Synchronous motor excitated magnet by direct current can make output mechanism specialities matched load specialities by means of adjusting exciting current to change magnetic field and power factor.

Put pulley and rotor of the centrifugal together and made full use of magnetic field, the centrifugal permanent-magnet direct-current generator reduces the cost.

The wiper motor is a permanent-magnet direct current (DC) one. It is equipped on the front windscreen glass with the mechanical parts of the worm gear.