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:
Sep. 25, 1990
Filed:
Mar. 01, 1989
Masanobu Uchinami, Himeji, JP;
Toshihisa Takahashi, Himeji, JP;
Hitoshi Inoue, Amagasaki, JP;
Takahiro Moronaga, Himeji, JP;
Shinichi Nishida, Himeji, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
The air-fuel (A/F) ratio controller of an internal combustion engine related to the invention detects occurrence of abnormal condition in a heater on the basis of the resistance value of this heater which heats an oxygen sensor generating a specific voltage responsive to the difference of oxygen concentration between atmosphere and exhaust gas of the engine and of an oxygen pump allowing the pump current flow in order that the voltage can be the predetermined value. If abnormal condition arises in the heater, the A/F ratio controller stops fuel feedback control operation. The A/F ratio controller related to the invention forms a Wheatstone bridge circuit which includes the heater mentioned above and detects occurrence of an abnormal condition in the heater on the basis of the equilibrium condition of signal outputted from the Wheatstone bridge circuit.