Rotation-speed controlling method for a fan

Abstract

The invention relates to a method for controlling rotation speed of a fan, applied in a system with a fan and a control chip connected with the fan, and it comprises the steps: the control system calculates the fan rotation speed needed by the equipment, according to the environmental temperature detected; the control chip outputs a control signal corresponding to the fan rotation speed to control the fan to rotate at a certain speed; it detects the fan rotation speed in a unit time and makes the fan rotation speed signal and the rotation speed control signal form a negative feedback; the control chip judges if the said fan rotation speed is in the allowed range: if yes, keep the current outputted rotation speed control signal so that the fan stably runs with the current rotation speed; otherwise, regulate the output control quantity to readjust the value of the fan rotation speed. By detecting the fan rotation speed signal and forming the said feedback, and using the control chip to regulate the fan rotation speed control signal to stabilize the fan rotation speed, it achieves the real-time and accurate monitoring and regulation for the fan rotation speed, and effectively reduces nonnormal fluctuation of the fan rotation speed, thus ensuring its control accuracy meets the control requirement for the fan rotation speed.

Description

technical field [0001] The invention relates to control technology in the field of electronics or communication, in particular to a fan speed control method. Background technique [0002] In communication equipment, fans are often used to cool the equipment to reduce the operating temperature of the equipment and ensure the normal operation of the equipment. And because the communication equipment is often in the same room as the computer room personnel, there are strict requirements on noise. Low fan speed can reduce noise, but the air flow is small and the heat dissipation effect is not good. Although the equipment operation requirements can be guaranteed at room temperature, as the ambient temperature rises or the system power increases, the fan speed needs to be increased accordingly. For some equipment The conflict between heat dissipation and noise requirements requires precise control of fan speed. However, due to problems such as voltage fluctuations and air duct b...

AI Technical Summary

Problems solved by technology

[0009] Because the speed control of this prior art is an open-loop control, the fan speed may fluctuate abnormally during actual operation, so that the temperature corresponding to the detected fan speed is inaccurate, so that the control chip outputs PWM that cannot reliably control the fan speed. pulse signal; in addition, this existing technology does not have the real-time speed detection function, the system cannot know the accurate speed value, and cannot adjust and convert the fan speed in a timely and accurate manner, thereby reducing the reliability of heat dissipation of the equipment

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