Dc current sensor
CA 2100135 C · Owner: Kawakami, Makoto · Inventors: Kawakami, Makoto; Yamaguchi, Shigeru
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention is directed to a DC current sensor which comprises a detecting core of an annular soft magnetic material, and a detecting coil wound in a toroidal shape around the detecting core. A wire to be detected is positioned through the detecting core and powered with a DC current. The DC current sensor includes means for periodically forming a magnetic gap at a portion of the detecting core by magnetic flux generated substantially perpendicularly against a circumferential magnetic flux generated in the detecting core by DC current flowing through the wire. The DC current sensor of the present invention is used in a DC leakage breaker. It has a simple construction and a good …
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 July 8, 1993 and granted November 4, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 8, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 8, 2015.
- 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.