Gate turnoff thyristor control circuit with shorted gate detection
CA 2071890 A1 · Owner: Brown, Herbert Joseph · Inventors: Brown, Herbert Joseph; Bailey, Ronald Barry
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
For responding to a shorted gate in a gate turnoff thyristor (71) the gate electrode of which is connected by means of a controllable switch (89) to a control voltage terminal having a negative potential with respect to the cathode potential of the thyristor the controllable switch (89) being arranged to conduct negative gate current in response to a thyristor turnoff command voltage, comparing means (127) is coupled to the controllable switch for detecting when the switch is conducting negative gate current of relatively high magnitude, timing means (117) is active for a predetermined interval following the start of said thyristor turnoff command, and logic means (100) operative to cause …
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 19, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended July 19, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 19, 2013.
- 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.