What Is The Root Cause Of DC Fan Noise?

1. Vibration
When the DC DC fan motor rotor is running, if the physical centroid of the motor rotor and the inertia force core of the transmission shaft are not on the same axis, it is easy to cause instability of the motor rotor. The close distance between the physical centroid of the motor rotor and the core of the shaft inertia force is called eccentricity. The instability of the motor rotor can also lead to axial force. When the motor rotor rotates, the Centripetal force creates a force on the shaft support point, producing vibration, which is transmitted to all components of the equipment.
2. Wind noise
When a DC fan is working, the leaves will periodically experience uneven single pulse force from the inlet and outlet airflow, causing noise. On the other hand, due to the uneven distribution of pressure between the leaves themselves and between them, the impact of rotation on the surrounding vapor and parts also forms rotational noise. In addition, when the vapor flows through the leaves, it also generates seepage barriers, vortices, and vortices to separate, causing pulse pressure distribution on the leaves and vortex noise. The noise generated by these three reasons can be referred to as "wind cutting noise". Generally, centrifugal fans with high exhaust volume and pressure have high cutting noise.
3. Abnormal noise
The DC fan message sounds like a single message, but the abnormal sound is different. During the operation of the fan, in addition to the message, if we have any other Chinese noises, we can make a judgment that a fan sound is abnormal. The buzzing sound may be caused by cultural collisions caused by the company's lack of dirt or deformation of the rolling bearings, improper assembly methods, and uneven winding of the motor winding, which in turn can cause looseness and may lead to abnormal noise due to development trends.
4. Service life
The service life of a DC fan refers to the normal operating time of the heat pipe radiator. The lifespan of high-quality goods can generally reach hundreds of thousands of hours. Because the price and characteristics are similar, selecting products with a long service life can clearly better maintain our own project investment. The service life of centrifugal fans is composed of many factors such as motor life, software environment, and power environment.
What are the differences between DC and AC fans?
1. The principle is different
DC DC fans are driven by the magnetic effect of AC voltage and current, which converts electromagnetic energy into mechanical kinetic energy and drives the fan blades to rotate. With the continuous conversion of electromagnetic coils and ICs, the magnetic induction core drives the fan blades to rotate.
The AC fan is driven by alternating current, and the working voltage alternates between positive and negative poles, without the help of circuit control, resulting in electromagnetic fields.
2. Different material properties
The DC DC fan is made of plastic material, and the internal structure of the DC motor includes a transformer and a main control chip (including variable frequency circuits, rectifier filters, operational amplifiers, etc.) that are not easily affected by voltage fluctuations, so its service life is very long.
The construction of AC fans is dominated by transformers, and most of the raw materials used for AC fans are made of domestically produced discharge pins, usually tungsten pins or stainless steel plates. If the working voltage fluctuates too much, it will affect the substation