automation for dust collector

["Hank" <HankBrandenburg@xxxxxxxxx>]

I have a wood shop in my basement and would like to automate the
startup/shutdown of my dust collector unit.  It is a 220v unit plumbed
to 4 separate power tools (3 are 110v, 1 is 220v).  My ideal
configuration would be to have the dust collector start immediately
when any of the 4 tools are powerd on, and remain on for a few seconds
after the tool is turned off.

I have been using a keychain remote control with an X10 system to
manually control the unit.  For some reason I just fried the 2nd
appliance control module since I've had the system.  Instead of
replacing the manual system I am hoping to automate.

I am familiar with electronics, including relays and timer circuits,
and am interested in any sugggestions on how to accompish this task.
In particular, is there a way to detect when the motor in any of the
tools starts without having to wire directly into the switch?  Is there
a way to do this without running additional wiring to all of the tools?

Thanks in advance for any advice/guidance!