How can I trigger an event from a 12VDC output?

I have a dumb house alarm I’d like to trigger some lights from. When the alarm detects an intrusion it will apply 12VDC to a cable that is coming out of the main alarm box. I’d like to use this 12VDC as an input to a device which will then trigger lights to come on or cameras to record for example. What’s the most appropriate device to take this 12VDC as an input to trigger an event?

You can get a dry contact transformer that’s rated for 12VDC and then use a Ecolink or Monoprice Door Contact that has a dry contact nodes.

The sensor will read open and close based on the transformer dry contact and then you use that to do whatever.

Thanks @rontalley, I’m not too up to speed on my electrical terminology. If you had any specific transformers in mind I’d appreciate a link and I could try get the same/similar model, thanks

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These two should be perfect.


Hmm, I’m based in Europe (Ireland actually). Finding it difficult to source an equivalent of the relay in online shops that deliver here :frowning: