What is the difference between a DC fan and an AC fan?


1. Working principle:

The working principle of a DC fan is that 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 to induce the magnetic ring to drive the blade to rotate.

The working principle of an AC fan: It is mainly driven by an AC power source, and the voltage will alternate between positive and negative. It does not rely on circuit control at all 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. However, the frequency cannot be too fast, because too fast will cause difficulty in starting.

2. Structure composition:

The rotor of the DC fan includes the fan blades of the DC cooling fan. It is the source of air flow and the axis of the fan. It is used to support the rotation of the balanced fan blades, the rotor magnetic ring, permanent magnets, and promote the magnetic level switching. , Fixed magnetic ring. In addition, it also includes supporting springs, through which the whole part and the motor part are fixed for the rotation of the tuberculosis, the direction of rotation is produced, and the rotation speed is key according to the size. Its speed regulating performance is good and the control is simple.



The internal structure of an AC fan (single-phase) is composed of two coil windings, one is the starting winding and the other is the running winding. These two windings are connected in series with each other, thus forming three points, the series point is the common end, the start winding end is the start end, and the running winding end is the run end. In addition, a starting capacitor is needed. The capacity is usually between 12uf and the withstand voltage is usually 250v. There are two connectors. One end is connected to the end of the starting winding and the other is connected to the end of the running winding to form a triangular power supply (no need to distinguish live wires The neutral wire) is connected to the end of the running winding (that is, connected to one end of the capacitor), and the other is connected to the common terminal. The ground wire is connected to the motor casing.

3. Material characteristics:

DC fan material: it is made of alloy material, and its life can be used continuously for more than 50,000 hours. The internal structure of DC has a transformer and a main control board (including frequency conversion circuit, rectifier filter, amplifying circuit, etc.), which will not be affected by voltage fluctuations. Long service life.

The internal structure of the AC fan is mainly a transformer. Most of the materials used for AC fans are 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.