The proposed DC motor driver limits the amount of
current flowing into the motor. In other words, it can
maintains the armature current at a constant value although
applied voltage increased. When the armature current
remains constant, the internal generated voltage and therefore
the turning speed will increase propotional to the voltage
applied. Torque is directly proportional with the armature
current, so the ability in controlling the armature current
made torque control possible, as shown in the equation