Motors that power ventilation cooling fans are usually divided into brushless motors or induction motors.

Brushless motors are sometimes called electronically commutated motors. Commutation refers to the act of switching the electrical connection from one motor winding to the next one. Motor windings in the DC cooling fan motor  is generally located in the stator or stationary portion of the motor. Then the rotor contains a magnet with alternating poles. (DC motor with the magnets in the rotor are sometimes called outrunner. There are other possible configurations but they are not as widely used as outrunners.)

The brushless DC fan motor uses an electronic controller to sequentially energize the stator windings, turning them into electromagnets, in a sequence that turns the rotor. First, one set of coils (that is, a coil and the coil located 180º away from it) would be energized to become electromagnets. This causes the opposite poles of the rotor and stator to be attracted to each other. As the rotor nears the energized coil, the next coil is energized and the coil nearest the rotor pole is switched off. As the rotor rotates near the next coil on the stator, the coil nearest the rotor pole is switched off. This sequence repeats as the rotor runs. The point to note is that there is always one set of coils pulling the rotor, causing it to rotate.

In fact, the set of coils behind the set pulling on the rotor is energized in a way that pushes on the rotor rather than pulls it. So there is a combined effect of pulling and pushing on the rotor which gives this motor high efficiency. The combined effect is that most of the coils in the stator act on the rotor nearly all the time.

One aspect of brushless motor operation is the necessity of knowing the position of the magnetic poles in the rotor. In order to fire the right stator coils at the right time, the controller must sense the position of the rotor. The controller reads the rotor position sensor to decide what coils to energize.

The usual way to sense the rotor position is with a Hall Effect sensor. It’s also possible to measure the back-EMF in the undriven coils to infer the rotor position, thus eliminating the need for separate Hall effect sensors, but that scheme is a bit more complicated. The efficiency of brushless motor is usually 85% to 90%, mainly because most of the energy entering the coil actually drives the rotor.

DC cooling fan has two positive and negative power lines. When installing the cooling fan, if the positive and negative lines are connected reversely by wrong operation, will the cooling fan burn out?

Whether the axial cooling fan is burnt out or not is mainly related to the IC Design of the cooling fan. In general, the drive IC with double wire winding method has internal protection design. If the positive and negative power lines are connected reversely, it will show the phenomenon of short circuit. At this time, the current of the cooling fan will be much higher than that under normal conditions. The motor current is large and its temperature rise is high. When the temperature reaches a certain degree, the driving IC will be damaged due to overheating and the cooling fan will be burned out.

Some of the single winding drive IC has no internal polarity protection. If the motor stator PCB is not designed with polarity protection, it may burn out the IC instantly when connected.

In order to prevent the ventilation cooling fan from burning out due to positive and negative polarity connection, a diode is added on the PCB of the cooling fan to design polarity protection, that is, when the polarity of the cooling fan is connected reversely, the current is zero, showing no power supply, so it can protect the cooling fan from burning out.

Cooling fans, as the name suggests, are used for ventilation and heat dissipation. It is widely used in various industries and fields, because in many electronic equipment and machinery, if there is no cooling device installed in the equipment, the working temperature may be too high, which may cause the performance of the equipment to decline, or even be damaged. For normal and efficient operation, a ventilation cooling fan is required. So where are the cooling fans commonly used in our lives?

In the field of home appliances, refrigerators, washing machines, smart toilets, air purifiers, humidifiers, dehumidifiers, etc. all need to be applied to cooling fans. These household appliances are often used, and through It is easy to generate heat when running on electric power, so it is necessary to use a cooling fan to help dissipate heat to prolong its service life.

In the field of medical treatment, during the normal use of medical equipment, under the action of current, the interior of the medical equipment will heat up to varying degrees. If the temperature exceeds the safe range under normal circumstances, install a cooling fan to ensure the normal operation of the equipment during use, which not only protects the service life of the equipment itself, but also improves the safety of the equipment.

In the field of vehicle system, automotive cooling fans are also installed on various parts of the car, and the phenomenon of converting mechanical energy into thermal energy also occurs during the driving process of the car. Therefore, the parts in the car also need to continue to be cooled, such as car seat cushions, LED headlights, etc. If there is no cooling tool, the parts of the car will naturally fail, causing the car to be sent to the maintenance department.

In addition, in addition to the above-mentioned household appliances, medical equipment and automobile fields, cooling fans are also widely used in many places, such as: office equipment (projectors, printers), power communication equipment (frequency converters, inverters, cabinets) and industrial equipment, etc.

Chungfo Electronic Technology Co., Ltd. focuses on the cooling needs of equipment in various industries. We are a cooling fan manufacturer specializing in R&D and supply of DC cooling fans, AC cooling fans and DC blower fans, etc. The product quality is excellent, the cooling fan gauge is complete, and the professional customization of cooling fans can be provided according to customer needs.

Why the speed of DC cooling fan slows down?

The speed of the cooling fan is determined by voltage, fan blade angle, diameter, number of fan blades, bearings, etc. So what is the reason why the cooling fan slows down?

The speed of the cooling fan is mainly determined by the structure and components of the fan itself, the bearing friction and the wind resistance of the inclination angle of the fan blade. If the air pressure of the cooling fan is not enough, the speed of the fan will also be affected.

1. The reason for the slow speed of DC cooling fan: first, check whether it has been used for too long. If it is not disassembled to clean the dust, there will be too much dust accumulation, which will make it difficult for the fan to rotate and slow down. It is recommended to clean regularly. Dust is very harmful to DC cooling fan.

2. The reason for the slow speed of DC cooling fan may also be the problem of power supply, so users can also consider replacing silent power supply or DC cooling fan. At present, there are many silent power supplies in the market, which can effectively reduce the power supply noise after strict testing. In addition, the DC cooling fan can be replaced better. The process of replacing the power fan is also very simple. The key is to pay attention to the connection between the fan and the power supply.

3. In addition, if the DC cooling fan is not installed and loosened during installation, the fan speed will also slow down. Therefore, it is recommended to be careful during installation and removal.

DC axial fan is made of PBT material. When it is working normally, the service life can be as high as 50,000 hours. The internal structure of the DC has a transformer and a main control board, which will not be affected by voltage fluctuations, so it is used Longer life.

High speed axial fan, its rotor contains DC cooling fan blades, which are the source of air activity, the fan axis, and are used to support the rolling of the balanced fan blades, the rotor magnetic ring, and permanent magnets. Ring frame, fixed magnetic ring.

In addition, DC cooling fan also includes a supporting spring, through which all the components and motors of the tube rolling are fixed, the rolling direction is produced, and the key to the size of the rolling speed can be activated. Its speed regulating performance is good, and the control is simple.

With the development of Internet information age, Industrial DC fans, Cooling fans, Cross flow fans and AC fans have been applied in many industries, such as household appliances, industrial equipment, electronic equipment, medical aviation and so on.

Have you ever encountered such a situation?

When the fan is used, the speed of the fan can meet the cooling requirements of the equipment, but when it is used for a long time, the speed of the fan will slow down.

What are the factors that make the speed of DC fan, Cooling fan, Cross flow fan and AC fan slow down?

1.First of all, fix the DC fan, Cooling fan, Cross flow fan and AC fan carefully when installing. If the fans are loose without fixing, the rotation speed of DC fan, Cooling fan, Cross flow fan and AC fan will also slow down.

2.Check the appearance of the fan for excessive dust accumulation, which makes it difficult for the fan to rotate. If there is resistance, the rotating speed will slow down. Therefore, pay attention to the environment of the fan and clean up the dust in time. In addition, a dustproof fan guard cover can be added to the fan, which not only enhances the fan air supply rate, but also functions to improve the overall performance of the fan.

3. The reason for the slow speed of the DC cooling fan may also be that there is a problem with the power supply, so users can also consider changing the silent power supply or cooling fan. There are many silent power supplies on the market at present, which are usually strictly tested and can effectively reduce the power supply noise. In addition, it can also change a better DC cooling fan for the power supply. The process of changing the power supply fan is also very simple. The key is to pay attention to the connection between the fan and the power supply.

Rotating speed is also one of the main parameters affecting the performance of cooling fans. Therefore, pay attention to check at any time!