On Jan 20, 1:42*pm, Tom Veatch wrote:


..."reversing polarity" of the brushes - which I interpret to mean
switching leads - won't have any effect on rotation direction of a
universal or any other type of AC motor. That would be no different
than reversing the plug in the wall socket.

On the other hand, breaking the motor open, and doing some internal
rewiring might accomplish the mission.

What I intended was to swap the wires to the two brushes
(this is easy to describe, there are other rewirings that would
accomplish the same thing). Because the brushes activate
the ROTOR magnetization, the swap would reverse the rotor
poles without changing the other magnetic part, the STATOR.
That accomplishes the reversal of a brush-type (universal) motor.

Think of the (temporary N) pole on the rotor, pulled clockwise;
if you make it instead a (temporary S) pole, the attraction
becomes repulsion and the motor goes counterclockwise.

Swapping the wall socket polarity would reverse both rotor
and stator fields, so has no effect on rotation direction.