What is a brushless DC fan of it, which is a lot of people want to know about a problem, the source of the Wind to give you a detailed explanation about the term, brushless DC electromagnetic drive through the conductor without contact, is driven by the magnetic field winding and not in contact there is no friction, long life, and low noise, the motor speed of the rotor by the stator and the rotor speed of the rotating magnetic field of the number of poles (P) Effect: n = 60 * f / P. In the case of a fixed number of rotor poles, changing the frequency of the stator rotating magnetic field can change the speed of the rotor. Brushless DC motor that is coupled to the electronic control synchronous motor (drive), control the rotation of the magnetic field of the stator and the rotor speed of the frequency of feedback to the control center repeatedly corrected in order to achieve close to DC motor characteristic ways. That brushless DC motor can remain within the rated load range when the load changes can be controlled to maintain a certain speed of the rotor. This is more in-depth answers, general non-professional services are not to know.