Brushless Small DC Electric Motor KG-3225-012 4500RPM Electric Tool

12v dc brushless motor

Drawings

Performance specifications

The Brushless DC motor power system consists of three parts: rotor, stator, and position sensor. Position sensing commutates the current of the stator winding in a certain order according to the changes in rotor position (that is, detects the position of the rotor magnetic pole relative to the stator winding, and generates a position sensing signal at the determined position. After being processed by the signal conversion circuit, the power switch circuit is controlled to switch the winding current according to a certain logical relationship). The working voltage of the stator winding is provided by an electronic switch circuit controlled by the position sensor output.

There are three types of position sensors: magnetic sensitive, photoelectric, and electromagnetic:

For Brushless DC motor with magnetic sensitive position sensor, its magnetic sensor components (such as Hall element, magnetic diode, magnetic sensitive pole tube, magnetic resistor or special integrated circuit, etc.) are installed on the stator assembly to detect the magnetic field changes generated when the permanent magnet and rotor rotate.

Brushless DC motor with photoelectric position sensor is equipped with photoelectric sensor on the stator assembly according to a certain position. The rotor is equipped with a light shield, and the light source is a light-emitting diode or a small bulb. When the rotor rotates, the photosensitive components on the stator will intermittently generate pulse signals at a certain frequency due to the effect of the shading plate.
A brushless DC motor using electromagnetic position sensors is equipped with electromagnetic sensor components (such as coupling transformers, proximity switches, LC resonant circuits, etc.) installed on the stator assembly. When the position of the permanent magnet rotor changes, the electromagnetic effect will cause the electromagnetic sensor to generate high-frequency modulation signals (whose amplitude changes with the rotor position).

Simply put, a Brushless DC motor relies on changing the alternating frequency and waveform of the current wave input to the stator coil of the brushless motor, forming a magnetic field that rotates fully around the geometric axis of the motor around the winding coil. This magnetic field drives the permanent magnet steel on the rotor to rotate, causing the motor to rotate. The performance of the motor is related to factors such as the number of magnetic steel, magnetic flux strength of the magnetic steel, and input voltage of the motor, It is closely related to the control performance of brushless motors, as the input is direct current, which requires an electronic governor to convert it into 3 alternating currents. It also requires receiving control signals from the remote control receiver to control the motor speed to meet the needs of model use.

Overall, the structure of brushless motors is relatively simple, and the real determinant of their performance is the brushless electronic governor (also known as electric governor). Good electric governor requires overall control of processes such as microcontroller control program design, circuit design, and complex processing technology, so the price is generally much higher than that of brushless motors.