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:
Feb. 20, 1979
Filed:
May. 23, 1977
Friedrich Rabus, Schwieberdingen, DE;
Hartmut Schweizer, Korntal-Muchingen, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
A method and apparatus for use with fuel mixture preparation systems which employ an oxygen sensor in the exhaust line to determine the composition of the combustible mixture supplied to the engine and which adjust the mixture on the basis of the bi-valued signals from the sensor. In order to permit the use of these signals at lower than normal operating temperatures, where the internal resistance of the sensor is high and the output signal is skewed, the invention proposes generating a correction current which is passed through the sensor and which causes a voltage drop which symmetrizes the output voltage so that the two branches of the output signal always lie respectively above and below a fixed set-point voltage, thus permitting control loop processing. A circuit is also described which supplies the correcting current by comparison of the DC level of the output signal with the set-point value in a secondary feedback loop.