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:
Jul. 21, 1981
Filed:
Aug. 02, 1979
Wolf Wessel, Oberriexingen, DE;
Dieter Handtmann, Sindelfinger, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
A method for measuring the air quantity supplied to an internal combustion engine by means of a measurement sensor disposed in a bridge circuit having a temperature-dependent resistor (for example, a hot wire or hot film) in the air intake manifold and having a temperature control apparatus, the temperature of the measurement sensor being controlled in an open or closed loop independently of the temperature of the medium to be measured, the properties of the medium to be measured which cause the measurement effect in the hot wire or hot film being dependent on the temperature. With an identical flow quantity but different temperatures in the medium, a correct measurement indication is obtained by making the excess temperature of the hot wire dependent on the temperature of the medium to be measured. The apparatus for open-loop or closed-loop control of this excess temperature contains, in the parallel arm to the quantity measurement device of the bridge circuit, two resistors disposed in sequence, one of which is also disposed in the air intake manifold in order to detect the air temperature, and the total temperature coefficient is set, by means of the selection of the individual temperature coefficients of the two resistors as well as their resistance values, in such a manner that the actual measurement sensor has a controlled excess temperature.