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:
Mar. 19, 1996
Filed:
Dec. 19, 1994
Douglas R Hamburg, Bloomfield, MI (US);
Eleftherios M Logothetis, Birmingham, MI (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
An engine air/fuel control system is shown (300-428) responsive to a feedback variable derived (410-428) from an exhaust gas oxygen sensor (16) positioned upstream of a catalytic converter (20). A non-catalytic exhaust gas oxygen sensor (24) having a non-catalytic electrode (490) positioned in the engine exhaust downstream of the converter (20) is coupled to a current pumping circuit (28). Current is pumped into an electrode of the downstream sensor (24) shifting its output step change towards richer air/fuel ratios. Pumping current is gradually increased in amplitude until the downstream sensor (24) incurs a change in its output state (602-634). The pumping current occurring at the time of such change in output states provides a measurement of catalyst efficiency.