Views: 158 Author: Site Editor Publish Time: 2020-09-03 Origin: Site
Centrifuge: the difference between brushed and brushless motors
The so-called brushless motor means no brush! Its no-load resistance mainly comes from the rotating contact point between the rotor and the stator, so the general brushless motor uses ball bearings at both ends of the rotor to reduce friction! In this way, the centrifuge will not have a lot of frictional resistance and heat (in fact, it will still generate heat, but the heat source comes from the resistance loss on the coil), and has extremely high (80%-90%) efficiency and high speed! Generally used in models that require high power output, providing excellent and strong power!
The so-called motor is the main part of the centrifuge, which can be divided into brush, brushless and frequency conversion. The two brushes (copper brush or carbon brush) of a brushed motor are fixed on the back cover of the motor through an insulating seat and directly introduce the positive and negative poles of the power supply to the inverter of the rotor, and the inverter connects the coil on the rotor , The alternating polarity of the 3 coils and the 2 magnets fixed on the housing form a force to rotate. Since the inverter is fixed with the rotor, and the brush is fixed with the housing (stator), the brush and the inverter continue to rub against when the motor rotates, generating a lot of resistance and heat. Therefore, the efficiency of the brush motor is low and the loss is very large. But it has the advantages of simple manufacturing, low cost!
Some people often call DC brushless motors, but in fact, the brushless motors used in the model are 3-phase AC motors. Then why can we use ordinary DC power to drive him? The secret lies in the brushless electronic governor we use! The fundamental difference between the brushless electronic speed controller and the brushed electronic speed controller is that the brushless electronic speed controller converts the input DC power into a three-phase AC power source to provide power for the brushless motor.
So, when it comes to brushless motors, we have to care about its KV value. KV is a rotation speed unit equivalent to RPM/V, which is the no-load rotation speed for every minute obtained for every 1V voltage. Speed = KV value * voltage.