Paul,
This is very cool. The only thing I could suggest to improve it, and you can put it into the category of overkill, would be to have the switching gate enable and disable the appropriate outlet. That way you could only turn on the tool that was properly set up for dc and could not run a tool that didn't have the dc activated. Having written that, I will readily admit this is an elegant solution to a challenge many of us have when we want to rapidly switch from one tool to another. For example, I often use my older Rotex, which doesn't have a plug-it cord, to do the first grit or two of a sanding job and then follow with a 150/3 or other finish sander. Since I need to circumvent the Plug-it anyway, I just use a multiple outlet adapter on the DC outlet. I may just build something similar myself. (And I will probably configure it like yours and forego my own suggestion regarding the electrical switching. [unsure])
