Patent Yard Sign in
Expired Canadian patentCanada

Method of and circuit for ohmmeter calibration

CA 1283445 C · Owner: Eccleston, Larry E. · Inventors: Eccleston, Larry E.

CIPO record

Overview

Drawings and full text

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

Open the CIPO record

Abstract From the Canadian patent

Abstract of the Disclosure, The calibrator of an ohmmeter is compensated to eliminate any error as a result of the resistance of leads interconnecting terminals of the ohmmeter and a reference resistance to which the ohmmeter is connected during calibration. In accordance with one aspect of the invention, ohmmeter current flowing through a buffer amplifier biased by a floating power supply bypasses the ohmmeter leads. In accordance with another aspect a, current equal in magnitude but opposite in direction to the ohmmeter current is applied to the leads.

Read the whole patent

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 April 23, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 23, 2008.
  • 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 22, 1988
GrantedApril 23, 1991
Term endedApril 23, 2008
Patent numberCA 1283445 C
Classification (IPC)G01R27/02 +1 more

Timeline

Timeline From CIPO dates

1989199119931995199719992001200320052007Application filedJuly 22, 1988Patent grantedApril 23, 1991Term endedApril 23, 2008

Sources & verification

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