Is a brushless motor the same as a DC motor?
Misunderstandings about brushless motors
Many people have seen the brushless motor used in the model, they are all powered by batteries, so many people have always had such a misunderstanding in knowledge, thinking that the brushless motor is a DC motor, but it is not, the brushless motor is an AC motor, It is a kind of three-phase AC permanent magnet motor. The current input to the 3 wires of the model brushless motor is AC, but this AC is not a 50HZ mains sine wave, but from a brushless motor controller (commonly known as a brushless motor). The frequency of the three-phase alternating rectangular wave modulated is much higher than 50HZ, and it changes with the speed of the motor.
Brushless motor structure analysis
Structurally, the brushless motor is similar to the brushed motor, and also has a rotor and a stator, but the structure of the brushed motor is opposite; the rotor of the brushed motor is a coil winding, which is connected to the power output shaft, and the stator is a permanent magnet magnet. Steel; the rotor of the brushless motor is a permanent magnet magnet, which is connected to the output shaft together with the outer casing, and the stator is a winding coil. Brushless motor), then there is a problem now, without the transformation of the electromagnetic field, how to make the brushless motor rotate?
The simple operating principle of the brushless motor is simply, by changing the alternating frequency and waveform of the current wave input to the stator coil of the brushless motor, a magnetic field rotating around the geometric axis of the motor is formed around the winding coil, and this magnetic field drives the rotor on the rotor. When the permanent magnet magnet rotates, the motor rotates. The performance of the motor is related to factors such as the number of magnets, the magnetic flux of the magnet, and the input voltage of the motor. It is also closely related to the control performance of the brushless motor, because the input It is direct current, and the current needs an electronic governor to turn it into 3-phase alternating current, and it also needs to receive a control signal from the remote control receiver to control the speed of the motor to meet the needs of the model. In general, the structure of the brushless motor is relatively simple, and it is the brushless electronic governor that really determines its performance. A good electronic governor needs to have a single-chip control program design, circuit design, complex processing technology and other processes The overall control, so the price is much higher than the brushed motor.
