Current sensor
CA 2117344 C · Owner: Clarke, Ian Grainge · Inventors: Clarke, Ian Grainge
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A current sensor which makes use of the Faraday effect which is patterned on a Sagnac interferometer and which employs a coil of spun birefringent optical fibre for sensing the magnitude of current flowing through a conductor about which the sensor is, in use, located. The sensor in its preferred form comprises a coil (10) of spun single mode birefringent optical fibre (11) the, coil being arranged to locate about a conductor (12) through which current flow occurs. A beam splitting device (22) in the form of a 3*3 coupler is coupled with the ends of the coil fibre and is arranged to launch counter-propagating light beams into the respective ends of the coil fibre. A lasing light source (16) …
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed December 22, 1992 and granted April 24, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 22, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 22, 2014.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.