1、 What is a brushless DC motor? A brushless DC motor consists of a motor body and a driver, and is a typical mechatronics product. Due to the fact that brushless DC motors operate in a self controlled manner, they do not add additional starting windings to the rotor like synchronous motors that start with heavy loads under variable frequency speed regulation. Brushless DC motors also do not experience oscillations and out of step during sudden load changes. Brushless DC motors are permanent magnets for small and medium-sized brushless DC motors, and now they mostly use high magnetic energy product rare earth neodymium iron boron (Nd Fe B) materials. Therefore, the volume of rare earth permanent magnet brushless DC motors is reduced by one frame number compared to three-phase asynchronous motors of the same capacity. 2、 The working principle of brushless DC motors is that brushless DC motors use semiconductor switching devices to achieve electronic commutation, that is, brushless DC motors use electronic switching devices to replace traditional contact commutators and brushes. Brushless DC motors have the advantages of high reliability, no commutation sparks, and low mechanical noise. Brushless DC motors are widely used in high-end recording consoles, video recorders, electronic instruments, and automated office equipment. A brushless DC motor is composed of a permanent magnet rotor, a multipole winding stator, a position sensor, etc. Brushless DC motor position sensing is based on changes in rotor position, The brushless DC motor commutations the current of the stator winding in a certain order (the brushless DC motor detects the position of the rotor magnetic pole relative to the stator winding, and generates a position sensing signal at the determined position. The brushless DC motor is processed by the signal conversion circuit to control the power switch circuit, and the brushless DC motor switches the winding current according to a certain logical relationship). The working voltage of the stator winding of a brushless DC motor is provided by an electronic switch circuit controlled by the position sensor output.

      There are three types of brushless DC motor position sensors: magnetic sensitive, photoelectric, and electromagnetic. Brushless DC motors use magnetic sensitive position sensors for brushless DC motors. Brushless DC motors use magnetic sensitive sensor components (such as Hall elements, magnetic diodes, magnetic sensitive diodes, magnetic sensitive transistors, magnetic resistors, or specialized integrated circuits). Brushless DC motors are installed on stator components, and are used to detect changes in the magnetic field generated by the rotation of permanent magnets and rotors. The brushless DC motor adopts a photoelectric position sensor based brushless DC motor. The brushless DC motor is equipped with photoelectric sensor components at a certain position on the stator component, and the rotor of the brushless DC motor is equipped with a light shield. The light source of the brushless DC motor is a light-emitting diode or a small light bulb. When the rotor of a brushless DC motor rotates, the photosensitive components on the stator of the motor will intermittently generate pulse signals at a certain frequency due to the effect of the shading plate. The brushless DC motor adopts an electromagnetic position sensor based brushless DC motor. The brushless DC motor 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 of brushless DC motor will cause the electromagnetic sensor to generate high-frequency modulation signals (the amplitude of brushless DC motor varies with rotor position).