Magneto-optic current sensor
US4947107A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 28, 1988 |
| Grant date | Aug 7, 1990 |
| Priority date | — |
| Expiry date | Jun 28, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/0322
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A sensor (10) for sensing the magnitude of current flowing in a conductor (12) based upon the Faraday effect is disclosed. The invention utilizes a magneto-optic material having one or more layers (32) in which alignment with an optical fiber is not critical in achieving accurate current measurements. A magneto-optic material (28) in accordance with the invention includes one or more layers (32) each having a substrate having opposed surfaces coated with a material exhibiting the Faraday effect in which light from a light source is transmitted through the magneto-optic element without substantial internal reflection and is incident upon a surface area of the coating which is greater than the surface area of the beam of light. Furthermore, the invention measures the magnitude of current flowing in the conductor accurately by utilizing null detection for a first range of current values from zero to a first magnitude having either of two possible polarities and measures a second range of current values extending from the first magnitude to a second magnitude having either of the two possible polarities in which null detection is not utilized. By not utilizing null detection for the se…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.