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:
Dec. 09, 1997
Filed:
Aug. 09, 1994
Rolf Bruck, Overath, DE;
Helmut Swars, Bergisch Gladbach, DE;
Emitec Gesellschaft fuer Emissionstechnologie mbH, Lohmar, DE;
Abstract
An assembly for operating an electrical heater in a catalytic converter system connected in an exhaust gas cleaning system downstream of an internal combustion engine. The electrical heater is supplied with an electrical heating current through an electronically controlled power switch. The system is heated with the electrical heater to or above a minimum temperature necessary for catalytic conversion. The temperature of the catalytic converter is measured and utilized as a controlled variable of at least two different control circuits. At least one preferred control circuit is defined from a plurality of control circuits. The system is controlled in regular operation with the preferred control circuit. The preferred control circuit is automatically monitored for malfunction and, if a malfunction is detected, control is automatically transferred to another control circuit.