Why brushed micro DC motors are more widely used

In daily life, all kinds of small household appliances and electronic products need to be powered by micro DC motors. Careful people will find that brushed micro DC motors are used in most products, such as coffee machines, shavers, etc. Shaver, facial cleansing instrument, beauty instrument, etc., these products rarely use brushless micro motors. Why?

We know that the brushless micro DC motor has high speed, low noise and long service life, while the brushless micro DC motor is slightly inferior to it. However, the brushed micro DC motor can be operated as long as the DC power is supplied, and the control is also very simple. It can be controlled only by increasing or decreasing the voltage. The brushless micro DC motor requires additional circuits to operate, and the torque is small when running at a low speed. If the torque is required, a reducer needs to be added, which has relatively high requirements on the design mechanism and cost of the product. The price of brushed micro motors will be more affordable.

The operation of the brushless micro DC motor generally requires three Hall sensors, because the three windings of the micro motor are at 120°, in order to measure the three positions of the corresponding rotor, three Hall sensors are needed, which are also mutually 120° distribution, in the wiring, a reverse Hall needs to be set in the middle of the two Halls, which can shorten the lead-out line. It should be known that the brushless DC motor does not have a brush device. The Hall sensor replaces the brush and the commutator, so it has high efficiency, low noise, high reliability, variable frequency speed regulation and long service life. Features of ultra-high speed.

To put it simply, in order for the DC motor to operate, there must always be a certain angle between the magnetic field of the stator coil and the magnetic field of the rotor permanent magnet. The rotation process of the rotor (that is, the process of changing the direction of the magnetic field) makes the two magnetic fields have an angle. After a certain degree, the magnetic field direction of the stator coil must be changed, and three Halls can be used to know the direction of changing the stator magnetic field, that is to say, the three Halls are the task of telling the controller when to change the current.

Therefore, most electronic products use brushed micro DC motors. The starting control method of brushless DC motors is too complicated. Unless it is a product with high parameter requirements, brushed micro motors cannot be used. Brushless DC motor.