temp monitor for lights

[powerboy]

to make something is rather easy. just a duplex plug and a thermostat.

power will be applied to plug after a cetain temp or below, depending on how you wire it.

now as far as practicality, thats another issue. unless you go out and buy a sophisticated temp controller that has a temperature differential, what happens when the temp hovers just over the set point? you will have cycling of the halide. and as you know, halides take some time to fire up after being turned off, and what if the time it takes is not the same time as it takes the temp to go down? then its redundant. (hope i explained that correctly)

im sure you could do it and it not cost "hundreds of dollars"
you will have to due your research. to point you in the right direction, look at the different RANCO controllers. they make a number of them and im sure one will suit your application. but be forwarned, its not going to be a 20 or 30 dollar thing.

the trick is to have say a 10 degree difference between the coldest and warmest setting.

its a tricky thing, because what you are trying to do is adapt something designed for a fan (temperature) to work with lighting.

good luck, hope i helped