A footswitch for your router table is handy, but introduces a hazard since you could inadvertently step on the switch, or worse, kneel on it while trying to change a bit or something. To improve safety I built an interlock system that requires stepping on a footswitch
and pushing a momentary pushbutton to start the router. Since it's built with a micro-controller at the heart, feature creep is inevitable. I added a double-click button push to give a 5 second delay on router start. And why not control the shop vac? You don't want to start both at the same time and blow a breaker, so the vacuum has delayed start (and stop, since you still need to collect dust). Soft-start? Why not - reduces the starting surge.
Here's a shot attached to my router table:
More details can be found on my (new)
blog.