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. 03, 1980
Filed:
Nov. 05, 1975
Dennis L Kurschner, Minnetonka, MN (US);
Honeywell Inc., Minneapolis, MN (US);
Abstract
A system for detecting intrusions into a protected area by personnel, vehicles, or other objects, including a sensor capable of detecting magnetic and/or pressure disturbances and a signal processing means for generating an alarm signal when an unwanted intrusion occurs. The signal processing apparatus includes a first band-pass filter for selecting the portion of the signal from the sensor which is within a first frequency range, and a second band-pass filter for selecting a portion of the signal within a second frequency range. Logic circuitry is provided to process the two analog signals from the two band-pass filters using amplitude, signal energy and zero-crossing characteristics of the two signals in a cross-channel relationship to eliminate false alarms which might be caused by disturbances such as lightning, thunder, or wind.