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:
Apr. 03, 1984
Filed:
Dec. 02, 1982
Nissan Motor Company, Ltd., Yokohama, JP;
Abstract
An air/fuel ratio detection system for an IC engine, using an oxygen sensor element of the concentration cell type which has a laminate of a measurement electrode layer exposed to the exhaust gas, a porous layer of oxygen ion conductive solid electrolyte and a reference electrode layer and requires the supply of a small DC current thereto to produce a reference oxygen partial pressure at the reference electrode by a balance between migration of oxygen ions to the reference electrode and diffusion of oxygen molecules therefrom. To prevent excessive rise in the reference oxygen partial pressure even when the engine continues to discharge exhaust gas high in the content of oxygen, the detection system has a control circuit which controls the intensity and flow direction of the current for the sensor element with reference to a voltage which is produced by adding a definite voltage to, or subtracting the definite voltage from, the sensor output voltage depending on the level of oxygen content in the exhaust gas indicated by the sensor output voltage and smoothing the voltage resulting from the addition or subtraction.