant magnetoresistant strip. The resistance across the strip is measured, and from this resistance measurement the position of the domain wall is determined. The present invention is also a variable resistor, which is operated by positioning the magnets for inducing the domain wall at a selected position, to set the resistance across the strip to a desired value.

Descriptors :   *PATENTS, *MAGNETORESISTANCE, *VARIABLE RESISTORS, MAGNETIC FIELDS, LAMINATES, DISPLACEMENT, ELECTRICAL RESISTANCE, MAGNETS, MAGNETIC DETECTORS, ELECTRICAL MEASUREMENT, ANTIFERROMAGNETISM, FERROMAGNETIC DOMAINS

Subject Categories : Electrical and Electronic Equipment
      Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE