The operational mechanism of DC motor with selfcontrolled frequency was explained at first. Sense on polar daxis was a prerequisite for selfcontrolled phase of armature current. Reform and evolution of the position sensor may be regarded as a mark of development on DC motor less commutator. The commutatorless motor was the forerunning of the development on DC motor less commutator. The successor was the motor system with selfcontrolled frequency consisted of the motorbody with sinusoidal current, including application of the transvector control technique. Sense on position and speed of polar daxis in order to selfcontrol the phase of armature current or voltage with the help of computerassisted controlling technique may be developed hereafter. It would gave an impetus to progress towards deepened development on DC motor less commutator. However, the outcome of development becomes of the generalized dc motor rather than synchronous motor.