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Expired Canadian patentCanada

Control circuits, electronically commutated motor systems and methods

CA 1301240 C · Owner: Patel, Amritlal Hirdas · Inventors: Patel, Amritlal Hirdas; Erdman, David Marvin; Beatty, James Andrew

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 Control circuit for an electronically commutated motor which has a rotatable assembly and further has a stationary assembly with a plurality of winding stages having terminals for energization, and switches for applying a voltage to one or more of the terminals of the winding stages at a time and commutating the winding stages in a preselected sequence to rotate the rotatable assembly. A preselected sequence of winding stages are left correspondingly unpowered so that a plurality of the winding stages are unpowered at some time. The winding stages generate back emf signals and also couple electrical signals from each energized winding stage to the unpowered winding stages which …

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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 May 19, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended May 19, 2009.
  • 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 28, 1989
GrantedMay 19, 1992
Term endedMay 19, 2009
Patent numberCA 1301240 C
Classification (IPC)H02P6/00

Timeline

Timeline From CIPO dates

1990199219941996199820002002200420062008Application filedSep 28, 1989Patent grantedMay 19, 1992Term endedMay 19, 2009

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