Communications: electrical – Systems – Call station
Patent
1976-06-03
1977-03-08
Swann, III, Glen R.
Communications: electrical
Systems
Call station
340214, 340258B, 340283, G08B 1326
Patent
active
040115542
ABSTRACT:
This intrusion alarm apparatus is intended to be suspended from an inside doorknob and plugged into an A.C. power socket at the premises to be protected. A test switch and indicator lamp enable the user to determine (without triggering an alarm) whether the plug has the correct polarity in the power socket. The alarm signalling device in the apparatus or the indicator lamp is activated by the added capacitance of a person or an extraneous metal object touching the outside doorknob, depending upon whether the switch is in the "test" or "on" position.
REFERENCES:
patent: 3313960 (1967-04-01), Boris
patent: 3465325 (1969-09-01), Goldfarb et al.
patent: 3623063 (1971-11-01), Fontaine
patent: 3648076 (1972-03-01), Lester
Butler & Law Incorporated
Swann III Glen R.
LandOfFree
Intrusion alarm apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Intrusion alarm apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Intrusion alarm apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1409499