On 14 Dec 2005 14:53:05 -0800, "autonut843"
wrote:

Once again, I should have Googled first and I would have found my
answer. The Firex manual for one of their interconnected smoke
detectors says...


This smoke alarm should be installed in accordance with the NFPA's Standard 72 (National Fire Protection Association,
Batterymarch Park, Quincy, MA 02269) and any local codes that apply.

When interconnecting, use #18 AWG minimum solid or stranded wire. Maximum wire length between any two is 1,500
feet for #18 AWG or 4,000 feet for #14 AWG (20 OHMS loop resistance).

DO NOT connect to any other type or model of heat or smoke alarm. Connect smoke or heat alarms to a single AC
branch circuit. If local codes do not permit, be sure the neutral wire is common to both phases.


So, I think that explains why I haven't found a commercially available
relay module to do what I was looking for.

Does anybody have a good idea for a passive way to monitor if the smoke
detector is going off? I guess I'm thinking something like a sound
pressure level sensor or something like that. Obviously it wouldn't be
foolproof. Any other ideas?

The only other idea I have is what you said you didn't want to do, but
after some hesistation, I did it.

I have, the house came with 110 volt smoke detector in the hall
outside my bedroom. In parallel with the noisemaker thing inside the
detector, I put a relay that connects to my burglar alarm which sounds
a constant noise, not the pulsating noise that breaking into the house
causes. I used a fairly large relay but it was still small enough to
stuff into the original hole in the ceiling.

It says on the smoke detector not to fiddle with it, of course, but my
relay uses less than the noisemaker, and the it's all 110 volts so
it's not going to overdraw from a battery. I've tested it more than
once. Although it is so loud that I only do it in the middle of a
weekday when my neighbors mostly aren't home.

When I sell the house, I'll give them notes about everything I've done
to it.



Remove NOPSAM to email me. Please let
me know if you have posted also.