China Neodymium And Ferrite Magnets Manufacturer & Supplier 
The magnetic pole pairs of brushless motors are mainly detected by the changes in the magnetic field of the rotor poles. The rotor magnets (magnetic steel) are arranged alternately in N and S poles. When the brushless motor Hall detects that the magnet jumps from N pole to S pole, or S pole to N pole, the output of Hall will have corresponding high and low level changes. This means that the position of the rotor has changed, and whether the brushless motor winding is energized does not affect Hall detection.
When the number of poles of a brushless motor is constant, changing the frequency of AC can change the synchronous speed of the rotating magnetic field, which is the basic principle of variable frequency speed regulation. Due to the fact that the magnetic poles of a motor appear in pairs, they are often represented by magnetic pole pairs.
Brushless motors use Hall elements to induce changes in the magnet, determine the position of the magnetic pole pairs of the brushless motor, and drive the rotor of the brushless motor to achieve magnetic field speed and pole number detection through a controller.
Brushless motor rotor neodymium magnet;
Several methods for detecting the number of magnetic poles of brushless motor;
1. Observe the appearance: Usually, the appearance of the brushless motor will show the number of magnetic poles. The magnetic poles usually appear as blocks of magnets surrounding the rotor, and the number of magnetic poles can be determined by counting these blocks.
2. Rotor shape: The shape of the rotor can also provide some clues. For example, a rotor may have a series of bumps, each corresponding to a magnetic pole. By counting these bumps, the number of magnetic poles can be determined.
3. Test instrument: Use a special test instrument to detect the number of magnetic poles. These instruments are often called pole meters or magnetic field gauges, and they determine the number of magnetic poles by measuring the magnetic field generated by the motor. During the test, the instrument detects changes in the magnetic field around the rotor and calculates the number of magnetic poles.
Note: The number of magnetic poles of a brushless motor is determined during the design and manufacturing process, and does not usually change during the use of the motor. Therefore, in practical applications, the number of magnetic poles is usually known. If you need to know the number of magnetic poles for a particular motor, it is best to refer to the technical specifications of the motor or the information provided by the manufacturer.
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