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:
Jun. 11, 1985
Filed:
May. 03, 1982
Kenneth L Frick, Westminster, CO (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
A microcomputer controlled circuit arrangement for sensing fire and burglar alarms in the presence of undesired fault conditions, such as opens or shorts, on monitored communication lines. The arrangement includes transistor-resistor sensing circuitry which is shared by a plurality of monitored communication lines, each of which comprises a first pair of conductors connected to a first contact of an alarm sensor and a second pair of conductors connected to a second alarm sensor contact. The sensing circuitry is connected through a multiplexer to each one of the lines one at a time under control of the microcomputer to detect any fault thereon and any alarm provided by the sensor contacts. The sensing circuitry is responsive to impedance conditions on the four conductors furnishing a plurality of output voltages which are examined by comparators that, in turn, generate combinational logic voltages signifying the alarm-fault state of a monitored line.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile