TWI608319B - Method for robust-controlling rotating speed of fan - Google Patents

Description

Robust fan speed regulation method

The invention relates to a fan speed control method, and in particular to a two-stage fan speed control method.

Most electronic devices are equipped with a fan to facilitate smooth heat dissipation of the electronic device. The traditional fan control method is to detect the ambient temperature around the electronic component or the fan, and increase the rotational speed of the fan by increasing the fixed rotational speed per unit time when the ambient temperature is increased. However, if the speed of the fan is increased in a large amount per unit time in order to rapidly improve the heat dissipation effect, high-frequency sound waves are generated, causing discomfort to the user; however, if the frequency of the high-frequency sound waves is avoided, only the fan is slightly increased per unit. The speed of the time increases the overall antipyretic time, and the electronic components may be damaged by prolonged high heat operation.

Secondly, the method of increasing the rotational speed of the fan by increasing the fixed rotational speed per unit time does not allow the target rotational speed value of the fan to achieve the antipyretic effect to be exactly an integral multiple of the fixed rotational speed per unit time. Therefore, in order to reach the target speed value, the fan speed must be exceeded to exceed the target speed value to provide a certain amount of heat-dissipating capability, and then the fan speed per unit time is successively reduced to make it approach the target speed. The value, the corresponding fan speed versus time diagram is shown in Figure 1. Although such a fan control method can provide an antipyretic effect, it takes a long time to reach the target rotational speed.

Moreover, the conventional fan control method can only adjust the rotation speed of the fan by temperature, and when a plurality of fans are simultaneously provided in the electronic device, the fan cannot be shipped for each fan. The set value provides a different adjustment, resulting in insufficient flexibility in use.

According to the present invention, a robust fan speed control method is provided for shortening the fan speed increase time and overcoming the high frequency sound wave when the fan speed is increased; in addition, the robust wind speed control method of the present invention is also used to overcome the conventional fan The problem of differentiated regulation based on the factory setting values.

A method for controlling the speed of a robust fan according to the present invention includes the steps of: detecting a rotation speed of a fan by using a rotation speed sensing unit, and generating a fan rotation speed value; comparing a fan rotation speed value with a target rotation speed value by using a micro processing unit, and When the fan speed value is different from the target speed value, the driving unit outputs the first driving signal for the first predetermined time to increase the fan speed value by the first speed value per unit time, and then outputs the second predetermined time. The second drive signal causes the fan speed value to increase the second speed value per unit time, wherein the first speed value is greater than the second speed value.

The robust fan speed control device of the invention can effectively shorten the time for increasing the fan speed, and can avoid the high frequency sound waves generated when the fan speed increases, and can also be differentiated according to the factory setting value of each fan, and can provide Control flexibility.

10‧‧‧Microprocessing unit

12‧‧‧Speed sensing unit

14‧‧‧ drive unit

16‧‧‧Temperature sensing unit

18‧‧‧ Input unit

3‧‧‧Fan

L1‧‧‧ first line

L2‧‧‧ second line

S100-S108‧‧‧Strong fan speed control steps

t1‧‧‧First scheduled time

T2‧‧‧second scheduled time

T3‧‧‧ time difference

1 is a circuit diagram of a conventional fan speed control device; FIG. 2 is a circuit block diagram of a robust fan speed control device according to the present invention; FIG. 3 is a flow chart of a method for regulating a robust fan speed according to a first embodiment of the present invention; 4 is a flow chart showing a method for adjusting the rotational speed of a robust fan according to a second embodiment of the present invention; and FIG. 5 is a diagram showing the relationship between the rotational speed of the fan and time according to the present invention.

The invention provides a method for controlling the speed of a robust fan, which first senses the rotational speed of the fan by using a rotational speed sensing unit and generates a fan rotational speed value. The micro-processing unit is then used to compare the fan speed value with the target speed value. Fan speed value and target When the rotational speed values are different, the micro processing unit causes the driving unit to output the first driving signal for a first predetermined time, so that the fan rotational speed value increases by a first rotational speed value per unit time, and then outputs the second second predetermined time. The driving signal increases the fan speed value by a second speed value per unit time, and the first speed value is greater than the second speed value.

Based on the foregoing, the specific embodiments are set forth below and described in detail with reference to the drawings.

2 is a circuit block diagram of a robust fan control device of the present invention. The robust fan control device is configured to sense the rotational speed of the fan 3 and adjust the rotational speed of the fan 3 according to the rotational speed parameter value, for example, the ambient temperature around the fan 3. The robust fan control device includes a micro processing unit 10, a rotational speed sensing unit 12, a driving unit 14, a temperature sensing unit 16, and an input unit 18.

The rotation speed sensing unit 12 is electrically connected to the micro processing unit 10 and the fan 3 for sensing the rotation speed of the fan 3 and outputting the rotation speed parameter value to the micro processing unit 10. The rotational speed sensing unit 12 can be, for example, an internal timing signal of the microprocessing unit 10 to determine the number of revolutions of the fan 3 per unit time.

The driving unit 14 is electrically connected to the micro processing unit 10 and the fan 3. The drive unit 14 receives the control signal from the microprocessor unit 10 and drives the fan 3 to dissipate heat at a specific rotational speed. The driving unit 14 can adjust the rotation speed of the fan 3 by, for example, transmitting a pulse width modulation signal.

The temperature sensing unit 16 is electrically connected to the micro processing unit 10 for sensing the ambient temperature around the fan 3 and converting the measured ambient temperature into a rotational speed reference value (for example, the fan 3 rotates a certain number of turns per minute). To the micro processing unit 10. The temperature sensing unit 16 can be, for example, a thermistor or an infrared temperature sensor.

The input unit 18 is electrically connected to the micro processing unit 10, and the user can input the target parameter value according to the usage requirement, thereby adjusting the wind speed differential according to the factory setting value of each fan, so as to increase the flexibility of control. . The input unit 18 can be, for example, a keyboard or a touch panel.

In actual operation, the micro processing unit 10 may directly receive the target parameter value sent by the input unit 18, or the micro processing unit 10 may receive the temperature sensing unit 16 to input the rotational speed reference value, and then convert the rotational speed reference value into the target reference value.

Thereafter, the microprocessor unit 10 compares the fan speed value and the target parameter value outputted by the speed sensing unit 12, and increases the speed of the fan 3 in a two-stage speed increase scheme when the target parameter value and the fan speed value are different. The two-stage rotational speed increasing scheme first increases the rotational speed of the fan 3 by increasing the first rotational speed per unit time, and further increases the rotational speed of the fan 3 by increasing the second rotational speed per unit time, and the first rotational speed is greater than the second rotational speed. Thereby, not only can the time for increasing the rotation speed of the fan 3 be shortened, but also high-frequency sound waves generated when the fan 3 is increased in speed can be avoided.

The robust fan control device of the present invention can also control a plurality of fans 3 at the same time, and each fan 3 is electrically connected to the drive unit 14. In actual operation, the user may choose to input the target parameter value by using the input unit 18 for each fan 3 to perform the regulation of the fan 3 speed. However, the user can also select a part of the fan 3 to adjust the rotation speed according to the speed reference value provided by the temperature sensing unit 16, and the other part of the fan 3 adjusts the rotation speed according to the target parameter value input by the input unit 18. Of course, the user can also select all the fans 3 to adjust the rotation speed according to the same target parameter value input by the input unit 18, or make all the fans 3 adjust the rotation speed according to the rotation speed reference value provided by the temperature sensing unit 16. .

The robust fan control method of the first embodiment of the present invention will be described below with reference to the flowchart shown in FIG. The robust fan control method includes the following steps: First, the target rotational speed value is generated by the input unit 18 (step S100) and transmitted to the microprocessing unit 10.

Next, the number of instantaneous rotations of the fan 3 is sensed by the rotation speed sensing unit 12, and the fan rotation speed value can be generated by comparing the number of rotations of the fan 3 with the built-in timing signal of the micro processing unit 10 (step S104). The parameter values are passed to the microprocessing unit 10.

Thereafter, the microprocessor unit 10 compares the fan speed value with the target speed value, and when the fan speed value is different from the target speed value, causes the driving unit 14 to output the first driving signal for the first predetermined time to allow the fan speed The value increases the first speed value per unit time. The microprocessor unit 10 also causes the drive unit 14 to output a second drive signal for a second predetermined time to increase the fan speed value by a second speed value per unit time until the fan speed value is equal to the target speed value (step S108). its The first rotational speed value is greater than the second rotational speed value, the second predetermined time is later than the first predetermined time, the second predetermined time is not greater than the first predetermined time, and the first driving signal and the second driving signal are respectively pulse width modulation Change the signal. Thereby, the time for increasing the rotational speed of the fan 3 can be effectively reduced, and the high-frequency sound waves generated by the fan 3 during the increase of the rotational speed can be effectively reduced.

The robust fan control method of the second embodiment of the present invention will be described below with reference to the flowchart shown in FIG. First, the rotational speed reference value is generated by the temperature sensing unit 16 (step S102), wherein the rotational speed reference value may be, for example, an ambient temperature around the fan 3. Thereafter, the temperature sensing unit 16 transmits the rotational speed reference value to the micro processing unit 10, and is converted by the micro processing unit 10 into a target rotational speed value (step S106).

Then, the rotation speed sensing unit 12 senses the instantaneous rotation number of the fan 3, and can generate a fan rotation speed value by comparing the number of rotations of the fan 3 with the built-in timing signal of the micro processing unit 10 (step S104). The parameter values are passed to the microprocessing unit 10.

Thereafter, the microprocessor unit 10 compares the fan speed value with the target speed value, and when the fan speed value is different from the target speed value, causes the driving unit 14 to output the first driving signal for the first predetermined time to allow the fan speed The value increases the first speed value per unit time. The microprocessor unit 10 also causes the drive unit 14 to output a second drive signal for a second predetermined time to increase the fan speed value by a second speed value per unit time until the fan speed value is equal to the target speed value (step S108). The first driving speed value is greater than the second rotating speed value, the second predetermined time is later than the first predetermined time, the second predetermined time is not greater than the first predetermined time, and the first driving signal and the second driving signal are respectively pulse width adjustment Change the signal. Thereby, the time for increasing the rotational speed of the fan 3 can be effectively reduced, and the high-frequency sound waves generated by the fan 3 during the increase of the rotational speed can be effectively reduced.

Referring to FIG. 5, FIG. 5 is a diagram showing the relationship between the rotational speed and time of the robust fan speed control method according to the present invention. The solid line of FIG. 5 shows the relationship between the fan rotational speed and the time obtained by the robust fan speed control method according to the first embodiment and the second embodiment of the present invention, and the broken line shows the corresponding fan control wind law. Fan speed versus time graph.

The first line segment L1 shown by the solid line in FIG. 5 corresponds to the rotation of the fan 3 within the first predetermined time t1. The second line segment L2 corresponds to the rotational speed of the fan 3 during the second predetermined time t2. As can be seen from FIG. 3, the rotational speed of the fan 3 increases linearly during the first predetermined time t1 or the second predetermined time t2. It can be known from the slope difference of the first line segment L1 and the second line segment L2 that the first rotation speed value increased by the fan 3 per unit time during the first predetermined time t1 is higher than the second increase in the second predetermined time t2. Two speed values.

In addition, as can be seen from FIG. 5, during the first predetermined time t1, the difference in rotational speed between the fan rotational speed value and the target rotational speed value is greater than the rotational speed difference between the fan rotational speed value and the target rotational speed value during the second predetermined time t2. .

In other words, the microprocessor unit 10 can also regulate the rotational speed of the fan 3 by comparing the fan speed value with the target speed value. When the first speed difference between the fan speed value and the target speed value is greater than a second speed difference between the switching speed value and the target speed value, the microprocessor unit 10 causes the driving unit 14 to output the first driving signal to cause the fan The speed value can increase the first speed value per unit time until the fan speed value is equal to the switching speed value. When the first rotational speed difference is not greater than the second rotational speed difference, the micro processing unit 10 causes the driving unit 14 to output the second driving signal, so that the fan rotational speed value increases the second rotational speed value per unit time until the fan rotational speed value and The target speed values are equal.

Moreover, the solid line shown in FIG. 5 is compared with the broken line, and the time t3 is the time difference that the fan rotation speed is fixed at the target rotation speed value as well, and thus it can be known that the robust fan speed control method of the present invention can indeed Effectively reduce the time during which the fan speed stabilizes at the target speed value.

It should be particularly noted that the robust fan speed control device of the present invention can adjust the target rotational speed value through the temperature sensing unit 16 and the input unit 18, respectively, so that in actual operation, if the user does not input through the input unit 18 For the target speed value, the robust fan speed control device uses the speed target value measured by the temperature sensing unit 16 as the speed adjustment condition, and if the user inputs the target speed value through the input unit 18, the robust fan speed control device The target rotational speed value input by the input unit 18 is used as the rotational speed adjustment condition, and the ambient temperature of the periphery of the fan is continuously sensed by the temperature sensing unit 16. The micro-processing unit 10 further determines that the fan rotational speed value corresponding to the ambient temperature is greater than the target rotational speed value of the input unit 18 by a specific value. The rotational speed parameter value measured by the temperature sensing unit 16 resets the target rotational speed value to provide an effective antipyretic scheme.

While the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and the invention may be modified and modified in various ways without departing from the spirit and scope of the invention. The scope is subject to the definition of the scope of the patent application.

S100-S108‧‧‧Strong fan speed control steps

Claims (8)

A robust fan speed control method includes: sensing a fan speed by using a speed sensing unit, and generating a fan speed value; comparing the fan speed value with a target speed value by using a micro processing unit; When the fan speed value is different from the target speed value, the microprocessor unit causes a driving unit to output a first driving signal for a first predetermined time, so that the fan speed value increases by a first speed value per unit time. And then outputting a second driving signal for a second predetermined time to increase the fan speed value by a second speed value per unit time, the first speed value being greater than the second speed value, the second predetermined time Not greater than the first predetermined time until the fan speed value and the target speed value are equal. The method for controlling the robust fan speed according to the first item of claim 1, further comprising: the micro processing unit determining the target speed value according to a speed parameter value. The robust fan speed control method of claim 2, further comprising: sensing the speed parameter value by using a temperature sensing unit. The robust fan speed control method according to Item 2 or Item 3, wherein the speed parameter value is an ambient temperature. The robust fan speed regulation method of claim 1, further comprising: inputting the target parameter value by using an input unit. The robust fan speed control method of claim 1, wherein the speed sensing unit compares the number of revolutions of the fan with a timing signal of the microprocessor unit to generate the fan speed value. The robust fan speed control method of claim 1, wherein at the first predetermined time, the fan speed value and a first speed difference of the target speed value are greater than a switching speed value and the target speed value. A second speed difference. The robust fan speed control method of claim 7, wherein the first speed difference is not greater than the second speed difference at the second predetermined time.