I'm wiring up my shop. I have a total of 8 separate wall circuits. One circuit is solely for the dust collector. Two of them are 220's. The rest are simple 20 amp circuits. The lights are on completely unrelated circuits. They will all come into the breaker box via the bottom. I am interested in wiring them up so that whenever current is being drawn by any of the seven, the dust collector circuit will "sense" that a tool is on and then kick in the dust collector. Finally, it would be nice to make it so that the dust collector remains running for an additional 10 or 15 seconds after the tool is shut down. I wouldn't need to have all seven circuits hooked up this way maybe just four of the 20 amps and one of the 220's. With ample instructions I think I can handle the job myself. I'm not that familiar with relays but if you can point me to the parts I would need and give me some wiring tips I should be able to do this. At first I was just going to get one of those remote control gadgets from Penn State or wire in a half dozen 4-way switches scattered around the room but this solution would be neater and fully automatic.