Fire alarm system comprising a plurality of alarms which may be operated by way of an alarm loop
First Claim
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1. A fire alarm system comprising:
- a plurality of alarm circuits which are connectible in analarm loop for interrogation; and
a central control connected to said alarm loop including means for applying operating power to said alarm circuits and means for receiving signals generated by said alarm circuits,each of said alarm circuits comprising;
a detector for detecting a predetermined characteristic of a fire and generating a representative first signal, signaling means connected to said detector and operated by said first signal to amplify and place the same as an amplified second signal on said loop,said signaling means including a timing circuit having a load resistance connected in parallel to said loop by said signaling means.
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Abstract
A fire alarm system comprises a plurality of alarms which may be operated via an alarm loop and which, being subject to selective interrogation, each alarm transmits an analog value of a particular characteristic of a fire to a central control, the analog value being tapped from a detector for that characteristic. Each alarm comprises an alarm circuit which has a load resistor which can be connected in parallel to the alarm loop by means of a timing element and which amplifies the current which characterizes the alarm at the instant of interrogation.
36 Citations
7 Claims
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1. A fire alarm system comprising:
- a plurality of alarm circuits which are connectible in an
alarm loop for interrogation; and a central control connected to said alarm loop including means for applying operating power to said alarm circuits and means for receiving signals generated by said alarm circuits, each of said alarm circuits comprising; a detector for detecting a predetermined characteristic of a fire and generating a representative first signal, signaling means connected to said detector and operated by said first signal to amplify and place the same as an amplified second signal on said loop, said signaling means including a timing circuit having a load resistance connected in parallel to said loop by said signaling means. - View Dependent Claims (2, 3, 4, 5, 6, 7)
- a plurality of alarm circuits which are connectible in an
Specification