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. 13, 1999
Filed:
Jan. 21, 1998
Applicant:
Inventors:
Assignee:
K. A. Schmersal GmbH & Co., KG, Wuppertal, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G08B / ;
U.S. Cl.
CPC ...
340635 ; 340644 ;
Abstract
The state of operability of a circuit having at least one group of condition responsive monitoring switches, the switches having first terminals connected to an input signal source and output terminals connected to an evaluation unit, is monitored by periodically interrupting the connection between at least one of the condition responsive switches of each group and the evaluation unit. The evaluation unit compares the change in potential at the output terminal of the one switch, resulting from the interruption, with the potential at the output terminal of another switch.