Buying Optocouplers

[bimm25e]

So I need to close a 24VDC circuit when a Jamma button is pressed, I think an optocoupler is going to be my best friend here But I don't know how to shop for them, I want to make sure I buy one that will be able to trigger on 1V and support a 24V circuit on the other side

[nitrogen_widget]

I would look at circuits used to trigger SSR's by the Raspberry PI & Arduino communities.
You will need a transistor & a 2nd power source to trigger most solid state relays because 1v probably won't be enough.

here is an example.

http://forums.adafruit.com/viewtopic.php?f=8&t=48936