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:
Jun. 25, 1991
Filed:
Mar. 01, 1990
Ernst Kaller, Tamm, DE;
Karl-Heinz Kugler, Vaihingen, DE;
Christian Zimmermann, Ingersheim, DE;
Hans Koehnle, Schwieberdingen, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
In order to protect catalytic converters from damage caused by continued engine operation with a malfunctioning ignition system, a monitoring circuit checks current in the ignition coil primary winding. Primary winding current (i) is transformed by a measuring circuit (11) into a test primary voltage (U.sub.pr) which is fed to an evaluation circuit for comparison with ignition system supply voltage (U.sub.v) from the battery. During each primary current pulse, an instantaneous value is sampled, preferably during the earlier half of the pulse, and when the instantaneous test voltage (U.sub.pr) exceeds the supply voltage (U.sub.v) by more than a predetermined amount, the evaluation circuit (10) generates an error or malfunction indication. The ignition system can then be serviced before the catalytic converter is ruined.