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Changzhou High-Efficiency Motors Co., Ltd.
Changzhou High-Efficiency Motors Co., Ltd.

Precautions for Using Brushless DC Motors

At present, the operation of many devices will rely on brushless DC motors to complete. So in the process of use, what protection measures are usually taken for the safety of use and the protection of the motor?


Ⅰ. What details should be paid attention to when using brushless DC motors?


1. If the product has no special requirements, the brushless DC motor is not allowed to operate in the reverse connection system under the rated voltage. Because once the reverse connection operation is performed, the permanent magnet will be demagnetized. If it is necessary to operate in this way, a current limiting resistor must be added to limit the excessive current.


2. Pay attention to avoid demagnetization of permanent magnets caused by excessive current, temperature change and open circuit of magnetic circuit during disassembly and assembly, especially for alnico permanent magnet motors, magnetic short circuit protection is required during disassembly to avoid demagnetization.


3. When replacing the electric brush, it is necessary to clean the surrounding electric carbon dust first, and then use alcohol and gasoline to clean the commutator. At the same time, pay attention to no-load running-in when using new brushes.


4. When the load is too large or the power transistor is burned due to high current caused by improper use, a high-power transistor will be used for protection to protect the driver from being damaged due to the current exceeding the specification.


5. When the load of the brushless DC motor is not small, the energy sent back to the driver from the device end will endanger the driver when it stops rotating, so it needs to cooperate with the overvoltage protection circuit and the regenerative energy dissipation circuit to deal with it.


Ⅱ. What is the speed of the brushless DC motor related to?


The speed of the brushless DC motor is related to the frequency applied to the coil, provided that the brushless DC motor is powered by multi-phase pulses; If it is a brushless motor such as a stepping motor, its speed is related to the error signal received by the brushless DC motor, and its speed is proportional to the error signal; according to the calculation formula of the brushless DC motor's speed, it can also be known that its speed is related to the armature voltage, armature resistance and air gap main flux; if the motor voltage is constant In the case of a brushless DC motor, the speed of the brushless DC motor is affected by factors such as the magnetic flux and the number of turns of the coil; in addition, the speed of the brushless DC motor is also affected by factors such as the voltage, the coefficient of the motor structure, and the magnetic induction intensity. So what factors affect the speed of the brushless DC motor depends on the specific situation.