Controlling Fans

[plutoniumJoe]

I was looking for a way to control fans on my hood. The metal halide bulbs and ballast run on a simple 120v timer, however I am using an old pc power supply to run all my DC things like L.E.D.s and fans. I can't put my pc power supply on a timer because at some time during the day something is running off of it. I was wondering if anyone knows of a way to make my 12v or 5v fans kick in when the lights go on or for my moon lights to go on when my big lights go off. I am thinking there must be some type of relay that I could use or even a thermostat controlled relay for the fans.