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:
Sep. 24, 2002
Filed:
Nov. 05, 2001
Michael Frey, Erfurt, DE;
Stefan Haimerl, Regensburg, DE;
Dieter Sass, Regensburg, DE;
Mario Seifert, Lengenfeld, DE;
Siemens Aktiengesellschaft, Munich, DE;
Abstract
A method and a device for an open-load diagnosis of a switching stage includes the steps of turning off the switching transistor if, after a first delay time has elapsed since an appearance of a control signal, the output voltage is less than a first reference voltage, and if, after a second delay time has elapsed, the output voltage is less than a second reference voltage, then, with the switching transistor in the on state again, comparing the output current flowing through the switching transistor with a reference current, and if the output current is less than the reference current, effecting an open-load indication. The device includes a switchable buffer amplifier; a switching transistor, second and third transistors, a reference current source, first and second comparators, and a control circuit connected to the buffer amplifier, to the second and third transistors, and to the first and second comparators.