Magnetoresistive position sensor including an encoder wherein the magnetization extends greater than 0.5 times the pole pitch below the surface
US5545985A · kind A · utility
Inventor
Key dates
| Filing date | Mar 16, 1994 |
| Grant date | Aug 13, 1996 |
| Priority date | — |
| Expiry date | Mar 16, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/145
- WIPO fieldMeasurement
- WIPO sectorInstruments
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.