Now that I've found an adaptor to connect my Wickes/Earlex vac to my circ saw, I was wondering...
You can get vacs with a socket outlet on, so you can plug a power tool into it. When you start the power tool the vac switches on, stopping the power tool switches off the vac.
I assume some kinda electronic gizmo senses the load and does the switching.
Can you buy said gizmo to fit to an existing vac?