DC cooling fanThe power supply is DC, and the AC cooling fan is AC. Unlike the DC fan, the power supply voltage is fixed. It must rely on circuit control to make the two sets of coils work in turn to generate different magnetic fields. The AC fan has a fixed power supply frequency, so the magnetic pole change speed generated by the silicon steel sheet is determined by the power supply frequency. The higher the frequency, the faster the magnetic field switching speed, and theoretically the faster the speed, just like the principle of the faster the number of DC fan poles. However, the frequency should not be too fast, too fast will cause difficulty in activation.
The main application of the two: the operation mode of the DC cooling fan is that the motor runs with permanent, built-in magnets, relying on the magnets to attract and repel the rotor to produce operation.
AC cooling fans are often used in equipment that requires stable and stable air volume, such as home appliances, air conditioning systems, and industrial equipment. Among them, industrial equipment is most widely used in switchboards such as machine tools, industrial electric heating equipment, and automatic control systems.
The advantages of DC cooling fans: 1. Minimally small electromagnetic interference; DC cooling fans have less electromagnetic interference, which can reduce electromagnetic interference while preventing overheating 2. Low energy consumption; generally 50% energy saving compared with cooling fans
    
The advantages of AC cooling fans: provide stable and continuous air volume, can exhaust hot air, and inhale colder air

Disadvantages of DC cooling fans: 1. The air volume changes and is uneven; The main disadvantage is that it cannot provide direct and continuous air volume. 2. Transformers (rectifiers) may be required.
-The AC fan uses alternating current, and the current will change direction;
-DC fans use direct current and only have unidirectional current.
-Therefore, the DC fan must use a transformer (rectifier) to convert alternating current into direct current to make the fan.