Temperature stable proximity sensor with sensing of flux emanating from the lateral surface of a magnet
US4970463A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 13, 1989 |
| Grant date | Nov 13, 1990 |
| Priority date | — |
| Expiry date | Mar 13, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/08
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A ferrous object sensor assembly is capable of sensing the presence or absence of an object of high magnetic permeability, such as a tooth or notch on a rotatably mounted ferrous wheel at zero speed and immediately upon power-up and, thus, may also be used as a proximity sensor. The ferrous object sensor assembly is comprised of a permanent magnet and a magnetic flux responsive sensor having a sensing plane which produces an electrical output signal which varies as a function of the change in magnetic flux density. The ferrous body sensor assembly does not rely upon pole face magnetism as some known conventional sensors but, rather, relies upon a the radial component of magnetic flux density emanating from a lateral surface of the magnet, intermediate opposing pole faces. Since the ferrous object sensor assembly does not rely on pole face magnetism, its electrical output signal is relatively stable over a relatively wide temperature range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.