Signal separation circuit
CA 2097448 C · Owner: Sakuragi, Satosi · Inventors: Sakuragi, Satosi; Kuroda, Takashi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A signal separation circuit for separating direct current power on a telephone with a transistor. A CPU, which includes an A/D converter is connected to detect theemitter-collector voltage of the transistor and to control the base current of the transistor to maintain the emitter-collector voltage constant.
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 June 1, 1993 and granted August 4, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 1, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 1, 2015.
- 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.