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:
May. 05, 2015
Filed:
Nov. 29, 2012
Tyco Safety Products Canada Ltd., Concord, CA;
Andrei Bucsa, Toronto, CA;
Stephen D. W. Fosty, Brampton, CA;
Tyco Safety Products Canada Ltd., Concord, Ontario, CA;
Abstract
A bi-directional current limiter may be configured to receive an AC signal and bi-directionally limit the loop current to a predetermined current value. A first and second zone may be configured in series with the AC signal and bi-directional current limiter. The first and second zone may include unidirectional current limiters to limit a unidirectional current that is proportionately less than the bi-directionally limited current. A first opto-coupler circuit (ISO) may be configured to detect both high and low current states in the current loop circuit. Second and third opto-coupler circuits (ISOand ISO) associated with the first and second zones may be configured to detect only high current states in the current loop circuit. The status of the first and second zones may then be determined by an analysis of the current level in the current loop circuit during two half cycles as determined by the various current limiters.