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.
Patent No.:
Date of Patent:
Sep. 25, 2001
Filed:
Nov. 10, 2000
Keith S. Champlin, Minneapolis, MN (US);
Other;
Abstract
A device measures complex self-immittance of a general element at a discrete frequency by implementing “sine/cosine correlation” in software. An active source excites the element with a periodic voltage or current having fundamental period equal to the reciprocal of the desired measurement frequency. Linear circuitry senses two signals; one proportional to the periodic voltage or current excitation, the other proportional to the periodic current or voltage response. Identical low-pass or band-pass filter-response functions process each signal to remove higher-order harmonics. The resulting band-limited signals are each sampled in synchronism with the excitation, digitized, and inputted to a microprocessor or microcontroller which performs the appropriate calculations.