question re: latching via a voltage drop

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

Robert Scibienski - 28 Sep 2007 04:25 GMT

I have a series of120V latching smoke detectors installed in my home
for which the latching signal appears to be a drop from 120 to 110
volts in the latch line. At least that is the only signal I can detect
when one of the detectors is activated. I would like to be able to
transfer an alarm signal to a central burglar alarm which I recently
installed. This requires the simple closing of a circuit. Can anyone
suggest a device which will detect this small voltage drop off and
output a relay activation signal?
Thanks in advance -
Bob S.

Reply to this Message

ehsjr - 28 Sep 2007 19:01 GMT

> I have a series of120V latching smoke detectors installed in my home
> for which the latching signal appears to be a drop from 120 to 110
[quoted text clipped - 6 lines]
> Thanks in advance -
> Bob S.

Connecting directly to the smoke detector circuit is probably
not a good idea in the absence of schematics/knowledge of the
system. You might interfere with proper smoke detector operation.
Why not use an audio interface? Pick up the sound of the alarm
and use that to trigger the relay.

Ed

Reply to this Message

Electronics Forum / Basics / September 2007

question re: latching via a voltage drop