I'd be curious to see the schematic for this too, both a 120V and 220V version (one for the shop-vac, one for a future dust collector). I haven't done any research yet, and I have no real electronics experience, so please dumb it down. :) Fairly specific details and a pretty picture would be ideal! For my part, I'll commit to putting together the documentation and putting it up on a website, if it's not already on one.
My very quick and dirty research gave some information on hooking up the relay, which is what I think I need to do. But the actual details are still pretty fuzzy. My understanding is that I'd have a 12V (steal a transformer from some dead electronic device, or buy a Radio Shack one?) loop that would go to the different blast gates. Opening one of those gates would complete that circuit. This current would cause the relay to close, which would turn on the power to whatever device was connected to it. Is it that simple?
Another scenario (the "really" ideal one) would be this. I turn on the power to my saw. Doing so magically opens the blast gate for that device (solenoid?) and turns on the dust collector/shop vac (relay). But how do you detect the power flowing to the saw? I know that Sears has their handy-dandy power bar for that, but to be perfectly honest, I'd rather keep the saw and filtration device on separate circuits, as I'm not a big fan of blowing circuit breakers. Also, I'd like to hook this up to my table saw, router, miter saw, bandsaw, and drill press. The tablesaw is 220, the rest are 110, and scattered around the gara-shop.
Again, I am willing to document this and publish on the web so you only have to help once! :) Thanks for any input.
Clint