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:
Apr. 01, 1997
Filed:
Mar. 25, 1996
Ludwig Schifferl, Pentling, DE;
Andreas Wildgen, Nittendorf, DE;
Siemens Aktiengesellschaft, Munich, DE;
Abstract
A temperature detector resistor and a sensor resistor are disposed in an intake manifold of an internal combustion engine. The two resistors each belong to a respective bridge branch of a measuring bridge having a bridge diagonal which is led to a first differential amplifier. A current in the bridge is adjusted in such a way that the sensor resistor always has a prescribed overtemperature. Due to backfires in the intake manifold, damage can occur to the sensor resistor due to sudden strong heating of the temperature detector resistor as a consequence of a strong rise in current. In order to avoid such damage, a third bridge branch is connected in parallel with the two bridge branches. The third bridge branch has a tap which is supplied, as is another tap, to inputs of a second differential amplifier having an output signal influencing the bridge current in such a way that the current is limited to a prescribed value. The device is applicable in internal combustion engines.