Smoke Alarm

Don't muck around with an existing smoke alarm and compromise its safety, you are asking for trouble. Use one of the 12V wired smoke alarms designed to attach to a home alarm system. You could even use a low cost one or two zone alarm system to monitor it, then you get proper battery backup protection etc. You can even get wireless smoke detectors, once again designed for home alarm systems.

Dave :)

"thesnowbaron"

** If the beeper has more than two wires ( my example of a First Alert alarm has three ) make SURE you have it wired in the correct order to the PCB.

....... Phil

Buy the item suitable for the job.

System Sensor 2012H

Operates off 12 volts and has an normally open set of relay contacts which would be suitable for connection of a secondary sounder.

a> it sounds like the capacitance of the phone cable is too high - you could try using cable with a lower capacitance. eg: tv-antenna ribbon. b > Reassemble the alarm and use a baby monitor with the squelch turned up.

c > replace the sounder on the alarm with a diode pump. run the DC from this through the phone cable at the other end use the DC to trigger an alarm.

maybe something like this: .---- +V | [SIREN] 10nF | || / --> >--||--. |/ || | .----------| | | |\| .->|-+-->|---->...>---+-[100K]-. ~\ | | | ---> >-+------------->...>------------+----+---- 0V Bye. Jasen

On Tue, 4 Jul 2006 11:16:55 +1000, "thesnowbaron" put finger to keyboard and composed:

Depending on the design, you may be able to wire an optocoupler across the existing beeper. Then use the output of the optocoupler to control a second, remote, battery powered beeper. Alternatively, if an LED illuminates when the siren goes off, then you could wire the optocoupler in series with the LED.

- Franc Zabkar

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Jaycar have a 12V hardwired smoke detector on sale that has NO and NC relay contacts for remote alarms, or other devices. LA-5045 $24.95 each.