There are also brushless DC motors in large motors. Welcome to wholesale big motor
Brushless DC motors use semiconductor switching devices to realize electronic commutation, that is, electronic switching devices are used to replace traditional contact commutators and brushes. It has the advantages of high reliability, no reversing sparks, and low mechanical noise. It is widely used in high-end audio jacks, video recorders, electronic instruments and automated office equipment.
The brushless DC motor is composed of a permanent magnet rotor, a multi-pole winding stator, and a position sensor. Position sensing commutation of the stator winding current in a certain order according to the change of the rotor position (that is, detecting the position of the rotor pole relative to the stator winding, and generating a position sensing signal at a certain position, which is processed by the signal conversion circuit To control the power switch circuit, 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. Brushless DC motors using magnetic-sensitive position sensors, whose magnetic-sensitive sensor components (such as Hall elements, magneto-sensitive diodes, magneto-sensitive pole tubes, magneto-sensitive resistors or application-specific integrated circuits, etc.) are mounted on the stator assembly. To detect the change of the magnetic field generated when the permanent magnet and the rotor rotate.
The brushless DC motor with photoelectric position sensor is equipped with a photoelectric sensor in a certain position on the stator assembly, a light shield is installed on the rotor, and the light source is a light emitting diode or a small bulb. When the rotor rotates, the photosensitive components on the stator will generate pulse signals intermittently at a certain frequency due to the effect of the light shield.
Brushless DC motors with electromagnetic position sensors are equipped with electromagnetic sensor components (such as coupling transformers, proximity switches, LC resonance circuits, etc.) on the stator assembly. When the position of the permanent magnet rotor changes, the electromagnetic effect will cause the electromagnetic sensor Generate a high-frequency modulation signal (its amplitude varies with the rotor position).
