The brushes are positioned such that they make contact with those commutator segments that are connected to coils that are
moving through a magnetic neutral point between poles of the machineâ€™s field flux. As a result, all coils making up one parallel path are always moving under a north magnetic pole, and the others are always moving under
a south magnetic pole. The movement of the commutator contacts underneath the brushes automatically switches a coil from one path to the other as it moves from a north pole region to a south pole region. Since the coils in both paths move in the same direction, but through opposite flux regions, the voltages induced in the two paths are opposite. Consequently, the positive and negative ends of each path occur at the same points in the series loop, which are at the points where the
brushes contact the commutator. The brush positions, thus, represent a unidirectional (or DC) connection to the rotating coil.