The present invention relates to the technology field of cooling fan, and more particularly to a smart cooling fan system capable of adaptively modulating fan rotation speed according to CPU temperature and ambient temperature.
Computing devices, for example, desktop computer, all-in-one computer, laptop computer, industrial computer, and server, are well known becoming essential electronic devices for people and companies. Moreover, it should be known that, there are multiple cooling fans disposed in the foregoing electronic device for keeping or reducing the operating temperature of electronic chips and electronic modules disposed in a housing case of the electronic device through heat transfer, so as to prevent the electronic chips and/or the electronic modules from thermal shutdown. The electronic chips include CPU, GUP and/or digital signal processor (DSP), and the electronic modules at least include DRAM. In addition, according to conventional technologies, there is at least one temperature sensor disposed in the housing case of the electronic device for sensing an ambient temperature. As such, it is able to adaptively modulate the rotation speed of at least one cooling fan according to the ambient temperature, so as to keep or further reduce the operating temperature of electronic chips and electronic modules accommodated in the housing case.
For example, a method for optimizing fan speed control is developed for use in controlling a cooling fan system that is disposed in a housing case of a computer. The cooling fan system comprising a cooling fan, a control unit and a temperature sensor are disposed in the housing case, of which the temperature sensor is used for sensing an ambient temperature consisting of a first temperature (i.e., operating temperature) sensed from a CPU and a second temperature sensed from at least one electronic component/module (i.e., device temperature). On the other hand, the control unit, e.g., a baseboard management controller (BMC) chip, is coupled to the temperature sensor, and is provided with a temperature-duty cycle lookup table (LUT) therein. Moreover, the BMC chip is configured to find out a fan rotation speed corresponding to the ambient temperature sensed by the temperature sensor from the temperature-duty cycle LUT, thereby adaptively changing the rotation speed of the cooling fan to meet the fan rotation speed by modulating the duty cycle of a PWM signal transmitted to the cooling fan.
In real case, different electronic chips and/or electronic modules certainly have unequal operating temperature at different operation states. For example, the CPU's operating temperature rises to 80-90 degrees Celsius or even more than 90 degrees Celsius in case of the CPU utilization is 60-80%. However, the operating temperature of a normal-operation hard disk drive may be merely 40 degrees Celsius, and the operating temperature of a GPU that is executing a normal graphic computing is merely 50 degrees Celsius. In such case, because the conventional fan speed controlling method optimizes the cooling fan's rotation speed according to the ambient temperature rather than the CPU's operating temperature, the fan speed controlling method fails to specifically reduce the CPU's operating temperature by merely changing the rotation speed of a CPU cooling fan.
Accordingly, because there is room from improvement in the conventional fan speed controlling method, an improved fan speed controlling method is therefore developed and provided. According to the improved fan speed controlling method, there are two temperature sensors disposed near a CPU and a GPU, respectively, and the temperature sensors are coupled to a BMC chip. By such arrangements, the BMC chip is able to specifically change the rotation speed of a CPU cooling fan according to a CPU temperature sensed by the temperature sensor, and can also specifically change the rotation speed of a GPU cooling fan according to a GPU temperature sensed by the temperature sensor. In other words, the improved fan speed controlling method corrects the drawbacks of the above-mentioned fan speed controlling method
However, it is a pity that the proposed improved fan speed controlling method still exhibits some drawbacks in practical use. The drawbacks are summarized in following paragraphs.
(1) BMC chip is commonly used for monitoring the state of power supply and electronic modules of a host electronic device like server. When the improved fan speed controlling method is applied in the host electronic device, almost all of GPIO pins of the BMC chip are coupled to the multiple cooling fans, causing that some functionalities of the BMC chip cannot be used. Therefore, it needs to add extra one or more BMC chips in the host electronic device, such that the manufacturing cost of the host electronic device is increased.
(2) The conventional fan speed controlling method utilizes closed-loop control in combination with accessing temperature-duty cycle lookup table (LUT) to adjust the rotation speed of the cooling fan step by step. For example, adjusting the rotation speed of the cooling fan through time-by-time increasing the duty cycle of the PWM signal with an increment of 10% (i.e., 10%→20%→, . . . , →100%). However, such duty cycle modulation way fails to reduce the CPU's operating temperature immediately. In real case, the CPU's operating temperature would abruptly rises to 80-90 degrees Celsius as the CPU utilization increases to 60-80%. In such case, step-by-step modulating duty cycle obviously fails to reduce the CPU's operating temperature immediately, and also fails to prevent the CPU from thermal shutdown.
According to above descriptions, it is understood that that there are rooms for improvement in the conventional fan speed controlling method. In view of that, the inventor of the present application have made great efforts to make inventive research and eventually provided a smart cooling fan system.
The primary objective of the present invention is to disclose a smart cooling fan system, comprising: at least one first temperature sensor for sensing a first temperature form at least one main processor, at least one second temperature sensor for sensing a second temperature in a housing case that is accommodated the at least one main processor therein, at least one first cooling fan, at least one second cooling fan, and a microcontroller. According to the present invention, the microcontroller acquires an immediate rotation speed from said first cooling fan and said second cooling fan. Subsequently, after obtaining a first volumetric flow rate and a second volumetric flow rate by accessing a CFM-RPM lookup table (LUT), a first PWM LUT and a second PWM LUT, the microcontroller controls the first cooling fan to produce a first airflow having the first volumetric flow rate, and also controls the second cooling fan to produce a second airflow having the second volumetric flow rate. As a result, the operating temperature of the main processor and an ambient temperature of the housing case are therefore immediately reduced and well-controlled.
It is worth mentioning that, because the microcontroller is a CPLD of a FPGA, the microcontroller has sufficient amount of pins to be simultaneously coupled all of the multiple temperature sensors and the multiple cooling fans, and is able to control the rotation speed of each said cooling fan.
For achieving the primary objective mentioned above, the present invention provides an embodiment of the smart cooling fan system, which is disposed in a housing case of an electronic device, and comprises:
at least one first cooling fan, being disposed in the housing case, and being installed on or near at least one electronic chip; wherein said first cooling fan has a RPM signal outputting terminal and a PWM signal inputting terminal;
at least one first temperature sensor, being disposed in the housing case for sensing a first temperature of the at least one electronic chip;
at least one second cooling fan, being disposed in the housing case, and being used for exhausting a hot air produced in the housing case or feeding an external air into the housing case; wherein said second cooling fan also has a RPM signal outputting terminal and a PWM signal inputting terminal;
at least one second temperature sensor, being disposed in the housing case for sensing a second temperature of an inner space of the housing case; and
a microcontroller, having a memory and being selected from a group consisting of complex programmable logic device (CPLD) and field programmable gate array (FPGA), and being coupled to each said first temperature sensor, each said temperature sensor, the RPM signal outputting terminal and the PWM signal inputting terminal of each said first cooling fan, and the RPM signal outputting terminal and the PWM signal inputting terminal of each said second cooling fan;
wherein the memory stores a plurality of lookup tables, and the plurality of lookup tables comprising:
wherein during a normal operation of said first cooling fan and said second cooling fan, the microcontroller receiving a first immediate rotation speed of said first cooling fan and a second immediate rotation speed of said second cooling fan;
wherein after receiving a data of the first temperature sensed by said first temperature sensor, the microcontroller finding out one said first duty cycle analogue value corresponding to the first temperature value from the second lookup table, and then generating and transmitting, according to the first duty cycle analogue value, a first PWM signal with a first duty cycle to the PWM signal inputting terminal of said first cooling fan, thereby controlling said first cooling fan to produce a first airflow with a first volumetric flow rate;
wherein after receiving a data of the second temperature sensed by said second temperature sensor, the microcontroller finding out one said second duty cycle analogue value corresponding to the second temperature value from the third lookup table, and then generating and transmitting, according to the second duty cycle analogue value, a second PWM signal a with a second duty cycle to the PWM signal inputting terminal of said second cooling fan, thereby controlling said second cooling fan to produce a second airflow with a second volumetric flow rate.
In one embodiment, said electronic chip is selected from a group consisting of CPU, GPU, digital signal processor (DSP), and application processor.
In one practicable embodiment, one said electronic chip is a CPU, and another one said electronic chip is GPU, and two said first temperature sensors includes a first thermal diode coupled to the CPU and a second thermal diode coupled to the GPU. Moreover, the microcontroller communicates with the CPU and the GPU through PECI protocol, so as to receive a data of a CPU temperature sensed by the first thermal diode from the CPU as well as receive a data of a GPU temperature sensed by the second thermal diode from the GPU.
In another one practicable embodiment, one said electronic chip is a CPU, and another one said electronic chip is GPU, and two said first temperature sensors includes a first thermal diode integrated in the CPU and a second thermal diode integrated in the GPU. Moreover, the microcontroller communicates with the CPU and the GPU through PECI protocol, so as to receive a data of a CPU temperature sensed by the first thermal diode from the CPU as well as receive a data of a GPU temperature sensed by the second thermal diode from the GPU.
In one embodiment, a readout chip is coupled the microcontroller, the RPM signal outputting terminal and the PWM signal inputting terminal of each said first cooling fan, and the RPM signal outputting terminal and the PWM signal inputting terminal of each said second cooling fan, such that the microcontroller receives the first immediate rotation speed of said first cooling fan and the second immediate rotation speed of said second cooling fan through the readout chip.
In a practicable embodiment, the smart cooling fan system of the present invention further comprises:
at least one third cooling fan, being disposed in the housing case, and being installed on or near at least one electronic module; wherein said third cooling fan also has a RPM signal outputting terminal and a PWM signal inputting terminal;
at least one third temperature sensor, being disposed in the housing case for sensing a third temperature of the at least one electronic module;
wherein the plurality of lookup tables further comprises a fourth lookup table, recording N number of third duty cycle analogue values and N number of third temperature values corresponding to the N number of third duty cycle analogue values, N being an positive integer;
wherein during a normal operation of said third cooling fan, the microcontroller receiving a third immediate rotation speed of said third cooling fan;
wherein after receiving a data of the third temperature sensed by said third temperature sensor, the microcontroller finding out one said third duty cycle analogue value corresponding to the third temperature value from the fourth lookup table, and then generating and transmitting, according to the third duty cycle analogue value, a third PWM signal with a third duty cycle to the PWM signal inputting terminal of said third cooling fan, thereby controlling said third cooling fan to produce a third airflow with a third volumetric flow rate.
In one embodiment, the electronic module is selected from a group consisting of DRAM, hard disk drive and LED lighting device, and said electronic chip is selected from a group consisting of CPU, GPU, digital signal processor (DSP), and application processor.
In a practicable embodiment, the smart cooling fan system of the present invention further comprises: a management unit coupled to a BIOS chip of the electronic device, wherein the management unit is used for communicating with an external electronic device, such that the external electronic device writes the at least one first lookup table, the second lookup table, the third lookup table, and the fourth lookup table into a storage space of the BIOS chip.
The invention as well as a preferred mode of use and advantages thereof will be best understood by referring to the following detailed description of an illustrative embodiment in conjunction with the accompanying drawings, wherein:
To more clearly describe a smart cooling fan system, embodiments of the present invention will be described in detail with reference to the attached drawings hereinafter.
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Herein, it needs to further explain that, CFM stands for cubic feet per minute (it is also referred to as airflow). Put simply, CFM is how much air a fan moves. The measurement is taken when the cooling fan is on a specified speed and uses both the volume of air and the rate at which it moves. For example, a commercial CPU cooling fan (i.e., said first cooling fan FA1) has the maximum airflow capacity of 30-40 CFM, a commercial computer case fan (i.e., said second cooling fan FA2) has the maximum airflow capacity of 60-120 CFM, and a commercial DRAM cooling fan (i.e., said third cooling fan FA3) has the maximum airflow capacity of 20-25 CFM. Therefore, after measuring CFM-RPM curves of each said first cooling fan FA1, each said second cooling fan FA2 and each said cooling fan FA3, duty cycle-CFM curves of each said first cooling fan FA1, each said second cooling fan FA2 and each said cooling fan FA3, duty cycle-CFM are simultaneously obtained. Subsequently, a duty cycle-duty cycle analogue value lookup table (LUT) shown as follows can be generated according to one duty cycle-CFM curve.
After obtaining the duty cycle-duty cycle analogue value LUT like above table (1), a duty cycle analogue value-temperature LUT can be further generated as follows.
It needs to further explain that, number of the switching level of the duty cycle of a PWM signal is not limited to 5 like the above-presented table (2) shows. In a practicable embodiment, the number of the switching level of the duty cycle can be set to 5, 7, or 10. Therefore, after setting the number of the switching level of the duty cycle, it can further decide a quiet and energy-saving region and a high-efficiency heat dissipation region on
In summary, the memory 131 of the microcontroller 13 stores a first LUT (i.e., CFM-RPM LUT), a second LUT (i.e., duty cycle analogue values-temperature LUT), a third LUT (i.e., duty cycle analogue values-temperature LUT), and, a fourth LUT (i.e., duty cycle analogue values-temperature LUT). By such arrangements, during a normal operation of said first cooling fan FA1, said second cooling fan FA2 and said third cooling fan FA3, the microcontroller 13 receives a first immediate rotation speed of said first cooling fan FA1, a second immediate rotation speed of said second cooling fan FA2 and a third immediate rotation speed of said third cooling fan FA3 from the readout chip 11. Subsequently, after receiving a data of the first temperature sensed by said first temperature sensor T1, the microcontroller 13 find out one said first duty cycle analogue value corresponding to the first temperature value from the second LUT (e.g., table (2)), and then generates and transmits, according to the first duty cycle analogue value, a first PWM signal with a first duty cycle to the PWM signal inputting terminal of said first cooling fan FA1, thereby controlling said first cooling fan FA1 to produce a first airflow with a first volumetric flow rate (e.g. 20 CFM).
Moreover, after receiving a data of the second temperature sensed by said second temperature sensor T2, the microcontroller 13 finds out one said second duty cycle analogue value corresponding to the second temperature value from the third LUT, and then generates and transmits, according to the second duty cycle analogue value, a second PWM signal a with a second duty cycle to the PWM signal inputting terminal of said second cooling fan FA2, thereby controlling said second cooling fan FA2 to produce a second airflow with a second volumetric flow rate (e.g., 70 CFM). In addition, after receiving a data of the third temperature sensed by said third temperature sensor T3, the microcontroller 13 finds out one said third duty cycle analogue value corresponding to the third temperature value from the fourth LUT, and then generates and transmits, according to the third duty cycle analogue value, a third PWM signal with a third duty cycle to the PWM signal inputting terminal of said third cooling fan FA3, thereby controlling said third cooling fan FA3 to produce a third airflow with a third volumetric flow rate (e.g., 20 CFM).
As described in more detail below, the second LUT (e.g., table (2)) is set for being accessed by the microcontroller 13 so as to control the CFM value and the RPM value of the first cooling fan FA1, and the second LUT records L number of first duty cycle analogue values (e.g. 0˜255) and L number of first temperature values corresponding to the L number of first duty cycle analogue values. Moreover, the third LUT is set for being accessed by the microcontroller 13 so as to control the CFM value and the RPM value of the second cooling fan FA2, and the third LUT records M number of first duty cycle analogue values (e.g. 0˜255) and M number of first temperature values corresponding to the M number of first duty cycle analogue values. On the other hand, the fourth LUT is set for being accessed by the microcontroller 13 so as to control the CFM value and the RPM value of the third cooling fan FA3, and the fourth LUT records N number of first duty cycle analogue values (e.g. 0˜255) and N number of first temperature values corresponding to the N number of first duty cycle analogue.
As
In other words, the microcontroller 13 acquires an immediate rotation speed from said first cooling fan FA1, said second cooling fan FA2 and said cooling fan FA3. Subsequently, after obtaining a first volumetric flow rate (i.e., CFM value for FA1), a second volumetric flow rate (i.e., CFM value for FA2) and a third volumetric flow rate (i.e., CFM value for FA3) by accessing a CFM-RPM lookup table (LUT), a first LUT, a second LUT and a third LUT, the microcontroller 13 controls the first cooling fan FA1 to produce a first airflow having the first volumetric flow rate, controls the second cooling fan FA2 to produce a second airflow having the second volumetric flow rate, and also controls the third cooling fan FA3 to produce a third airflow having the third volumetric flow rate. As a result, the operating temperature of the at least one electronic chip (i.e., CPU or GPU) 22, an ambient temperature of the housing case 21 and at least one electronic module (i.e., DRAM, HD, LED) 23 are therefore immediately reduced and well-controlled. For example, when the operating temperature of a CPU (i.e., one said electronic chip 22) abruptly rises to 80-90 degrees Celsius, the microcontroller 13 controls the three cooling fans (FA1, FA2, FA3) to immediately be operated in the high-efficiency cooling region, so as to reduce the operating temperature of the CPU in a short time period, thereby preventing the CPU from thermal shutdown. On the contrary, in case of the operating temperature of the CPU is decreasing with the CPU utilization, the microcontroller 13 controls the three cooling fans (FA1, FA2, FA3) to be immediately operated in the quiet and energy-saving region, so as to reduce noise of the three cooling fans (FA1, FA2, FA3) in a short time period.
In a real application case, the at least one first lookup table, the second lookup table, the third lookup table, and the fourth lookup table are stored in a storage space of the BIOS chip 24. Therefore, because a register is adopted as the memory 131 of the microcontroller 13, such that the at least one first lookup table, the second lookup table, the third lookup table, and the fourth lookup table are loaded into the memory 131 from the storage space of the BIOS chip 24 after the microcontroller 13 is awakened. It is worth explaining that, the microcontroller 13 selects and loads corresponding LUTs from the BIOS chip 24 into the register (i.e., memory 131) according to the model of the electronic chip 22 and the electronic module 23.
As described in more detail below, commercial CPU (GPU) is commonly coupled with a thermal diode, wherein this thermal diode is used for monitoring the operating temperature of the CPU (GPU). In such case, as
On the other hand, high-level CPU (GPU) is commonly integrated with a thermal diode therein. In such case, as
It is worth further explaining that, there is no need to calibrate the thermal diode (i.e., the first temperature sensor) integrated in a CPU (GPU) before utilizing the thermal diode to sense the operating temperature of the CPU (GPU). On the contrary, calibration is needed for the second temperature sensor T2 for monitoring the inner ambient temperature and the third temperature sensor T3 for monitoring the operating temperature of the electronic module 23. As described in more detail below, thermal resistor, having a base temperature (or called reference temperature), is adopted as the second temperature sensor T2 and the first temperature sensor, and it is necessary to calibrate the base temperature before utilizing the thermal resistor because the base temperature may vary with environment temperature.
With reference to
In a practicable embodiment, the management unit 221 can be a platform security processor (PSP) proposed by AMD or an Intel management engine (IME), wherein the PSP and the IME are both remote controllable. In other words, the external electronic device is allowed to write the at least one first LUT, the second LUT, the third LUT, and the fourth LUT into the storage space of the BIOS chip 24 through the management unit 221. In addition, the external electronic device is also allowed to write a fan rotation speed controlling command into the storage space of the BIOS chip 24 through the management unit 221, so as to make the microcontroller 13 adjust the first volumetric flow rate of the first cooling fan FA1, the second volumetric flow rate of the second cooling fan FA2, and/or the third volumetric flow rate of the third cooling fan FA3 according to the fan rotation speed controlling command.
Therefore, through the above descriptions, all embodiments of the smart cooling fan system according to the present invention have been introduced completely and clearly. Moreover, the above description is made on embodiments of the present invention. However, the embodiments are not intended to limit the scope of the present invention, and all equivalent implementations or alterations within the spirit of the present invention still fall within the scope of the present invention.
Number | Date | Country | Kind |
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110131921 | Aug 2021 | TW | national |