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. 02, 1992
Filed:
Aug. 21, 1990
Jens Groger, Hanover, DE;
Karl-Heinz Hesse, Gehrden, DE;
Wolfgang Gudat, Seelze, DE;
Gerhard Ruhnau, Neustadt, DE;
WABCO Westinghouse Fahrzeugbremsen GmbH, Hanover, DE;
Abstract
A circuit for the surveillance of the switching state of a power transistor is constructed such that both, the voltage applied to the power transistor (1) is surveyed by way of a voltage comparator (7), as well as the voltage applied to the load (3) is surveyed by way of a further voltage comparator (8). The comparator (7) in the switched-on state and the comparator (8) in the switched-off state are activated by the input signal (U.sub.IN) of the power transistor (1). The output signals of the two comparators (7, 8) are combined to a status signal (U.sub.Stat). It is possible by way of the proposed circuit to recognize both a short circuit or, respectively, a shunt circuit of the load as well as a leakage current of the power transistor (1) and thus an interruption of the load occurs.