question re: latching via a voltage drop

[Robert Scibienski]

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.

 

[ehsjr]

Robert Scibienski wrote:

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.

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