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. 13, 1982
Filed:
Oct. 23, 1980
Tadashi Hattori, Okazaki, JP;
Yoshiki Ueno, Aichul, JP;
Nippon Soken, Inc., Nishio, JP;
Abstract
An air-fuel ratio detecting system detects the air-fuel ratio of the mixture supplied to an engine by means of titania whose electric resistance value varies in response to the oxygen content of the exhaust gases. The titania is connected in series with a reference resistor and a fixed voltage is applied to the junction of the titania and the reference resistor so as to generate a voltage corresponding to a change in the electric resistance of the titania. The detection voltage generated at the junction indicates the air-fuel ratio of the mixture and it is compared with a reference voltage for determining whether the air-fuel ratio is equal to the stoichiometric air-fuel ratio. The electric resistance of the titania varies with its operating temperature and the detection voltage varies correspondingly. To prevent any error in the control of air-fuel ratio due to a change in the temperature-dependent detection voltage, the peak value of the detection voltage which indicates that the air-fuel ratio of the mixture is greater than the stoichiometric ratio is sampled and the reference voltage is changed in response to the peak voltage. A programmable read-only memory is used to allow easy setting of the peak voltage and the reference voltage in a nonlinear relation with each other.