Currently on the market.DC cooling fanThere are two types of self-monitoring methods: alarm sensor and speed sensor. The alarm sensor can give an alarm signal when the fan speed is lower than a certain threshold value, and the speed signal output can realize the real-time monitoring of the fan speed. Obviously, the greater the air volume, the higher the heat dissipation capacity of the DC cooling fan. This is because the heat capacity ratio of air is certain, and more air volume, that is, more air per unit time, can take away more heat. Of course, in the case of the same air volume, the heat dissipation effect is related to the way the wind flows.

The speed signal output from the fan circuit is usually in the form of pulses, and each wave head indicates that the fan has rotated one circle. Such a signal can be directly provided to the host for display through the data bus. The speed signal output by some fans is not the real speed of the fan, but a multiple of the speed. For example, 2, 4 or 6 pulses are generated per revolution, which must be processed to form a real speed signal reflecting the fan. To distinguish whether the fan speed is true or a multiple, use a tachometer to measure the actual speed and compare it with the displayed data.

The alarm signal output from the fan circuit has two states: "high level" and "low level". The meaning represented by the two levels is generally in accordance with the positive logic system. The high level indicates "fault" and the "low level" indicates "normal".

The speed signal output from the fan circuit is usually in the form of pulses, and each wave head indicates that the fan has rotated one circle. Such a signal can be directly provided to the host for display through the data bus. The speed signal output by some fans is not the real speed of the fan, but a multiple of the speed. For example, 2, 4 or 6 pulses are generated per revolution, which must be processed to form a real speed signal reflecting the fan. To distinguish whether the fan speed is true or a multiple, use a tachometer to measure the actual speed and compare it with the displayed data.

The speed measurement signal of the fan is generally output from a three-lead plug. The yellow and black of the three leads are +12V power supply and ground respectively, and the other color line is the speed signal output line. It should be noted that the third lead of some three-lead fans is not the speed signal output line, but the speed control signal line, through which the speed control signal is input to the fan motor.
The above is the cooling function of the DC cooling fan. For more details, please consult our official website!