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:
Nov. 15, 1977
Filed:
Sep. 18, 1975
Peter Schmidt, Schwieberdingen, DT;
Helmut Worz, Schwieberdingen, DT;
Robert Bosch GmbH, Stuttgart, DT;
Abstract
A fuel injection system for an internal combustion engine includes an electronic fuel controller which accepts signals representative of the air flow rate through the engine's induction tube as well as data relating to rpm and other parameters. The air flow rate data is derived from an electrically heated wire, located in the induction tube, which is connected in one branch of a bridge circuit. Changes in the air flow rate result in changes of heat transfer and hence of the temperature of the heated wire whose impedence changes accordingly. A control loop senses the imbalance of the currents in the two branches and acts to restore equilibrium, e.g. by increasing the total bridge current until a higher heat loss from the wire has been compensated. The increased bridge current is provided by periodic current pulses delivered by transistors under the control of a multivibrator. The multivibrator is triggered at a frequency which is a function of the imbalance signal voltage.