Transformer-coupled line interface circuit
CA 2321401 A1 · Owner: Cramm, Colin H. · Inventors: Cramm, Colin H.; Hupe, Gerard J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A line interface circuit has two windings of a transformer coupled via feed resistors to a telephone line. A feedback loop, responsive to differential voltage sensed at junction points between the feed resistors and the transformer, provides a feedback signal to a third winding of the transformer to compensate for characteristics of the transformer. Another feedback loop, responsive to signal current through the feed resistors, provides another feedback signal to the third winding of the transformer for presenting a desired impedance of the line interface circuit to the telephone line.
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 September 28, 2000. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 28, 2020.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 28, 2022.
- 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.