Method and assembly for operating an electrical heater of a catalytic converter system

US5694770A · kind A · utility

Assignee

• EMITEC Gesellschaft fuer Emissionstechnologie mbH · DE

Inventors

• Rolf Brück · Bensberg, DE
• Helmut Swars · Bensberg, DE

Key dates

• Filing date: Aug 9, 1994
• Grant date: Dec 9, 1997
• Expiry date: Aug 9, 2014

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/40
• WIPO field: Environmental technology
• WIPO sector: Chemistry

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.