Semiconductor electric power conversion system
CA 2012578 C · Owner: Tanaka, Chikara · Inventors: Ohno, Yasuteru; Kita, Eizo; Kawai, Tadao
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Disclosed is an improved electric power conversion system comprising a multi-phase bridge circuit composed of semiconductors such as thyristors and an associated firing circuit. It is so constructed that: if the AC input current Iac flowing in said bridge circuit is equal to or larger in value than the DC output current Idc flowing out of the bridge circuit, it will be decided that an inner defect or fault is caused and possible, expansion of inner defect will be prevented by disabling the firing circuit to extinguish said thyristors in the bridge circuit, and if the AC input current Iac is smaller than the DC output current Idc in value the, bridge is permitted to continue the operation of …
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 March 20, 1990 and granted October 4, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 20, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 20, 2012.
- 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.