Patent Application
20190293076
The present invention relates to a control method for adjusting rotating speed of multiple fans according to temperature, and particularly to a method which realizes the control of rotating speed for one or more fans.
Nowadays, most servers or computer systems are equipped with fans for cooling, to avoid damaging the servers or computer systems due to overheating. Depending upon the change in temperature, the prior art utilizes a PWM (Pulsed Width Modulation) signal to adjust the PWM duty cycle of the fans, thereby increasing the air flow for cooling. However, each fan has its own characteristics. As shown in
The primary objective of the present invention is to provide a control method for adjusting the rotating speed of multiple fans according to temperature, wherein when a boot up system is activated, an MCU (Micro Controller Unit) outputs the signals of PWM duty cycle in an ascending or descending order. Next, after a while when the rotating speed tends to be stable, the fan speed is accessed by the MCU to build up a relation table of the PWM duty cycle with respect to RPM (Revolutions Per Minute). When the boot up system enters the run mode, the rotating speed and the corresponding PWM duty cycle can then be provided according to temperature. Therefore, the characteristics of each fan can be adjusted depending upon the change in temperature, which optimizes the cooling efficiency.
Referring to
Referring to
In step 401, it a fan speed table is determined, then it proceeds to step 408 proceeds and the run mode is entered; otherwise, step 402 proceeds.
In step 402, an initial PWM duty cycle is set up to increase the rotating speed, thereby increasing the air flow for cooling. Next, step 403 proceeds.
In step 403, the PWM signals are outputted to all the fans and then step 404 proceeds.
In step 404, a period of (N) time is waited and then step 405 proceeds.
In step 405, the PWM duty cycle of the fans is checked for the largest rotating speed. If the result is yes, then step 406 proceeds; otherwise, step 407 proceeds.
In step 406, a relation table of the PWM duty cycle with respect to the rotating speed (RPM) is built up (as shown in
In step 408, when the PWM duty cycle reaches 100% (the largest rotating speed), the recording stops and then the temperature controlled run mode is entered.
The abovementioned PWM duty cycle and the fan speed table can be used to build up the charts of the fan speed tables corresponding to the temperature trend as shown in
In step 407, if the rotating speed of the fans is not the largest speed, then the PWM duty cycle is increased. Next, step 403 is returned to output the PWM duty cycle to all the fans.
The abovementioned recorded data can be also used to check the failure condition of the fans. When the PWM duty cycle of one fan cannot reach the requested rotating speed, for example, the largest rotating speed can only reach 75%, the fan failure signal is produced to notify the boot up system. The abovementioned fan speed table data can be also recorded in an NVRAM (Non-Volatile Random Access Memory) 301 or a storage media, and is stored in the micro controller circuit board 100 (as shown in
In conclusion, according to the above description of the embodiments of the present invention, the present invention comprises an MCU circuit board and one or more fans. The MCU is activated and the PWM duty cycle is outputted to each fan in an ascending or descending order. After waiting for a period of time, the rotating speed is accessed and the server or computer system is operating. At this time, the rotating speed data is used depending upon the casing temperature, so that the rotating speed of each fan can be adjusted proportionally.
It is of course to be understood that the embodiments described herein is merely illustrative of the principles of the invention and that a wide variety of modifications thereto may be affected by persons skilled in the art without departing from the spirit and scope of the invention as set forth in the following claims.
