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:
Dec. 16, 1986
Filed:
Feb. 19, 1985
Yoshishige Oyama, Katsuta, JP;
Minoru Osuga, Katsuta, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An air-fuel ratio detector including an oxygen ion conductive solid electrolyte, first and second electrodes provided on respective sides of the solid electrolyte, a porous diffusion resistor covering the first electrode, and a circuit arrangement for supplying a current between the first and second electrodes. In order to enable a detection of a wide range of air-fuel ratios, the current supplied between the first and second electrodes is controlled so as to feed oxygen from the second electrode to the first electrode through the solid electrolyte and then withdraw oxygen from the first electrode to the second electrode through the solid electrolyte. At the time of withdrawal of the oxygen, the mobility or migration of the oxygen is measured, with the mobility of the oxygen being detected in dependence upon a variation rate of a withdrawal current, an average value of the withdrawal current, or a time period from the starting time of the withdrawal to a time when the oxygen content near the first electrode has become nearly zero.