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Expired Canadian patentCanada

Electronic watthour meter

CA 2021092 C · Owner: White, Bertram · Inventors: White, Bertram; Negahban-Hagh, Mehrdad; Germer, Warren Ralph

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

An electronic watthour meter is digitally configurable to operate as several different types of watthour meters for metering electrical energy from a variety of different electric utility services. Automatic scaling of line input currents is provided to scale the voltage input to an analog to digital converter over selected ranges such that low level and high level input signals are measured in an optimum range. A digital signal processor is employed to calculate values for metered electrical energy and output pulses, each proportional to a quantum of energy flowing in the circuit being metered. The processor calculates the value of DC offset errors inherent in the various analog circuits …

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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 July 12, 1990 and granted February 15, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 12, 2010.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 12, 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.
FiledJuly 12, 1990
GrantedFebruary 15, 2000
Term endedJuly 12, 2010
Patent numberCA 2021092 C
Classification (IPC)G01R21/13 +2 more

Timeline

Timeline From CIPO dates

1991199319951997199920012003200520072009Application filedJuly 12, 1990Patent grantedFeb 15, 2000Term endedJuly 12, 2010

Sources & verification

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