CN114876839B - Fan system and fan driving method - Google Patents
Fan system and fan driving method Download PDFInfo
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- CN114876839B CN114876839B CN202110163483.7A CN202110163483A CN114876839B CN 114876839 B CN114876839 B CN 114876839B CN 202110163483 A CN202110163483 A CN 202110163483A CN 114876839 B CN114876839 B CN 114876839B
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- 238000000034 method Methods 0.000 title claims abstract description 32
- 230000003247 decreasing effect Effects 0.000 claims abstract description 23
- 230000007423 decrease Effects 0.000 claims description 9
- 238000011084 recovery Methods 0.000 claims description 7
- 238000001514 detection method Methods 0.000 claims description 2
- 238000012423 maintenance Methods 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 11
- 238000013459 approach Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 1
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D27/00—Control, e.g. regulation, of pumps, pumping installations or pumping systems specially adapted for elastic fluids
- F04D27/004—Control, e.g. regulation, of pumps, pumping installations or pumping systems specially adapted for elastic fluids by varying driving speed
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D25/00—Pumping installations or systems
- F04D25/02—Units comprising pumps and their driving means
- F04D25/08—Units comprising pumps and their driving means the working fluid being air, e.g. for ventilation
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D25/00—Pumping installations or systems
- F04D25/16—Combinations of two or more pumps ; Producing two or more separate gas flows
- F04D25/166—Combinations of two or more pumps ; Producing two or more separate gas flows using fans
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D27/00—Control, e.g. regulation, of pumps, pumping installations or pumping systems specially adapted for elastic fluids
- F04D27/001—Testing thereof; Determination or simulation of flow characteristics; Stall or surge detection, e.g. condition monitoring
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F05D2270/00—Control
- F05D2270/30—Control parameters, e.g. input parameters
- F05D2270/304—Spool rotational speed
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D10/00—Energy efficient computing, e.g. low power processors, power management or thermal management
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Control Of Positive-Displacement Air Blowers (AREA)
Abstract
The present disclosure relates to a fan system and a fan driving method. The fan system comprises a first fan and a second fan which are respectively used for running according to a first driving signal and a second driving signal and generating a first rotating speed signal and a second rotating speed signal. The first rotational speed signal has a first phase and the second rotational speed signal has a second phase. The second fan is electrically connected to the first fan to receive the first rotation speed signal and obtain a detected phase difference between the first phase and the second phase. The second fan is also used for selectively increasing or decreasing the duty ratio of the second driving signal according to the detected phase difference, so that the second phase is adjusted to maintain the preset phase difference with the first phase, and the unstable power supply caused by the phase overlapping is avoided.
Description
Technical Field
The present disclosure relates to a fan system and a fan driving method, and more particularly, to a fan system and a fan driving method for controlling a plurality of fans to maintain the same rotation speed.
Background
With the development of technology, the operating frequency of various electronic devices is increased, but the increase of the operating frequency causes the internal temperature of the electronic device to be relatively increased when the electronic device is operated, so that the fan is essential for maintaining the operation of the electronic device in order to prevent the high temperature from affecting the operation of the electronic device, even damaging the electronic device.
The fan system often includes a plurality of fans and is controlled at the same rotation speed. However, when the fan is actually running, the rotation speed of the fan often floats due to various variables or different operation requirements, and may need to be adjusted for the power supply requirements.
Disclosure of Invention
The present disclosure relates to a fan driving method, comprising the following steps: driving the first fan according to the first driving signal and driving the second fan according to the second driving signal; obtaining a first rotating speed signal from a first fan and a second rotating speed signal from a second fan, wherein the first rotating speed signal has a first phase and the second rotating speed signal has a second phase; comparing the difference between the second phase and the first phase when the frequency of the first rotational speed signal is determined to be stable, so as to obtain a detected phase difference; and selectively increasing or decreasing the duty ratio of the second driving signal according to the detected phase difference to adjust the second phase to maintain the preset phase difference with the first phase.
In an embodiment, the method of selectively increasing or decreasing the duty cycle of the second driving signal further comprises: in the first period, according to the detected phase difference, the duty ratio of the second driving signal is increased or decreased from the first ratio to the second ratio; and in the second period, restoring the duty ratio of the second driving signal to the first ratio.
In an embodiment, the method of selectively increasing or decreasing the duty cycle of the second driving signal further comprises: during the adjustment period in the first period, the duty ratio of the second driving signal is increased or decreased from the first ratio to the second ratio according to the detected phase difference; and recovering the duty ratio of the second driving signal to the first ratio during the recovery in the first period.
In an embodiment, the duty cycle of the second drive signal is progressively restored to the first ratio during the restoration period.
In one embodiment, the fan driving method further comprises: judging whether the difference between the detected phase difference and the preset phase difference is within 5%.
In an embodiment, the first rotation speed signal has a first frequency, the second rotation speed signal has a second frequency, and the fan driving method further includes: judging whether the first frequency is stable; comparing the difference between the second frequency and the first frequency when the first frequency is unstable to obtain a detected frequency difference; and selectively increasing or decreasing the duty ratio of the second driving signal according to the detected frequency difference, so that the second frequency is changed towards the first frequency.
In one embodiment, the second fan is configured to receive the first rotational speed signal from the first fan and determine whether the first frequency is stable.
In one embodiment, the fan driving method further comprises: recording a plurality of signal phases of the first rotating speed signal at a plurality of starting time points of a plurality of periods of the second rotating speed signal respectively; and comparing the signal phases of the first rotational speed signal.
The disclosure also relates to a fan system including a first fan and a second fan. The first fan is used for operating according to a first driving signal to generate a first rotating speed signal, wherein the first rotating speed signal has a first phase. The second fan is electrically connected to the first fan and is operated according to the second driving signal to generate a second rotation speed signal. The second rotating speed signal has a second phase, and the second fan is used for receiving the first rotating speed signal so as to obtain a detection phase difference between the second phase and the first phase. The second fan is also used for selectively increasing or decreasing the duty ratio of the second driving signal according to the detected phase difference, so that the second phase is adjusted to maintain the preset phase difference with the first phase.
In an embodiment, in the first period, the second fan increases or decreases the duty ratio of the second driving signal from the first ratio to the second ratio according to the detected phase difference; in the second period, the second fan restores the duty ratio of the second driving signal to the first ratio.
In an embodiment, during the adjustment in the first period, the second fan increases or decreases the duty ratio of the second driving signal from the first ratio to the second ratio according to the detected phase difference; during the recovery period in the first period, the second fan recovers the duty ratio of the second driving signal to the first ratio.
In an embodiment, during the recovery period, the second fan progressively recovers the duty cycle of the second driving signal to the first ratio.
In one embodiment, the second fan is further configured to determine whether the difference between the detected phase difference and the predetermined phase difference is within 5%.
In one embodiment, when the first frequency is unstable, the second fan compares the difference between the second frequency and the first frequency to obtain a detected frequency difference; the second fan is also used for selectively increasing or decreasing the duty ratio of the second driving signal according to the detected frequency difference, so that the second frequency changes towards the first frequency.
In an embodiment, at a plurality of starting time points of a plurality of periods of the second rotation speed signal, the second fan is used for respectively recording a plurality of signal phases of the first rotation speed signal, and comparing the signal phases of the first rotation speed signal.
The disclosure also relates to a fan driving method, comprising the following steps: driving the first fan according to the first driving signal and driving the second fan according to the second driving signal; obtaining a first rotating speed signal from a first fan and a second rotating speed signal from a second fan, wherein the first rotating speed signal has a first frequency and the second rotating speed signal has a second frequency; comparing the difference between the second frequency and the first frequency to obtain a detected frequency difference when the frequency of the first rotation speed signal is unstable; and selectively increasing or decreasing the duty ratio of the second driving signal according to the detected frequency difference, so that the second frequency is changed towards the first frequency.
In an embodiment, the first rotation speed signal has a first phase, the second rotation speed signal has a second phase, and the fan driving method further includes: comparing the difference between the second phase and the first phase when the frequency of the first rotational speed signal is determined to be stable, so as to obtain a detected phase difference; and selectively increasing or decreasing the duty ratio of the second driving signal according to the detected phase difference to adjust the second phase to maintain the preset phase difference with the first phase.
In an embodiment, the method of selectively increasing or decreasing the duty cycle of the second driving signal further comprises: in the first period, according to the detected phase difference, the duty ratio of the second driving signal is increased or decreased from the first ratio to the second ratio; and in the second period, restoring the duty ratio of the second driving signal to the first ratio.
In an embodiment, the method of selectively increasing or decreasing the duty cycle of the second driving signal further comprises: during the adjustment period in the first period, the duty ratio of the second driving signal is increased or decreased from the first ratio to the second ratio according to the detected phase difference; and recovering the duty ratio of the second driving signal to the first ratio during the recovery in the first period.
In an embodiment, the duty cycle of the second drive signal is progressively restored to the first ratio during the restoration period.
Therefore, by comparing the phase differences among the rotating speed signals and adjusting the duty ratio of the driving signals according to the detected phase differences, the phases of the rotating speed signals can be staggered, and the problem of unstable supply current caused by phase overlapping is avoided.
Drawings
FIG. 1A is a schematic diagram of a fan system according to some embodiments of the present disclosure;
FIG. 1B is a schematic diagram of a fan system according to some embodiments of the present disclosure;
FIG. 2A is a waveform diagram of a rotational speed signal according to some embodiments of the present disclosure;
FIG. 2B is a waveform diagram of a rotational speed signal according to some embodiments of the present disclosure;
FIG. 2C is a waveform diagram of a rotational speed signal according to some embodiments of the present disclosure;
FIG. 3 is a flow chart of a fan driving method according to some embodiments of the present disclosure;
FIG. 4A is a schematic diagram of a current signal according to some embodiments of the present disclosure;
fig. 4B is a schematic diagram of a current signal according to some embodiments of the present disclosure.
[ Symbolic description ]
100 Fan System
110 First fan
111 First controller
112 First motor
113 First detector
114 First fan blade
120 Second fan
121 Second controller
122, Second motor
123 Second detector
124 Second fan blade
Vd1 first rotational speed signal
Vd2 second rotational speed signal
P1-P4 period
T1 adjustment period
T2 during recovery
Duty1: duty cycle
Duty2: duty cycle
S301-S308 step
Detailed Description
Various embodiments of the invention are disclosed in the accompanying drawings, and for purposes of explanation, numerous practical details are set forth in the following description. However, it should be understood that these practical details are not to be taken as limiting the invention. That is, in some embodiments of the invention, these practical details are unnecessary. Furthermore, for the purpose of simplifying the drawings, some known and conventional structures and elements are shown in the drawings in a simplified schematic manner.
Herein, when an element is referred to as being "connected" or "coupled," it can be referred to as being "electrically connected" or "electrically coupled. "connected" or "coupled" may also mean that two or more elements co-operate or interact with each other. Furthermore, although the terms "first," "second," …, etc. may be used herein to describe various elements, this term is merely intended to distinguish between elements or operations that are described in the same technical term. Unless the context clearly indicates otherwise, the terms are not specifically intended or implied to be order or cis-ient nor intended to limit the invention.
Fig. 1A and 1B are schematic diagrams of a fan system 100 according to some embodiments of the present disclosure. The fan system 100 at least includes a first fan 110 and a second fan 120. The first fan 110 is operated according to the first driving signal to generate a first rotation speed signal. The second fan 120 is operated according to the second driving signal to generate a second rotation speed signal.
As shown in fig. 1A and 1B, the first fan 110 includes a first controller 111, a first motor 112, a first detector 113, and a first fan blade 114. The second fan 120 includes a second controller 121, a second motor 122, a second detector 123, and a second fan blade 124. The first fan 110 and the second fan 120 are operated according to the power of the power supply VDD, and the controller 111/121 adjusts the power provided to the motor 112/122 according to the driving signal, so as to drive the fan blades 114/124 to rotate. The driving signal may be generated by the controller 111/121 or may be received from an external source (e.g., motherboard).
In some embodiments, the first/second drive signals are in the form of pulse width modulation (Pulse Width Modulation, PWM) to adjust the time the motor 112/122 is running by varying the duty cycle of the power supply, thereby varying the rotational speed of the fan. For example, when the duty ratio of the first/second driving signal is 60%, the rotation speed of the fan is 60% of the maximum rotation speed.
The rotation speed signals Vd1/Vd2 are used to reflect the current rotation speed of the fan 110/120. In one embodiment, the detectors 113/123 in the first fan 110 and the second fan 120 are used to detect the rotor position of the fan blades 114/124 or the motor 112/122, so as to generate a rotation speed signal. The waveform of the rotation speed signal is a square wave (as shown in fig. 2A, which will be described in detail in the following paragraphs). The first rotation speed signal Vd1 has a first phase and a first frequency. The second rotation speed signal Vd2 has a second phase and a second frequency. Wherein the frequency (period) of the rotation speed signals Vd1/Vd2 represents the rotation speed. In other embodiments, the current position of the fan blades or motor rotor can be calculated through current flow confide a stratagem to without installing a detector in the fan 110/120. Since the generation manner of the rotation speed signal can be understood by those skilled in the art, the description thereof is omitted herein.
In the present embodiment, the second fan 120 refers to the rotation speed of the first fan 110, and adjusts the rotation speed of the second fan 120 to make the rotation speed of the second fan be consistent with that of the first fan 110, but the phase of the second rotation speed signal Vd2 needs to be staggered (e.g. 90 degrees apart) from the first rotation speed signal Vd1, so as to avoid the problem of unstable current of the power supply.
Specifically, the second fan 120 is electrically connected to the first fan 110 to receive the first rotation speed signal Vd1 recorded by the first detector 113. After receiving the first rotation speed signal Vd1, the second controller 121 of the second fan 120 compares the difference between the first phase of the first rotation speed signal Vd1 and the second phase of the second rotation speed signal Vd2 to obtain a detected phase difference.
For example, if the first phase of the first rotation speed signal Vd1 is separated by about 20 degrees and the predetermined phase difference is 90 degrees, the second controller 121 of the second fan 120 increases the duty ratio of the second driving signal, and the second phase of the second rotation speed signal Vd2 is shifted forward, so that the phase difference between the second phase and the first phase increases, and the predetermined phase difference (i.e., the phase difference is changed from 20 degrees to 90 degrees) can be satisfied.
On the other hand, if the first phase of the first rotation speed signal Vd1 leads the second phase of the second rotation speed signal Vd2 by about 20 degrees, the second controller 121 of the second fan 120 may decrease the duty ratio of the second driving signal. At this time, the second phase of the second rotation speed signal Vd2 will shift backward, so that the phase difference between the second phase and the first phase will increase, and the predetermined phase difference is met. In other words, the second fan 120 selectively increases or decreases the duty cycle of the second driving signal according to the detected phase difference, so that the second phase is adjusted to maintain a predetermined phase difference (e.g. 90 degrees) with the first phase.
In some embodiments, the fan system 100 may further include a third fan, a fourth fan, and so on in addition to the first fan 110 and the second fan 120. The other fans are electrically connected to the first fan 110 in the control manner of the second fan 120, so as to receive the first rotation speed signal, and control the rotation speed corresponding to the first fan 110 according to the first rotation speed signal and the detected phase difference, but the phases of the rotation speed signals are mutually staggered (for example, the phase of the first fan leads the phase of the second fan by 45 degrees, and the phase of the first fan leads the phase of the third fan by 90 degrees). Therefore, the problem of unstable power supply caused by overlarge instantaneous current demand due to the same phase of a plurality of fans can be avoided.
In some embodiments, to enable all fans to maintain the same rotational speed, the fan system 100 may also adjust the rotational speed or the phase of the signal in different ways according to different situations. Fig. 2A is a waveform diagram of a rotational speed signal according to some embodiments of the present disclosure, in an embodiment, the first rotational speed signal Vd1 and the second rotational speed signal Vd2 have distinct phase differences, and the frequencies and the periods of the two signals are different. As shown, the frequency of the first rotational speed signal Vd1 is significantly greater than the frequency of the second rotational speed signal Vd2, representing a great rotational speed difference therebetween. At this time, the second fan 120 will first boost the duty ratio of the second driving signal, so that the frequency of the second rotation speed signal Vd2 can be increased to the frequency of the first rotation speed signal Vd1 (i.e., the rotation speeds are equal).
In other embodiments, the second fan 120 determines whether the first rotation speed signal Vd1 is stable? If the frequency of the first rotational speed signal Vd1 is continuously changed over a period of time, it means that the speed of the first fan 110 has not stabilized (e.g., is accelerating or decelerating). When the frequency of the first rotation speed signal is unstable, the second fan 120 also adjusts the duty ratio of the second driving signal in the above manner, so that the rotation speed of the second fan 120 approaches the rotation speed of the first fan 110.
In summary, the second fan 120 compares the difference between the first frequency of the first rotation speed signal Vd1 and the second frequency of the second rotation speed signal to obtain a detected frequency difference (or obtain a difference in cycle length). Then, by detecting the frequency difference (e.g., the second frequency is lower than the first frequency), the second fan 120 selectively increases or decreases the duty ratio of the second driving signal, so that the second frequency changes towards the first frequency, and the first fan 110 and the second fan 120 have the same rotation speed.
Referring to fig. 2B, in another embodiment, when the frequency of the first rotation speed signal Vd1 is stable, the second fan 120 determines whether the detected phase difference is within a set range (e.g., less than 10%). If the phase difference is much larger than the preset phase difference (for example, the phase difference is 20% but the preset phase difference is 8%), the second fan 120 adjusts the duty ratio of the second driving signal according to the detected phase difference, so that the rotation speed of the second fan 120 approaches the rotation speed of the first fan 110.
In contrast, if the phase difference is far less than or equal to the preset phase difference, the second fan 120 further adjusts the phase of the second rotation speed signal Vd2 (corresponding to the phase of the second driving signal), so that the preset phase difference can be maintained between the first phase and the second phase. In some embodiments, the second fan 120 temporarily adjusts the duty ratio of the second driving signal, so that the phases of the second driving signal and the second rotation speed signal are changed (e.g. shifted forward or backward), and the phases of the first rotation speed signal and the second rotation speed signal can be maintained at the predetermined phase difference.
Specifically, if the detected phase difference detected by the second fan 120 is "+20 degrees", it means that the second phase of the second rotation speed signal Vd2 leads the first phase of the first rotation speed signal Vd1 by 20 degrees. At this time, in order to adjust the second phase of the second rotation speed signal Vd2, but not change the average rotation speed of the second fan 120, the second fan 120 will first briefly adjust the duty ratio of the second driving signal, and then restore the original duty ratio. For example, as shown in fig. 2B, the second fan 120 increases the duty ratio of the second driving signal from the first ratio (e.g., 60%) to the second ratio (e.g., 80%) during the first period P1. After the first period P1, the second fan 120 restores the duty ratio of the second driving signal to the original first ratio (e.g., 60%) when entering the second period P2. Accordingly, the phase difference between the second rotation speed signal Vd2 and the first rotation speed signal Vd1 will be increased, but the speed of the second fan 120 will not be changed.
In addition, after the first period P1, the second fan 120 will determine the detected phase difference between the first phase and the second phase again, and is in accordance with the predetermined phase difference? Or detecting if the phase difference is within a set range (e.g., 5%, 3%, or 2%)? The second fan 120 can detect the signal period lengths of the first rotation speed signal Vd1 and the second rotation speed signal Vd2, respectively, so as to perform the above-mentioned determination.
In other embodiments, the second controller 121 of the second fan 120 may record the signal phase of the first rotational speed signal Vd1 at the start time point of each period of the second rotational speed signal Vd2, and compare the signal phases recorded each time to determine "whether the first rotational speed signal Vd1 is stable? Or determining the detected phase difference between the first rotation speed signal Vd1 and the second rotation speed signal Vd 2. For example, as shown in fig. 2B, if the second fan 120 does not adjust the second driving signal, and the signal phase recorded to the first rotation speed signal Vd1 is "320 degrees, 240 degrees, 180 degrees, 140 degrees" at each start time point of the four periods P1 to P4 of the second rotation speed signal Vd2, respectively, which indicates that the frequency of the first rotation speed signal Vd1 is unstable.
On the other hand, after the second fan 120 adjusts the second driving signal, when the start time points of the four periods P1 to P4 of the second rotation speed signal Vd2 are each time, the signal phase recorded in the first rotation speed signal Vd1 is "320 degrees, 240 degrees, 180 degrees, 140 degrees", which represents that the second phase is gradually increased. If the preset phase difference is "90 degrees", when the start time point of one period of the second rotation speed signal Vd2 is at the start time point, if the signal phase of the first rotation speed signal Vd1 is "90 degrees", the adjustment of the signal is completed.
Referring to FIG. 2C, in one embodiment, if the phase difference (e.g., 83 degrees) between the first phase and the second phase is very close to the predetermined phase difference (e.g., 90 degrees). At this time, the second phase of the second rotation speed signal Vd2 may be selectively fine-tuned in a more accurate manner. As shown in fig. 2C, wherein the square "width" of the "duty1, duty2" represents the duty "size" of the second driving signal corresponding to the second rotation speed signal Vd2 at the same timing (e.g., the time of driving the motor in each cycle). That is, in the embodiment shown in fig. 2C, the duty ratio duty1 is greater than the duty ratio duty2, and the second phase can be advanced accordingly.
Specifically, during the adjustment period T1 of the first period, the second fan 120 increases the duty ratio of the second driving signal from the first ratio (i.e., duty1, for example, 60%) to the second ratio (i.e., duty2, for example, 80%) according to the detected phase difference. While the second fan 120 restores the duty ratio of the second driving signal from the second ratio (i.e., duty2, for example, 80%) to the first ratio (i.e., duty1, for example, 60%) during the restoration period T2 in the first period. In other words, the second fan 120 instantaneously changes the duty ratio of the second driving signal in a period, and then restores the original duty ratio, thereby adjusting the second phase. The length of the adjustment period T1 (i.e., the proportion of the first period) may be changed according to the detected phase difference. For example: the greater the detected phase difference, the longer the length of the adjustment period T1.
In other embodiments, the duty cycle of the second fan 120 is gradually changed, that is, the duty cycle of the second driving signal is changed from the first ratio (e.g., 60%) to the second ratio (e.g., 80%) in a linear change manner, and then is restored to the first ratio in a linear change manner.
In some embodiments, the second fan 120 determines whether the detected phase difference (i.e., the actual difference between the second phase and the first phase) and the predetermined phase difference (i.e., the ideal difference between the second phase and the first phase) are within a predetermined range (e.g., 5%, 3%, or 2%? If so, the detected phase difference is very close to the predetermined phase difference, and the second driving signal is fine-tuned in the manner shown in fig. 2C. Otherwise, the second phase of the second driving signal is adjusted according to the method of fig. 2B.
FIG. 3 is a flow chart of a fan driving method according to some embodiments of the present disclosure. In step S301, the second controller 121 of the second fan 120 receives the first rotation speed signal Vd1 from the first detector 113. In step S302, the second controller 121 determines whether the frequency (or period length) of the first rotation speed signal Vd1 is stable. The second controller 121 can detect the period length of the first rotation speed signal Vd1 in a plurality of periods to determine whether the signal is stable.
In step S303, if the frequency (or the period length) of the first rotation speed signal Vd1 is unstable, the second controller 121 further compares the first frequency of the first rotation speed signal Vd1 with the second frequency of the second rotation speed signal Vd2 to obtain the detected frequency difference. In step S304, the second controller 121 adjusts the duty ratio of the second driving signal according to the detected frequency difference. For example, if the detected frequency difference is "the first frequency is greater than 200Hz" the second frequency, the second controller 121 will increase the duty cycle of the second driving signal, so that the second frequency is increased accordingly.
In step 305, if it is determined that the frequency (or the period length) of the first rotation speed signal Vd1 is stable, the second controller 121 compares the difference between the first phase and the second phase to obtain the detected phase difference. In step S306, the second controller 121 further determines whether the detected phase difference is within a set range (e.g., 90 degrees).
In step S307, if the detected phase difference and the preset phase difference are not within the set range, the second controller 121 increases or decreases the duty ratio of the second driving signal from the first ratio to the second ratio in the first period according to the detected phase difference. Next, when the second period is entered, the second control 121 restores the duty ratio of the second driving signal to the first ratio.
In step S308, if the detected phase difference and the preset phase difference are not within the set range, the second control 121 increases or decreases the duty ratio of the second driving signal from the first ratio to the second ratio according to the detected phase difference during the adjustment period T1 in the first period. Next, the second control 121 restores the duty ratio of the second driving signal to the first ratio in the restoration period T2 in the first period.
The steps S301 to S308 may be repeatedly or cyclically executed. In other words, during the operation of the fan system 100, the second controller 121 can repeatedly execute the determining operations of steps S302 and S306 to make corresponding adjustments according to the current rotation speed conditions of the first fan 110 and the second fan 120.
Accordingly, the second driving signal can be adjusted according to different conditions by the fan driving method, so that the rotation speed of the second fan 120 can be kept consistent with that of the first fan 110, and the signal phase of the second fan 120 is kept different from the preset phase of the first fan 110, so as to avoid the problem of unstable current caused by overlapping the phases of the current signals of the fans.
Fig. 4A is a waveform diagram of the current outputted by the power supply VDD when the fan system 100 has not adjusted the rotation speed according to the driving method. Fig. 4B is a waveform diagram of the current outputted from the power supply VDD when the fan system 100 adjusts the rotation speed according to the driving method. Comparing the current waveforms shows that the current will be more stable after shifting the phase of the rotational speed signal.
The elements, method steps or technical features of the foregoing embodiments may be combined with each other, and are not limited to the text description order or the order in which the drawings are presented in the present disclosure.
While the present disclosure has been described with reference to the above embodiments, it should be understood that the invention is not limited thereto, but may be variously modified and modified by those skilled in the art without departing from the spirit and scope of the present disclosure, and the scope of the present disclosure is accordingly defined by the appended claims.
Claims (13)
1. A method of driving a fan, comprising:
Driving a first fan according to a first driving signal and driving a second fan according to a second driving signal;
Obtaining a first rotating speed signal from the first fan and a second rotating speed signal from the second fan, wherein the first rotating speed signal has a first phase and the second rotating speed signal has a second phase;
Comparing the difference between the second phase and the first phase to obtain a detected phase difference when the frequency maintenance of the first rotational speed signal is stable; and
Selectively increasing or decreasing a duty ratio of the second driving signal according to the detected phase difference to adjust the second phase to maintain a predetermined phase difference with the first phase;
The fan driving method further comprises the following steps:
Recording a plurality of signal phases of the first rotating speed signal at a plurality of starting time points of a plurality of periods of the second rotating speed signal respectively; and
The plurality of signal phases of the first rotational speed signal are compared.
2. The method of claim 1, wherein selectively increasing or decreasing the duty cycle of the second drive signal further comprises:
In a first period, according to the detected phase difference, the duty ratio of the second driving signal is increased or decreased from a first ratio to a second ratio; and
In a second period, the duty cycle of the second driving signal is restored to the first ratio.
3. The method of claim 1, wherein selectively increasing or decreasing the duty cycle of the second drive signal further comprises:
During an adjustment period in a first period, the duty ratio of the second driving signal is increased or decreased from a first ratio to a second ratio according to the detected phase difference; and
The duty cycle of the second driving signal is restored to the first ratio during a restoration period in the first period.
4. The method of claim 3, wherein the duty cycle of the second driving signal is progressively restored to the first ratio during the restoring period.
5. The fan driving method as claimed in claim 3, further comprising:
judging whether the difference between the detected phase difference and the preset phase difference is within 5%.
6. The method of claim 1, wherein the first rotational speed signal has a first frequency and the second rotational speed signal has a second frequency, the method further comprising:
judging whether the first frequency is stable;
comparing the difference between the second frequency and the first frequency when the first frequency is unstable to obtain a detected frequency difference; and
Selectively increasing or decreasing the duty ratio of the second driving signal according to the detected frequency difference, so that the second frequency is changed towards the first frequency.
7. The method of claim 6, wherein the second fan is configured to receive the first rotational speed signal from the first fan and determine whether the first frequency is stable.
8. A fan system, comprising:
the first fan is used for running according to a first driving signal to generate a first rotating speed signal, wherein the first rotating speed signal has a first phase; and
The second fan is electrically connected with the first fan and is used for running according to a second driving signal to generate a second rotating speed signal, wherein the second rotating speed signal is provided with a second phase, and the second fan is used for receiving the first rotating speed signal so as to obtain a detection phase difference between the second phase and the first phase; the second fan is also used for selectively increasing or decreasing a duty ratio of the second driving signal according to the detected phase difference, so that the second phase is adjusted to maintain a preset phase difference with the first phase;
wherein the method further comprises the following steps: at a plurality of initial time points of a plurality of periods of the second rotating speed signal, the second fan is used for respectively recording a plurality of signal phases of the first rotating speed signal and comparing the plurality of signal phases of the first rotating speed signal.
9. The fan system of claim 8, wherein in a first period, the second fan increases or decreases the duty cycle of the second driving signal from a first ratio to a second ratio according to the detected phase difference; in a second period, the second fan restores the duty ratio of the second driving signal to the first ratio.
10. The fan system of claim 8, wherein during an adjustment period in a first period, the second fan increases or decreases the duty cycle of the second driving signal from a first ratio to a second ratio according to the detected phase difference; during a recovery period in the first period, the second fan recovers the duty cycle of the second driving signal to the first ratio.
11. The fan system of claim 10, wherein during the recovery period the second fan progressively recovers the duty cycle of the second drive signal to the first ratio.
12. The fan system of claim 10, wherein the second fan is further configured to determine whether the difference between the detected phase difference and the predetermined phase difference is within 5%.
13. The fan system of claim 8, wherein the first rotational speed signal has a first frequency and the second rotational speed signal has a second frequency, and wherein the second fan compares the difference between the second frequency and the first frequency to obtain a detected frequency difference when the first frequency is unstable; the second fan is also used for selectively increasing or decreasing the duty ratio of the second driving signal according to the detected frequency difference, so that the second frequency changes towards the first frequency.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6257832B1 (en) * | 1999-02-04 | 2001-07-10 | Dell Usa, L.P. | Multiple fan system having means for reducing beat frequency oscillations |
| CN1574594A (en) * | 2003-05-21 | 2005-02-02 | 富士电机株式会社 | Parallel driving method for DC brushless motors |
| CN102748312A (en) * | 2011-04-21 | 2012-10-24 | 鸿富锦精密工业（深圳）有限公司 | Control device for rotating speed of fan |
| TW201437489A (en) * | 2013-03-18 | 2014-10-01 | Hon Hai Prec Ind Co Ltd | Fan driving circuit |
-
2021
- 2021-02-05 CN CN202110163483.7A patent/CN114876839B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6257832B1 (en) * | 1999-02-04 | 2001-07-10 | Dell Usa, L.P. | Multiple fan system having means for reducing beat frequency oscillations |
| CN1574594A (en) * | 2003-05-21 | 2005-02-02 | 富士电机株式会社 | Parallel driving method for DC brushless motors |
| CN102748312A (en) * | 2011-04-21 | 2012-10-24 | 鸿富锦精密工业（深圳）有限公司 | Control device for rotating speed of fan |
| TW201437489A (en) * | 2013-03-18 | 2014-10-01 | Hon Hai Prec Ind Co Ltd | Fan driving circuit |
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