Telephone line power utility circuit
CA 2097449 C · Owner: Murata Mfg Co. Ltd. · 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
In the described telephone line power utility circuit in which a direct-current, power supplied from a telephone line-side is utilized as a power source for a line terminal device by a DC-DC converter, a CPU controls over obtaining a maximum input, direct-current resistance of a DC-DC converter in a range of a predetermined standard satisfied by a direct-current resistance of the line terminal device as viewed from the, telephone line-side; the switching of the taps of a primary side winding of a transformer of the DC-DC converter for obtaining the maximum input direct-current resistance of the DC-DC converter; the duty ratio of a primary side switching element for obtaining the maximum …
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 September 15, 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.