THE DRUM-WOUND ARMATURE consists of coils actually wound around the armature core so
that all coil surfaces are exposed to the magnetic field. Nearly all dc motors have drum-wound armatures.
MOTOR REVERSAL in a dc motor can be accomplished by reversing the field connections or by
reversing the armature connections. If both are reversed, rotation will continue in the original direction.
SPEED CONTROL IN A DC MOTOR is maintained by varying the resistance either in series
with the field coil or in series with the armature coil. Increasing shunt-field circuit resistance increases
motor speed. Increasing the armature circuit resistance decreases motor speed.