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. 07, 1986
Filed:
Oct. 23, 1985
Hans-Eberhard Simmel, Karlsruhe, DE;
Siemens Aktiengesellschaft, Munich, DE;
Abstract
A digital overcurrent tripping arrangement having a nonpermanent digital memory. The arrangement further contains a resistor-capacitor stage that simulates the cooling-down process of a body. In accordance with the invention, a microprocessor uses a thermal excitation state digital value stored in the nonpermanent memory to calculate a digital normalized voltage value which is then stored in the nonpermanent digital memory. A digital comparator means within the microprocessor compares the digital normalized voltage value in the nonpermanent memory with a digital output of an analog-to-digital converter, the digital output corresponding to a voltage across the resistor-capacitor stage. If they agree, a charging switch between a current supply and the resistor-capacitor stage is opened. Upon reconnection of the main current supply after disconnection, the microprocessor stores the digital output of the analog-to-digital converter in the nonpermanent memory, the digital output corresponding to a residual voltage across the resistor-capacitor stage.