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What is the working principle of the brushless DC motor?
Time：2017-03-26 13:58:46 View：0
Brushless DC motor is the use of semiconductor switching devices to achieve electronic commutation, that is, the use of electronic switching devices to replace the traditional contact commutator and brush. The utility model has the advantages of high reliability, no commutation spark, low mechanical noise, etc. the utility model is widely used in high-grade recording seats, video recorders, electronic instruments and automatic office equipment.
The brushless DC motor consists of a permanent magnet rotor, a multi pole winding stator and a position sensor. According to the change of the position of the rotor position sensor, along a certain order current to the stator windings of the converter (i.e. the detection of rotor position and stator winding and relative position of the sensing signal at a location determined by the signal conversion circuit after processing to control the power switch circuit of winding current switch according to certain logical relation). The working voltage of the stator winding is provided by the electronic switch circuit controlled by the position sensor output.
There are three types of position sensors: magnetic sensitive, photoelectric and electromagnetic.
The brushless DC motor magnetic sensitive position sensor, the magnetic sensor element (such as Holzer, Ci Min diode, magnetic sensitive element, transistor, magnetic resistor or ASIC etc.) mounted on the stator assembly, to detect a permanent magnet, when the rotor rotation magnetic field change.
The utility model relates to a brushless DC motor with a photoelectric position sensor, and a photoelectric sensor is arranged on the stator assembly according to a certain position. When the rotor rotates, because of the function of the shading plate, the photosensitive components on the stator will produce intermittent pulse signal according to a certain frequency. The brushless DC motor magnetic position sensor, is in the stator assembly is installed on the electromagnetic sensor components (such as coupling transformer, proximity switch, LC resonant circuit), when the permanent magnet rotor position changes, electromagnetic effect will cause the electromagnetic sensor generates high frequency modulation signal (the amplitude varies with the rotor position).