Optic switch and speed sensor
US4843232A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 28, 1987 |
| Grant date | Jun 27, 1989 |
| Priority date | — |
| Expiry date | Dec 28, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P3/487
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An electro-optic speed sensor for sensing the speed of rotation of a rotating sending unit which includes an optical switch transducer for sensing disturbances in a magnetic field caused by the passage of a rotating magnetic sending wheel on the rotating member. The optical switch transducer uses a Faraday material and provides its signal by rotating the polarity of polarized light from a first source of light having a first bandwidth while allowing a second source of light having a second bandwidth to pass through unaffected. The first and second sources of light are thereafter, reflected within the transducer. The disturbances in the magnetic field generate an optical signal resulting from changes in the Faraday rotation. A photodetector receives the light from the first source to develop an operational signal corresponding to the speed of rotation of the rotating member and light from the second source to check on the continuity of the sensor system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.