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:
Jul. 04, 1995
Filed:
Feb. 24, 1994
Chun-Foong Cheah, Foster City, CA (US);
Precision Navigation, Inc., Mt. View, CA (US);
Abstract
Measurement circuitry for a biaxial inclinometer having electrolytic fluid incorporates a Schmitt trigger for measuring the resistance of each leg of the inclinometer by measuring the frequency output of the Schmitt trigger circuit while each leg is placed across input and output terminals. Switching is accomplished by cycling analog multiplexers as solid-state switches under control of a microprocessor. To minimize net dc current across any leg, legs are periodically reversed in polarity as they are switched into the Schmitt trigger circuit for measurement. Additionally, in the wiring of the switching multiplexers to the inclinometer legs, an additional analog multiplexer is switched to place a low clamp resistance in parallel with each leg not being measured in a cycle, to compensate for leakage current.