IMPROVED 2 wire fire alarm circuit

361

03:38:55

Newer fire alarm devices operate over 2 conductors rather than having separate power wires ran to each device. This configuration delivers power so that devices like smoke detectors can function, while detecting alarm condition over the same pair of conductors. In my circuit the devices are not supervised and alarms are not latching because that is not the purpose of this demo.
*added 10 ohm resistor to account for wire length and 1 ohm resistor to account for contact resistance* 
-Credit : Hurz

published 7 years ago

hurz

7 years ago

Needs some rework. What resistance do you expect for a 10m two wire cable? Your switch must go below 1mOhm to trigger alarm! The cable will have alread more resistance, so no alarm can be triggered! Anyway, i think fail safe systems would do it the other way around and do detect an open and noz an close. BTW, how many detectors do you plan to put at two wires?

Sgd0072

7 years ago

Thanks for the input. All detectors are most certainly normally open though.

hurz

7 years ago

check this http://everycircuit.com/circuit/5985859942481920

Sgd0072

7 years ago

Okay thank you!

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