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. 01, 1982
Filed:
Apr. 28, 1980
Samuel Raber, Allendale, NJ (US);
Irving L Ellner, Hopatcong, NJ (US);
Baker Industries, Inc., Parsippany, NJ (US);
Abstract
An intrusion detection system includes a vibration sensor, and a gate circuit operable to provide an output signal only after the vibration sensor produces a first signal, and thereafter a second, separate signal within a preassigned 'sensing window' period. To accomplish this, a timer circuit initiated by the sensor determines a timing interval, and a delay circuit coupled to the timing circuit prevents switching of the gate circuit until preset delay time has elapsed. After the delayed time, if a second sensor output signal is received before expiration of the timing interval, the gate circuit switches and passes a signal through an integrated circuit amplifier stage, and a driver circuit to energize an output unit. The sensitivity of the vibration sensor can be adjusted. The integrated circuit stage includes circuitry for maintaining the alarm signal even if the system is switched to off after it goes into alarm. The same stage also checks periodically for a low battery condition, and provides an output warning signal if the battery level falls below a preset level.