High power to weight ratio due to high efficiency, compact disc shape and integral commutator. High reliability and rugged construction. There are no commutator connections to break down. Cross-connections are made at the armature periphery where cooling is at its maximum. Simple electronic control, as speed is proportional to voltage.
Maximum speed is self-regulating, regenerative braking is possible.
Constant speed 'shunt' characteristic. Will not over-speed on no load.