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:
Jan. 17, 1989
Filed:
Aug. 11, 1987
Hitachi, Ltd., Tokyo, JP;
Hitachi Automotive Engineering Co., Ltd., Katsuta, JP;
Abstract
A detecting element (6) comprising a solid zirconia electrolyte (6a), a reference electrode (6d), a detecting electrode (6c) and a diffusion member (6a) is provided, and also a driving circuit (1b, 4) for impressing a voltage between the electrodes (6c, 6d) of said detecting element so as to detect the threshold current of an oxygen ion pumping current (I.sub.p) is provided. The output of this driving circuit is delivered as a continuous output (V.sub.o) of an air fuel ratio of fuel gas comprising al the regions of rich, stoichiometric and lean air fuel ratios. On the other hand, an I.sub.p detection resistor (Rs) for detecting the pumping current flowing between the input/output terminals of the driving circuit is provided. The opposite-end voltages (V.sub.a, V.sub.o) of this I.sub.p detection resistor are compared by a comparator (5), and a step signal corresponding to the stiochiometric air fuel ratio (.lambda.) is outputted from this comparator.