Re: [A/S] Re: New Suburban furnace VS catalitic

["Dr. Gerald N. Johnson, electrical engineer" <geraldj@xxxxxxxx>]

A DC motor with wound field and rotor will run the same direction if the
polarity of the leads are swapped because that changes the polarity of
both the field and armature. A permanent magnet motor is more typical of
a modern motor and since the field is that permanent magnet, rotor
direction is changed by changing the polarity of the armature. Very few
motors change the direction of rotation by moving the brushes.

Gerald J.