High power dc blocking device for ac and fault current grounding
CA 2183176 C · Owner: Pelly, Brian R. · Inventors: Pelly, Brian R.; Tachick, Henry N.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A high power DC blocking device is provided which blocks DC current passes AC current, and limits the voltage across it under fault conditions. A DC blocking capacitor is used to block the flow of DC current while allowing the passage of normal AC currents. A main bypass path includes switching devices which provide a low impedance path across the capacitor under fault conditions. Auxiliary switching devices are used to connect a storage capacitor across the device at the initiation of a fault thereby charging the storage capacitor to a stored voltage level before the main switching devices are fired. After the fault passes the auxiliary switching devices are fired once again to apply the …
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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 August 12, 1996 and granted October 24, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 12, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 12, 2018.
- 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.