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:
Nov. 11, 1986
Filed:
Jan. 09, 1984
Roy Stockdale, Halesite, NY (US);
Napco Security Systems, Inc., Copiague, NY (US);
Abstract
There is disclosed an intrusion detection system employing vibration sensors which are arranged in a series loop consisting of first and second wires and which loop is terminated by a terminating impedance. Coupled to the wires is a processing circuit which supplies a square wave biasing waveform for the loop and a DC voltage determined by the terminating impedance. By detecting the magnitude of the DC level, the processor can determine if the loop has been opened or shorted or if any one of the sensors in the loop has been activated due to an intrusion. Thus the system described employs two wires for supplying both power and sensing of output signals from the loop being monitored.