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:
May. 22, 1990
Filed:
Nov. 03, 1988
Steven C Fossum, Hopkins, MN (US);
J Gregory Sedivy, Prior Lake, MN (US);
Wayne K Savick, Eden Prairie, MN (US);
Innovex Inc., Hopkins, MN (US);
Abstract
A self-zeroing differential pressure signal generator. A strain gauge separates two areas of potentially differing fluid pressure and generates an electrical signal which varies as the fluid pressure difference varies. The strain gauge electrical signal is applied to the noninverting input terminal of noninverting amplifier, which develops a zeroed output signal. The noninverting amplifier includes a feedback loop which sums a feedback signal from the noninverting amplifier output with a zeroing compensation signal at the inverting input terminal of the amplifier. The zeroing compensation signal is developed by periodically eliminating the zeroing compensation signal and simultaneously exposing the strain gauge to a zero pressure difference. The output signal of the noninverting amplifier is compared to a reference output and a zeroing compensation signal is generated which, when summed with the feedback signal, brings the value of the output terminal to the value of the reference output.