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Expired Canadian patentCanada

Surge protection for signal transmission systems

CA 1186016 A · Owner: Nortel Networks Limited · Inventors: Chow, Peter E.K.

CIPO record

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Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

Abstract of the Disclosure, Secondary surge protection means for equipment connected to transmission lines, for example line-powered amplifiers interconnecting Tl or TlC telephone lines, includes two diode bridges and a pair of surge diverters. One diode bridge has its cathode/anode nodes connected one to each conductor of an incoming transmission line. The other diode bridge is connected in like manner to an outgoing transmission line. Each surge diverter interconnects the anode/anode node of one bridge and the cathode/cathode node of the other bridge. When a surge on one line causes the voltage across one or other diverter to exceed a predetermined threshold, the diverter conducts, …

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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 April 23, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 23, 2002.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledSeptember 23, 1982
GrantedApril 23, 1985
Term endedApril 23, 2002
Patent numberCA 1186016 A
Classification (IPC)H02H9/04 +2 more

Timeline

Timeline From CIPO dates

1983198519871989199119931995199719992001Application filedSep 23, 1982Patent grantedApril 23, 1985Term endedApril 23, 2002

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.