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Expired Canadian patentCanada

Active hybrid circuit

CA 1047659 A · Owner: Western Electric Company, Incorporated · Inventors: Elder, Joseph M. (Jr.)

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 This specification discloses a time division communication system having a plurality of line circuits for coupling telephones over bidirectional lines to outgoing and incoming time division buses. Each of the line circuits comprises an active hybrid having separate transmit and receive operational amplifiers for connecting the outgoing and incoming buses to a telephone line via interface circuitry and during selected time slots of a time division frame. The interface circuitry comprises transformer and capacitor arrangements for coupling a bidirectional telephone line via a filter to an input of the hybrid transmit amplifier and an output of the receive amplifier. …

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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 January 30, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 30, 1996.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Filed—
GrantedJanuary 30, 1979
Term endedJanuary 30, 1996
Patent numberCA 1047659 A
Classification (IPC)H04H20/67 +2 more

Timeline

Timeline From CIPO dates

198019821984198619881990199219941996Patent grantedJan 30, 1979Term endedJan 30, 1996

Sources & verification

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