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Expired Canadian patentCanada

Polyphase static inverter

CA 1180750 A · Owner: Limitorque Limited · Inventors: Dumont, Gilbert C.; Dumont, Pierre-Yves

CIPO record

Overview

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

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Abstract From the Canadian patent

An electrical switching circuit for a multi-phase a.c. supply uses semiconductor rectifier switches SCR1 to 5 to reversibly switch power to a multi-phase electric motor so that the motor can be run in a forward or a reverse direction. The SCRs are provided in two sets one for switching power to forward run the motor and, the other set for reverse running of the motor. Inductor elements .DELTA. L are connected in series with the SCRs. The inductor elements comprise coils which include a non-linear permeability core, for example of ferrite or permalloy, which are operative to suppress voltage transients at switch on of the motor. These transients would otherwise produce spurious firing of 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 January 8, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 8, 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.
FiledJune 30, 1982
GrantedJanuary 8, 1985
Term endedJanuary 8, 2002
Patent numberCA 1180750 A
Classification (IPC)H02P3/20 +2 more

Timeline

Timeline From CIPO dates

1983198519871989199119931995199719992001Application filedJune 30, 1982Patent grantedJan 8, 1985Term endedJan 8, 2002

Sources & verification

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