DC fan and its working principle
In simple terms, a DC fan is a cooling fan that converts electrical energy into electromagnetic energy through DC voltage and electromagnetic induction, and then electromagnetic energy into mechanical energy, and finally into kinetic energy, so that the fan blades rotate.
The DC fan is mainly composed of four parts: rotor, stator, motor, and outer frame. as follows:
1. DC motor composition: it is composed of permanent magnet rotor, multi-stage winding stator, position sensor, and electronic commutation drive control circuit.
2. Rotor composition: It is composed of motor shell, permanent magnetic strip, shaft core and fan blades.
3. Stator part: enameled wire, plastic-coated silicon steel sheet, bearing, Hall sensor detection, drive circuit board and shaft.
The core components of the DC fan are the stator and transfer. We know from the ampere right-hand rule that a conductor passes current and a magnetic field is generated around it. If this conductor is placed in another fixed magnetic field, it will produce attraction or repulsion, which will cause the object to move. Inside the fan blade of the DC fan, a rubber magnet filled with magnetism is attached, surrounding the silicon steel sheet, and the shaft core part is wound with two sets of coils, and the Hall sensor component is used as a synchronous detection device to control a set of circuits. The circuit makes the two sets of coils wound around the shaft core work in turn, so that the silicon steel sheet produces different magnetic poles, and this magnetic pole and the rubber magnet generate repulsive force. When the repulsive force is greater than the static friction of the fan, the fan blades will rotate naturally. Due to the synchronization signal provided by the Hall sensor components, the fan blades can continue to operate, and the direction of rotation is determined by Fleming's right-hand rule. This is the working principle of a DC fan.