Ac supervisory signal detector
CA 1160779 A · Owner: Gte Automatic Electric Incorporated · Inventors: Brush, Douglas J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An AC supervisory signal detector circuit for use in conjunction with a trunk circuit of a PABX telephone system connected to a telephone central office. Valid AC supervisory signals are detected to the exclusion of noise signals and response time for detection of termination of AC supervisory signals is improved.
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
- Granted January 17, 1984. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 17, 2001.
- 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.