The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Dec. 31, 2002

Filed:

Sep. 29, 2000
Applicant:
Inventors:

Ernst H Dummermuth, Chesterland, OH (US);

Patrick C Herbert, Mentor, OH (US);

Steven M. Galecki, Painesville, OH (US);

Assignee:

Rockwell Automation Technologies, Inc., Mayfield Heights, OH (US);

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01R 2/726 ;
U.S. Cl.
CPC ...
G01R 2/726 ;
Abstract

A capacitance comparison circuit determines the relative value of two capacitors, such as may be sensor elements, by monitoring voltage changes caused by charge redistribution between the capacitors when they are series connected and then connected alternately in a first and second polarity across a voltage. The direction of change of voltage at the junction of the capacitors with respect to the switching of polarity of their connection precisely reveals which capacitor is larger. Disconnecting the voltage monitor during the switching reduces switching induced errors.


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