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:
Oct. 25, 1988
Filed:
May. 20, 1986
Robert Kugler, Wendelsteih, DE;
Hans-Eberhard Simmel, Karlsruhe, DE;
Siemens Aktiengesellschaft, Munich, DE;
Abstract
A method for generating a circuit-breaking signal in dependence upon the magnitude and duration of an excess current, where a measured quantity, derived from the excess current, is sampled, is converted into digital values, and these values are weighted in accordance with a predetermined function and are added in order to obtain a circuit-breaking signal when the sum exceeds a predetermined comparison value. In order to improve upon a method of this kind in such a manner that, in the case of a diminishing excess current, a false interruption of the circuit is safely prevented, an auxiliary quantity (.DELTA.i) is formed which corresponds to the difference quotient or differential quotient of the measured quantity (M) and when the absolute amount of the auxiliary quantity (.DELTA.i) is already below a predetermined limit value and the sampled value of the excess current is below a predetermined threshold (S), the addition is interrupted.