Communications: electrical – Condition responsive indicating system – With particular coupling link
Patent
1978-11-08
1980-11-18
Robinson, Thomas A.
Communications: electrical
Condition responsive indicating system
With particular coupling link
455 27, G08B 108
Patent
active
042348749
ABSTRACT:
A burglar or fire alarm is presented which cannot be disabled by cutting the power or telephone lines and which virtually cannot be radio jammed. A radio transmitter comprises an automatic switch which repetitiously and cyclically switches the carrier frequency of the transmitter between a plurality of frequencies in seriatim for transmission of an alarm signal to a distant receiver so that if at least one of the frequencies is rendered unusable by burglars by jamming or the like, the other of said frequencies will still be usable. A tape player provided with a pre-recorded message signalling an alarm condition is connected to modulate the carrier frequencies. A speed adjustment means is provided for the tape player for changing the playing time for said message. The speed adjustment permits the tape player to play back the message for transmission at a plurality of rates including an increased rate too fast for human comprehension for communication with a computer.
REFERENCES:
patent: 2522615 (1950-09-01), Hughes
patent: 3044015 (1962-07-01), Overkamp, Jr. et al.
patent: 3909722 (1975-09-01), Bennett, Jr.
patent: 4109239 (1978-08-01), Davis
Brown Laurence R.
Inventional/Security Development Corp.
Robinson Thomas A.
LandOfFree
Alarm system and method thereof does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Alarm system and method thereof, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Alarm system and method thereof will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-600415