Different principles
1. The principle of the brush motor: the brush motor uses mechanical equipment to reverse, the magnetic pole does not move, and the coil rotates. When the motor is working, the coil and commutator rotate, the magnetic steel and carbon brush do not rotate, and the alternating change of coil current direction is completed by the commutator and brush that the motor rotates.
2. Principle of brushless motor: brushless motor adopts electronic commutation, the coil does not move, and the magnetic pole rotates. Brushless motor uses a set of electronic equipment to sense the position of permanent magnet magnetic pole according to Hall element. Based on this perception, the electronic circuit can timely switch the direction of current in the coil to ensure the correct direction of magnetic force to drive the motor. It eliminates the shortcomings of brush motor. The brushless motor controller can also achieve some functions that cannot be achieved, such as adjusting the power switching angle, braking motor, reversing motor, locking motor, and using braking signal to stop motor power supply.
Difference of speed regulation mode
In fact, the control of both motors is pressure regulation, but because brushless DC uses electronic commutation, it can achieve digital control. Brushing is directly based on the direction of the carbon brush. Traditional analog circuit control is relatively simple.
1. The speed regulation process of the brush motor is to adjust the voltage of the power supply. The adjusted voltage and current will change the magnetic field intensity generated by the electrode according to the conversion of the commutator and the brush to achieve the purpose of changing the speed. This process is called variable voltage speed regulation.
2. The speed regulation process of brushless motor is to change the control signal of electrical regulation when the power supply voltage of the motor remains unchanged, and then change the switching speed of high-power MOS tubes according to the microprocessor to achieve the speed change. This process is called frequency conversion speed regulation.
3、 Advantages of brushless motor
The direct change of brushless motor is that there is no electric spark generated during the operation of brushless motor, which will greatly reduce the interference of electric spark to remote control radio mechanical equipment.
The brushless motor has no brushes, so the friction is greatly reduced during operation, the operation is smooth, and the noise is much lower. This feature is a huge support for the reliability of the model operation.
Without brush, the wear of brushless motor is mainly on the bearing. From the perspective of mechanical equipment, brushless motor is almost a maintenance free motor. If necessary, only some dust removal and maintenance are required.
Source: Lightning Eight Diagrams