Thank you for all your replies.
From what i can read, the subjet is not so 'obvious'. Particularly as
we are working with the main line, it is not as easy as with low
voltage (OK, i know the principle as described previously : current
sensor, level detector, relay for switching and delay on swith off of
the router, sander ,...). So if we want a design working directly on
the main line voltage with few component, ... not so easy!
As i'm living in Europe and that it is almost impossible to receive
the WOODWORKER magazine, i would be very pleased to receive a copy
(scan on .pdf, .jpg, ...) of this particular article your are talking
about. I know it is not compliant with the copyright laws, but in my
particular situation, i think we can do an 'exeption'!
Many thanks by advance.