How to integrate a 12v horn siren?

I’m still a noob to all this, and I don’t want to put up my idea to avoid derailing anyone that actually knows what they’re talking about. So I’m going to ask. Let’s say I wanted to integrate a 12v siren, or 12v flashing light with ST. What equipment would I use to most cost-effectively create the bridge? Z-wave sirens, at least the ones I’ve seen, are just about worthless. I need some more oomph. Thanks in advance!

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Mimolite. :sunglasses:


What if I bought a Z-wave outlet or switch, and plugged/wired in an old 12v transformer? Could that rig be associated as a siren? Because I can get that one done for around $20.

I built my own custom siren + strobe light (both 12V). The siren I used is 119db, it’s plenty loud! See below for instructions on how I put it together

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Do you still have the link to where you purch power supply?

You can use any 12v laptop power supply off ebay. All you need to do is check the amperage. My siren uses 1 amp, so it’s pretty easy. I could actually use a regular 2 amp power supply from a small device. I’m using the old laptop power supply, which is overkill, because I already had it. Check the junk boxes before you place any orders!

Disclaimer: I’m not an electrician. I just play one on TV.

That’s where I’m going with it. I can get one of those Linear “GoControl” power switches for about $20, and then put it in a 2 gang box switching a standard outlet. Then plug the power supply into the outlet, and wire the other end to the siren. The siren I have is LOUD, so it’s for outdoors. I’ll do the same for something indoors, but with a smaller horn. Although I’m thinking of just using the standard z-wave sirens for that. I don’t need it TOO loud indoors.

This right here is the exact power supply I’m using.

But again, I didn’t buy it for this purpose.

I imagine most people reading this thread know this, but just a note that many jurisdictions in both the US and UK have legal limits on how loud sirens can be without a special permit. That might be a particular issue for anything controlled by SmartThings.

Remember that if you happen to choose a solution (some pocket sockets will be one) that does run locally and you activate it with SHM, if the smart things cloud is unavailable, the siren could still get activated and you would have no way of turning it off Except by physically accessing the siren or if you had planned in advance and had a minimote associated through The official smart lighting feature or direct association . If the cloud is not available, you can’t do anything in the smart things mobile app, including changing SHM status.

All of which is to say if it is legal where you live, make sure you plan for a way to be able to turn it off. :wink:


Way ahead of ya JD. The switch is going to be located in an accessible location, with Romex run to the outlet that will power the siren. So there will be a switch in the basement (breaker), and the Linear switch on the 2nd floor.

In my case, the outdoor siren isn’t for an alarm. It’s for a panic button. So theoretically it shouldn’t accidentally trip.

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