The working principles of DC motor

DC motor inside the fixed ring permanent magnet, the current through the coil on the rotor to produce ampere force, when the rotor on the rotor and the magnetic field parallel, and then continue to turn the direction of the magnetic field will change, so the rotor at the end of the brush with the conversion The sheet is alternately contacted so that the direction of the current on the coil also changes, resulting in the direction of the Lorentz force unchanged, so the motor can maintain a direction of rotation.The working principle of the DC generator is to interpolate the armature coil in the alternating electromotive force,By the commutator with the brush of the commutation effect, so that when the brush from the brush leads to the principle of DC electromotive force.

The direction of the induced electromotive force is determined by the right hand rule (the magnetic induction line points to the palm of the hand, the thumb is pointing to the direction of the conductor movement, and the other four fingers are the direction of the induced electromotive force in the conductor).The direction of the force of the conductor is determined by the left hand. This pair of electromagnetic forces forms a moment acting on the armature, which is called the electromagnetic torque in the rotating motor, and the direction of the torque is counterclockwise in an attempt to turn the armature counterclockwise. If the electromagnetic torque can overcome the resistance torque on the armature (eg resistance torque caused by friction and other load torque), the armature can be rotated in a counterclockwise direction.