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. 12, 1994
Filed:
Aug. 26, 1992
Robert Bosch GmbH, Stuttgart, US;
Abstract
The invention relates to a method and an arrangement for monitoring the operability of a heater of an oxygen-measuring probe which is mounted in the exhaust-gas channel of an internal combustion engine. The principle of operation of the invention is based on the fact that the supply voltage of the probe heater drops during loading by the electrical resistance of the heating element. The voltage difference is dependent upon the magnitude of the resistance and therefore at least the three states can be distinguished, namely: normal operation, circuit interruption and short circuit. The operational state of the probe heater which is so determined is displayed to the driver by activation of a corresponding control unit and/or is stored, as required, in a fault memory. The arrangement according to the invention can be realized by a computer or in a compact configuration and is suitable for use in a central control apparatus.