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:
Jun. 13, 1989
Filed:
Feb. 01, 1988
Applicant:
Inventors:
Tetsusyo Yamada, Aichi, JP;
Sadao Ichikawa, Aichi, JP;
Assignees:
NGK Spark Plug Co., Ltd., Aichi, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01N / ;
U.S. Cl.
CPC ...
204425 ; 204426 ; 204427 ;
Abstract
An A/F detector having an output which is unambiguous over the entire operating region of the device, including both fuel-rich and fuel-lean regions. The detector includes two cells, an electrochemical cell and a pump cell. A constant current is passed through the electrochemical cell and the current through the pump cell is controlled in such a manner that the voltage across the electrochemical cell is constant. The current through the pump cell is detected to provide the unambiguous output signal.