Variable reluctance sensor for electromagnetically sensing the rate of movement of an object
US5229715A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 9, 1992 |
| Grant date | Jul 20, 1993 |
| Priority date | — |
| Expiry date | Oct 9, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P3/488
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A variable reluctance sensor is disclosed as adapted for sensing the rate of revolution of a toothed wheel of magnetic material. The sensor has at least two magnets disposed side by side. One of the magnet has a first pole (e.g. S pole) disposed opposite the toothed wheel, and the other magnet has a second pole (e.g. N pole) disposed opposite the toothed wheel. The second pole of the first mentioned magnet and the first pole of the second magnet are both held against a magnetic core around which a coil is wound. As the teeth of the magnetic wheel successively travel past the magnets, they create magnetic fluxes oriented in opposite directions, which counteract each other in the core. Consequently, the total magnetic flux in the magnetic member varies more greatly than heretofore depending upon whether each magnet is opposed to any one tooth, or to the space between any two neighboring teeth, of the magnetic wheel. Such great variations in magnetic flux are translated into a correspondingly large amplitude signal as by the coil around the core.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.