Home Made Siren Timer

[almdoc]

Hi Guys,
Has anyone out there built a siren control/timer using time delay relays etc. I'm not to keen on the electronic stuff. I prefer heavy duty so thats why I like relays. An alert tone for one minute is no problem. A single delay relay will do that. What I need is an attack signal for approx. one minute. Any ideas ? Thanks.

[Daniel]

Check out any company selling Velleman kits. Velleman is a Belgian manufacturer of electronic kits and sells large numbers of them in the United States. They have an interval timer kit that costs about $15. You can adjust the on and off times of the relay. As long as power is applied, it cycles on and off at the intervals you set, and mine can go about 7 seconds maximum on-time. An advantage of 555-based timers is that the first cycle is a little longer, which like older siren timers, compensates for the windup to make the first cycle sound as long as the others. Velleman also has a simple 1 second-5 minute timer kit, so if you combined both kits together, you could create a one-minute attack signal for about $25, not including a low voltage power supply and a motor contactor.

If you would rather keep things electromechanical, search Ebay for cam timers. Many are made by Crane or Eagle, and are used for old traffic signals, freezer defrost timers, and HVAC units. Find one with motor speed of around 1 RPM or a little slower (1/3 RPM = 3 minute cycle). Cut notches into the cam for the desired signal, and make sure that the timer you buy has at least two wheels and two switches: one for the siren relay and the other to stop the clock motor at the end of the cycle.

[dilloncarpenter]

I believe djscrizzle on this board has a home-made timer of some sorts. Sorry, that's all the info i got.

[Adam Pollak]

Interesting timing that you just asked that, because I just got mine up and running. It runs my 220 volt Model 2T on 110 volts everyday at noon for 8 seconds. If everything work out, I'll redo the wiring after a bit (not use electrical cords, use conduit, use grounding) and make it more permanent, but it works well for now.

I also later wanted to see if I could find a nearby power source on a different phase from the outlet I am powering from now. This would allow me to pull 220 volts from 2 x 120 volt outlets. I'd set up my AR timer on the wall next to this and have another double-throw relay in there. If the noon timer activates it, it will go off with 110 volts, if the AR timer activates it, it will go off on 220 volts. I just need to see if the bedroom and bathroom power or outside lights power is on a different leg to get 220.

You can see a (too-windy) video here:
http://www.youtube.com/watch?v=YYWWaY1yP1I

[djscrizzle]

I've made 2 timers in the past; one's in a big NEMA 3-R box, and is toughened to be able to run larger siren's starters, and thus for the municipal market.

The second one, is in a plastic case, and was an experiment in miniaturization; and was geared for the casual home user.
Both are yellow, and are easily turned around in a week's time, since both use off-the-shelf components. Both timers have local siren tone generators in them.

http://airraidsirens.com/forums/viewtopic.php?t=4921