In article ,
"Jim Wilkins" wrote:

wrote
.... I don't buy that all you have to do is disconnect power,
-short the leads and the saw stops very quickly. That may
-have some effect, but I'd bet to stop it in even a few rotations
-requires some external power source.

-If anyone has an spec sheets or examples of saws, motors,
-etc with that feature I'd be interested in seeing them.

I just went down to the shop, turned on my grinder, then pulled the
plug and jammed the prongs against the metal outlet plate. There was
no spark or effect on the slowly decelerating wheel.
jsw

The open time was probably too long - humans are just not fast enough.

One classic way to rapidly stop an induction motor is to pass DC through
the windings. The DC establishes a field, causing large currents to be
induced in the squirrel cage. The DC source must be able to handle the
AC generated by the squirrel. About 10% of the nameplate AC voltage is
typical. This has the advantage of being insensitive to open time.

Joe Gwinn