Communications: electrical – Condition responsive indicating system – Specific condition
Patent
1977-01-24
1978-07-18
Swann, III, Glen R.
Communications: electrical
Condition responsive indicating system
Specific condition
340568, G08B 1318
Patent
active
041018761
ABSTRACT:
A security system is provided in which the monitoring of an article to detect an alarm condition involves sensing the effect of the article on ambient electromagnetic radiation, such as light, and initiating an alarm when the effect of the article on the radiation indicates an alarm condition. According to one aspect of the invention, the effect of the article on ambient radiation is sensed by comparing direct measurements of the radiation with measurements of the radiation along a path normally intercepted by the article. In one form, the security arrangement of the invention includes two light sensing devices, one of which is arranged behind the article to be protected, or is otherwise concealed by such article, and the other of which is arranged to sense ambient radiation. These lead directly into a group of comparators, the output of which is sensed for rate of change in order to control the sounding of a local alarm or a full-security alarm. The alarms may also be tripped directly by respective ones of the comparators or by devices for sensing tampering with the arrangement.
REFERENCES:
patent: 3309689 (1967-03-01), Keeney
patent: 3432842 (1969-03-01), Poznanski
patent: 3544988 (1970-12-01), Astheimer
patent: 3719938 (1973-03-01), Perlman
patent: 3745550 (1973-07-01), Anthony et al.
patent: 3930249 (1975-12-01), Steck et al.
Hill John I.
Lurkis Alexander
Glimmer Security Systems Inc.
Swann III Glen R.
LandOfFree
Photo electric security system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Photo electric security system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Photo electric security system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-342027