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Expired Canadian patentCanada

Alternating current motor control method and system

CA 1063166 A · Owner: General Electric Company · Inventors: D'Atre, John D.; Plunkett, Allan B.

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Abstract From the Canadian patent

A new and improved motor control method and system wherein the frequency of the rotating electro-magnetic flux produced in an alternating current machine, is sensed and compared to a desired value of machine flux frequency to derive an output error control signal. The output error control signal is then applied to control the frequency of the alternating current supplied to the machine in a direction and by an amount necessary to zero any difference in the sensed frequency and the desired frequency of machine flux. In preferred embodiments the actual value of the electromagnetic flux produced across the rotor-stator gap of the motor is sensed, and used as the controlling criterion in the …

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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 September 25, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 25, 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—
GrantedSeptember 25, 1979
Term endedSeptember 25, 1996
Patent numberCA 1063166 A
Classification (IPC)H02P21/10

Timeline

Timeline From CIPO dates

198019821984198619881990199219941996Patent grantedSep 25, 1979Term endedSep 25, 1996

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