Communications: electrical – Systems – Call station
Patent
1975-08-20
1977-05-17
Caldwell, John W.
Communications: electrical
Systems
Call station
315135, 340267R, G08B 2300
Patent
active
040245217
ABSTRACT:
An alarm indicator system which is utilized in combination with electrically energized apparatus, the alarm indicator including a plurality of individual indicator lamps for indicating an open-circuit condition in any one of a plurality of circuits. A master alarm lamp is provided which is energized upon the energization of any one of the individual or specific indicator lamps. The electrically energized apparatus includes, as is conventional, a plurality of drive means functioning from a source of electrical power,with relay means having normally open contacts being utilized upon closure to deliver power to the drive means of the apparatus. The master alarm lamp is arranged in parallel circuit arrangement with each of the indicator lamps, and a plurality of unidirectional conducting means such as diodes are interposed in series between the master alarm lamp and each of the normally closed contacts, with the unidirectional conducting means being uniformly poled with respect to the source of electrical power and with respect to each other so as to conduct in the same direction of current flow and effectively couple the master alarm lamp to each of the indicator lamps, while electrically isolating each of the indicator lamps, one from the other.
REFERENCES:
patent: 2112228 (1938-03-01), Crago
patent: 2839743 (1958-06-01), Baumgartner
patent: 2943303 (1960-06-01), Barber
patent: 3641490 (1972-02-01), Kawai
Caldwell John W.
Haugen Orrin M.
Myer Daniel
Sheldahl Inc.
LandOfFree
Alarm indicator circuit using indicator lamps 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 indicator circuit using indicator lamps, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Alarm indicator circuit using indicator lamps will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1837825