Emmanuel,
That's close.... but the unit I'm talking about allows any tool plugged into any socket in that particular electrical circuit to power-on the dust collector system. I guess it's like what you found except it's hardwired into the circuit, not a plug-in unit. It must sense a draw in the line or however the CT's do it. I don't know; I'm a plumber, not an electrician.
I was searching last night and I did come upon a system where opening any blast gate in the duct line would power up the dust-collector. May actually be the best thing for my situation. You see, my garage only serves as storage for all the tools jigsawed into every available nook & cranny, and the stationery tools get rolled out onto the 8' x 30' concrete slab outside the get used; the rest of the driveway is gravel... To minimize the amount of extension cords on the ground, I run a single 220v cord out, plug into a box with four 220v outlets & eight 110v outlets, and cluster everything with a 4" dust port around that and the Delta dust collector and keep as short a hose run as possible to the Delta 15" planer, Powermatic 6" Jointer, Performax 16-32 drum sander and Williams & Hussey Moulder/Planer to avoid tripping on it all. Right now, I just run one hose and move it to whatever tool I'm about to use. Branching off to all these tools and using blast gates to trigger the dust collector may just be the best bet yet. Or at least until I find that five acres in Northen California with a big enough barn to turn my tool collection into a four-seasons workshop. The biggest complaint with my Shop Fox system is that I sometimes forget to press the remote to start the dust collector prior planing and finally remember when shavings start blowing out the back. Or remembering to turn it on but forgetting to move the hose from the planer to whatever I've moved on to. Boy, it's tough getting old.... but then, just consider the alternative....
Gary