The working principle of the DC generator is to change the electromotive force in the armature coil, and rely on the commutation action of the commutator with the brush, so that it becomes the principle of the DC EMF from the brush end.
The direction of the inductive electromotive force is determined by the right-hand rule (the magnetic line points to the palm of the hand, the thumb pointing to the direction of the conductor's movement, and the other four points are the direction of the inductive electromotive force in the conductor).
The direction of the conductor's force is determined by the left-handed rule. This pair of electromagnetic force formed a torque in the armature, which is called the electromagnetic torque in the rotating motor, the direction of the torque is counterclockwise direction, attempting to rotate the armature counterclockwise. If the electromagnetic torque is able to overcome the resistance torque on the armature (such as the resistance torque caused by friction and other load torque), the armature can rotate counter-clockwise.
DC Motor is a motor that relies on direct current operating voltage, which is widely used in tape recorder, VCR, DVD player, electric shaver, hair dryer, electronic watch, toy, etc.