Ground fault circuit interrupter with immunity to wide band noise
CA 2132136 C · Owner: Mackenzie, Raymond W. · Inventors: Engel, Joseph C.; Mackenzie, Raymond W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In a ground fault circuit interrupter in which it was found that wide band noise induced by load transients is rectified by an op-amp In the detector, circuit, false trips due to the wide band noise are eliminated by only comparing the, output of the amplifier with a threshold of opposite polarity to that of the rectified, noise signal and by eliminating capacitive coupling between the current sensor and, the op amp. This requires an op amp with a low offset on the order of about , five, percent or less.
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 September 14, 1994 and granted March 11, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 14, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 14, 2016.
- 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.