Switching device for controlling thyristors
CA 2197376 C · Owner: Koyama, Kenichi · Inventors: Koyama, Kenichi; Yamamoto, Hiroshi; Sasao, Hiroyuki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A switching device has a control section to transfer a gate control signal indicating thyristors from ON state to OFF state after a parallel switch is open and an opening degree of the parallel switch is satisfied where no arc discharge is generated at a contact point in the parallel switch.
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 February 12, 1997 and granted November 14, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 12, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 12, 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.
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.