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:
Nov. 23, 1993
Filed:
Feb. 18, 1992
Michel F Sultan, Troy, MI (US);
Charles R Harrington, Troy, MI (US);
John W Hile, Lake Orion, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
An apparatus comprises a sensor including a heater, an upstream detector and a downstream detector. An AC signal source excites the heater to generate propagating heat signals that are received by the upstream and downstream detectors. A first detecting circuit provides a first output signal responsive to the propagating heat signals received by the first detector and a second detecting circuit provides a second output signal responsive to the propagating heat signals received by the downstream detector. A difference circuit subtracts the first and second signals to obtain a difference signal and an output circuit provides an output signal responsive to the difference signal, which reflects both magnitude and phase. The resulting output signal has improved resolution and provides for improved sensor sensitivity.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile