According to the different application environments, cooling fans can be divided into two categories: AC cooling fans and DC cooling fans. Mainly used for ventilation and heat dissipation of computer peripherals, household appliances, audio amplifier systems, car refrigerators, on-board equipment, instruments and mechanical equipment. AC cooling fans are generally used on large-scale equipment such as industrial machinery and medical equipment; DC cooling fans are generally used in small equipment fields such as electronic devices and appliances. Let’s take a look at the specific differences between DC and AC cooling fans:
Difference 1: Principle
The operating principle of a DC cooling fan: According to the right-hand rule of the ampere, a conductor passing through an electric current will generate a magnetic field around it. If this conductor is placed in another fixed magnetic field, it will generate suction or repulsion, causing the object to move. Inside the blades of the direct current cooling fan, a rubber magnet pre filled with magnetism is attached. Surrounding the silicon steel sheet, two sets of coils are wound around the axis, and a Hall sensing component is used as a synchronous detection device to control a set of circuits that rotate the two sets of coils wound around the axis. Silicon steel sheets generate different magnetic poles, which generate attraction and repulsion forces with rubber magnets. When the suction and repulsion force is greater than the static friction force of the cooling fan, the fan blades naturally rotate. Due to the Hall sensing component providing a synchronous signal, the fan blades can continue to operate, and the direction of their operation can be determined according to Fleming’s right-hand rule.
Operating principle of AC cooling fan: The AC fan operates directly through AC power supply. With a fixed AC frequency, the silicon steel sheet generates magnetic field switching, causing the cooling fan blades to generate torque and rotate. The higher the power frequency, the faster the magnetic field switching speed, and theoretically, the higher the speed of the AC cooling fan. But the frequency should not be too fast, as it will cause difficulty in activation.
Difference 2: Structure
There is a magnet inside the blades of the DC cooling fan, but there is no magnet in the AC cooling fan; The DC fan has a PCB board, while the AC fan does not; There may also be some differences in the external models of AC and DC; AC silicon steel sheets will be thicker than DC ones.
Difference 3: Parameters
The power consumption of DC cooling fans is much smaller than that of AC cooling fans, including current and voltage. The maximum speed that a DC fan can achieve will be higher than that of an AC fan.
Difference 4: Price
Compared to brand cooling fans of the same grade, DC cooling fans are generally more expensive than AC cooling fans, but they may not necessarily be. A DC fan with a size of 1751 or above is much more expensive than an AC fan.