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Expired Canadian patentCanada

Transistor pair temperature sensor

CA 1048622 A · Owner: National Semiconductor Corporation · Inventors: Dobkin, Robert C.

CIPO record

Overview

Drawings and full text

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

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Abstract From the Canadian patent

A temperature sensor includes a pair of transistors each connected in series with a respective one of a pair of resistors across a source of voltage. The emitters of the transistors are connected together and the collectors are connected to a respective input of a differential amplifier. An output of the amplifier drives a voltage divider circuit having a pair of outputs each connected to the base of a respective one of the transistors. The transistors are operated at different current densities and the ratio of such current densities is maintained constant with changes in temperature by feedback from the amplifier which has an output which is porportional to absolute temperature. In a …

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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 February 13, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 13, 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—
GrantedFebruary 13, 1979
Term endedFebruary 13, 1996
Patent numberCA 1048622 A
Classification (IPC)G01K7/00 +1 more

Timeline

Timeline From CIPO dates

198019821984198619881990199219941996Patent grantedFeb 13, 1979Term endedFeb 13, 1996

Sources & verification

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