What are the differences between a DC cooling fan and an AC cooling fan

The cooling fans mainly include DC cooling fans and AC cooling fans, so what is the difference between them? 1. Working principle: The working principle of the DC heat dissipation fan: through DC voltage and electromagnetic induction, electrical energy is converted into machinery to drive the rotation of the blade. The coil and IC are continuously switched, and the induction magnetic ring drives the rotation of the blade. The working principle of the AC cooling fan: It is driven by AC power, the voltage will alternate between positive and negative, and it does not rely on circuit control to generate a magnetic field. The frequency of the power supply is fixed, and the change speed of the magnetic pole generated by the silicon steel sheet is determined by the frequency of the power supply. The higher the frequency, the faster the magnetic field switching speed, and the faster the rotation speed in theory. However, the frequency cannot be too fast, too fast will cause difficulty in starting. 2. Different materials: The outer frame of the AC cooling fan is generally aluminum, while the outer frame of the DC cooling fan is a plastic frame. The ability to withstand high temperatures is different, and the AC is better. 3. Different air volume: cooling fans of the same size , Because the motor of the AC cooling fan is large, the fan blade is short and the DC cooling fan is just the opposite. The fan is long and the motor is small, so the air flow per unit area is more, the air volume is larger, and the heat dissipation capacity is better. 4. Structure composition: 　　DC Cooling fan: The rotor of the DC cooling fan includes the fan blades of the DC cooling fan, which are the source of air flow and the axis of the cooling fan, which is used to support the rotation of the balanced fan blades, the rotor magnetic ring, and the permanent magnets to promote the magnetic level switching speed The key, magnetic ring frame, fixed magnetic ring. In addition, it also includes supporting springs. Through these parts, the whole part and the motor part are fixed to rotate the tuberculosis, and the direction of rotation is produced, and the speed of the active and large rotation is critical. Its speed regulating performance is good and the control is simple. AC cooling fan: The internal structure of the AC cooling fan (single-phase) is composed of two coil windings, one is the start winding, and the two windings are connected in series to form three points. The series point is the common end. The end of the starting winding is the starting end. The end of the starting winding is the running end. In addition, a starting capacitor is needed, usually between 12uf and 250v withstand voltage. There are two connectors, one end is connected to the end of the starting winding and the other is connected to the running winding. The end of the power supply (no need to distinguish between the live line and the neutral line) is connected to the end of the running winding (that is, it is also connected to one end of the capacitor), the other is connected to the common end, and the grounding wire is connected to the motor housing. 5. Material characteristics: 　　　　 DC cooling fan: It is made of alloy material, and the life span can be used continuously for more than 50,000 hours. The internal structure of the DC has a transformer and a main control board (including frequency conversion circuit, rectification filter, amplifying circuit, etc.), which will not be affected by voltage fluctuations The impact of this, so its service life is longer. AC cooling fan: The internal structure of the AC cooling fan is mainly a transformer. Most of the materials used for the AC cooling fan are made of domestic discharge needles, usually tungsten needles or stainless steel materials. If the voltage fluctuates too much, it will affect the service life of the transformer .