When purchasing brushless DC motor, which aspects should we start from? What problems should we pay attention to? Next, qiwo motor will introduce to you. When purchasing brushless DC motor, we may as well compare it to see if it is useful.

　　First of all, let's make a little popular science

　　Brushless DC motor is composed of permanent magnet rotor, multipole winding stator and position sensor. According to the change of rotor position, the position sensor commutates the current of stator winding in a certain order (that is, it detects the position of the rotor pole relative to the stator winding, generates the position sensing signal at the determined position, and then controls the power switch circuit after processing by the signal conversion circuit, and switches the winding current according to a certain logical relationship).

　　Brushless DC motor uses semiconductor switching devices to realize electronic commutation, that is, electronic switching devices replace the traditional contact commutator and brush. It has the advantages of high reliability, no commutation spark and low mechanical noise. It is widely used in high-end recording stands, video recorders, electronic instruments and office automation equipment.

　　The following introduces the matters needing attention in the purchase of Brushless DC motor:

　　1. Current of Brushless DC motor

　　If the rated input current IR (a) of the motor is selected, the peak current IP (a) = 2xir. Otherwise, there is no engineering margin for the output current of the driver. If the rated output power (or maximum output power) pr (W) and driving voltage VR (V) of the motor are known, the peak current IP (a) ≥ 4xpr / VR

　　2. Voltage of Brushless DC motor

　　The voltage is provided by an electronic switch circuit controlled by the output of the position sensor. To select brushless DC motor products, the correct voltage should be selected first. According to the needs of customers, the rated voltage should be selected to select the voltage parameters of the driver. The voltage used should not exceed the range specified by the driver in the process of no-load and full load.

　　3. Pay attention to the service temperature of Brushless DC motor

　　We can also set the motor according to the parameters, but we need to set the suitable parameters according to different motors. Of course, we also need to consider the temperature range. The wider the temperature, the higher the price.

　　4. Pay attention to the resistance of Brushless DC motor

　　According to the requirements of power insulation, in order to ensure the normal operation of the driver, the insulation resistance between the hall line ground wire and the motor winding wire of the motor, and between the hall ground wire winding wire and the shell is greater than 100 megohm 500VDC, which can withstand 600vac / 50 Hz / 1 MA / 1 second voltage without breakdown.

　　Special attention: the driver brake of Brushless DC motor adopts short circuit brake at the motor end, so the motor has braking force when it is running, and there is no braking force when it is not running. The higher the speed is, the greater the braking force is. Because the brake current does not pass through the current sensing resistor, the brake current cannot be controlled. Therefore, when braking, the speed should not exceed the safe braking speed, otherwise the power tube may be burnt out. Please use this function carefully.