Under normal circumstances, the DC cooling fan can adjust the speed by adjusting the magnetic field and armature voltage.

Armature is the component that plays the key and pivotal effect in the process of the motor completes the transformation of mechanical energy and electrical energy.

For a generator, it is a component that generates electromotive force, such as the rotor in a DC generator, and the stator in an AC generator.

For a motor, it is a component that generates electromagnetic force.

When choosing fans, you should know some necessary information, which can effectively help you choose products quickly.

1. The size of the fan.

2. Determine whether the fan is DC or AC.

3. The value of the supply voltage of the fan. Example: AC is 220V, 110V, 380V and DC is 5V, 12V, 24V, 36V, 48V.

4. The bearings of fans are ball bearings or sleeve bearings.

5. Airflow and speed of fan. For example, how many cubic meters per minute (CMM), or how many cubic feet per minute(CFM).

6. Pressure value.

7. Customer's special requirements for fans or parameters.

To solve this problem, we can try to use larger cooling fans. Under the condition of the same air volume, the working noise of the fan with large size at lower speed is smaller than that of the fan with small size at higher speed.

Another factor that we easily overlook is the bearing of the cooling fan. Because the rotating shaft and bearing collide with each other when the cooling fan rotates at high speed, it is also a main source of noise of the cooling fan.

The noise of cooling fan is related to friction and air flow. The higher the rotating speed and the larger the air volume of the cooling fan, the greater the noise will be.

In addition, if the fan bearing lacks lubricating oil or has too much dust, it will also cause fan noise, which needs to be maintained and cleaned in time, so as not to damage the hardware equipment due to blocked cooling.

Noise is the sound level generated by the cooling fan during operation, and its unit is decibel (dB). When measuring the noise of the cooling fan, it needs to be carried out in a silencing room with noise less than 17dB, one meter away from the fan, and aligned with the air inlet of the fan along the direction of the rotating shaft of the cooling fan.