 By wiring the quadrature brushes together, current is produced in the armature, and the flux that this produces (A2) is again at right angles to the quadrature axis, resulting in an armature reaction which is directly opposed to the original excitation.This feature is fundamental to the machine, and does not depend on its direction of rotation.When the armature reaction is partially compensated by a compensation winding, the uncompensated portion of the armature reaction acts in this way.