Cooling fan speed and influencing factors
The speed of the cooling fan refers to the number of times the fan blades rotate per minute, and the unit is RPM. Rotational speed measuring instrument refers to a measuring tool for measuring the speed of an object. Generally, a digital display measuring instrument is used, as shown in the figure: The working principle of the cooling fan. When the cooling fan works, it mainly converts electrical energy into mechanical energy. The main principle is: when the cooling fan is powered, the fan coil has current. According to the right-hand rule of ampere, we know that a magnetic field will be generated around the coil, and a rubber magnet filled with magnetism is attached to the inside of the cooling fan blade. The magnetic field generated by the conductor and the fixed magnetic field generate repulsive force. When the repulsive force is greater than the static friction force of the fan (the friction force of the fan bearing, the wind resistance of the fan blade rotation), the fan blades rotate naturally. The DC fan has a fixed power supply voltage. It is necessary to use a Hall sensor component as a synchronous detection device to control a set of circuits so that the two sets of coils wound around the shaft can work in turn to generate different magnetic fields. Through the working principle of the fan, we know that the main conditions for determining the fan speed are the structure and components of the fan itself, the friction of the bearing and the wind resistance of the fan blade, and of course there are external factors. Let’s analyze it below: the cooling fan is passed Air cooling realizes heat dissipation. The main factor that affects air cooling heat dissipation is the environmental structure of the cooling system. When the system environment is relatively sealed, the air pressure of the fan should be considered when choosing a cooling fan. If the air pressure of the fan is not enough, the fan speed will be obvious. Affected, the air volume drops significantly, and the heat dissipation effect is not achieved. Therefore, the external wind pressure is a factor that affects the fan speed (supercharged cooling fans can overcome); there is also a more obvious factor is the external environment, such as sand, oily , High and low temperature and other environments, if the ordinary cooling fan is not protected, the harsh environment will also have a significant impact on its speed.