Ground skew protection method and apparatus
CA 2229073 C · Owner: Mccartney, Thomas · Inventors: Mccartney, Thomas; Fish, Laurence H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method and apparatus are provided for protecting a non-isolated data communications cable against ground skew used with an AC power source. A current summing transformer (20) is coupled to an AC power source. The current summing transformer includes a single transformer core (20A) and a plurality of coils. One of the coils is connected in series with each phase neutral (if , present) and ground line in the AC power source. The plurality of coils are substantially identical. Each coil has an identical number of turns and an identical direction of winding on the transformer core (20A). The current summing transformer (20) is only needed in the power path to one of two or more …
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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 January 14, 1997 and granted April 23, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 14, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 14, 2019.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.