1. the basic working principle of DC fan.
According to the principle of ampere's right side, when a conductor passes through a current, a magnetic field is generated around it. If the conductor is placed in another fixed magnetic field, a resistance effect will be generated, causing the object to move. In a pre-filled magnetic rubber permanent magnet ring (DC fan rotor), the number of magnetic pole pairs corresponding to the number of magnetic pole pairs filled with a permanent fixed silicon steel sheet (N,S,N ~).
The rotor (fan blade) is wound around the axis and the silicon steel sheet on the silicon steel sheet, and the Hall induction element is used as the synchronous detection device to control a set of circuits, which makes the two sets of coils on the silicon steel sheet work alternately. In this way, different magnetic poles on the outer surface of the silicon steel sheet (N,S,N,N,S ~) attract each other with the rubber magnet. If the repulsive force is greater than the static friction force of the fan, the rotor (fan blade) will rotate naturally. Because the Hall sensing device provides a synchronization signal, the fan blade can continue to work, and its direction of operation can be determined by the Fleming right-hand rule.
Fan energy conversion: electrical energy → electromagnetic energy → mechanical energy (kinetic energy) → thermal energy.
2. what is brushless DC fan (hereinafter referred to as DC fan)
Traditional DC motors must be equipped with brushes and commutators (commutators) to provide switching of currents in different directions and generate thrust to keep the motor running.
The brushless DC fan uses voltage as the DC voltage, so a fixed electronic switch (such as Hall induction element IC) is used to replace the brush to perform current conversion and make the rotor continue to work 」.
Brushless DC fan has the following advantages:
1 "no carbon brush wear, can run continuously for a long time, no maintenance.
3-2 inches is easy to run at high speed, with high efficiency and low noise.
3~3 "switch current without spark.