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Expired Canadian patentCanada

Method and apparatus for controlling a blower motor in an air handling system

CA 2015509 C · Owner: Shah, Rajendra K. · Inventors: Shah, Rajendra K.

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

Apparatus and method for controlling a a motor having a stationary assembly with a plurality of winding stages for carrying motor current and further having a rotatable assembly in driving relation with a blower in an air handling system. The apparatus provides control of the blower speed over a range of static pressure variations to maintain relatively constant preselected rate of air flow in the system. The apparatus receives a preselected flow rate signal representing the preselected air flow rate. A microprocessor, responsive to both the preselected flow rate signal and a speed signal, generates a desired torque signal which is a function of both the preselected flow rate signal and 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

  • Filed April 26, 1990 and granted June 23, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 26, 2010.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 26, 2012.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledApril 26, 1990
GrantedJune 23, 1998
Term endedApril 26, 2010
Patent numberCA 2015509 C
Classification (IPC)G05D7/06 +2 more

Timeline

Timeline From CIPO dates

1991199319951997199920012003200520072009Application filedApril 26, 1990Patent grantedJune 23, 1998Term endedApril 26, 2010

Sources & verification

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