CN114857059A

CN114857059A - Fan system and fan driving method

Info

Publication number: CN114857059A
Application number: CN202110147689.0A
Authority: CN
Inventors: 李文定; 曹又中
Original assignee: Sentelic Corp
Current assignee: Sentelic Corp
Priority date: 2021-02-03
Filing date: 2021-02-03
Publication date: 2022-08-05
Anticipated expiration: 2041-02-03
Also published as: CN114857059B

Abstract

The present disclosure relates to a fan system and a fan driving method. The fan driving method comprises the following steps: the processor transmits a first control signal to the first fan and the second fan; judging whether a first control frequency of the first control signal is positioned in a first frequency band and a second frequency band, wherein the first frequency band and the second frequency band are different; when the first control frequency is in the first frequency band, adjusting the rotating speed of the first fan according to the first control signal; and when the first control frequency is in the second frequency band, adjusting the rotating speed of the second fan according to the first control signal. Accordingly, the processor can selectively and respectively adjust the rotating speed of each fan so as to improve the operability and controllability of the fan system.

Description

Fan system and fan driving method

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 capable of controlling the rotation speeds of a plurality of fans respectively.

Background

With the development of technology, the operating frequency of various electronic devices increases, but the increase of the operating frequency causes the internal temperature of the electronic device to increase relatively when the electronic device is operated, so that the fan is essential to maintain the operation of the electronic device in order to prevent the high temperature from affecting the operation of the electronic device and even damaging the electronic device.

The fan system usually 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 is often fluctuated due to various variables or different operation requirements, and may also need to be adjusted according to the power supply requirement.

Disclosure of Invention

The present disclosure relates to a fan driving method, comprising the following steps: transmitting a first control signal to the first fan and the second fan through the processor, wherein the first control signal has a first control frequency; judging whether the first control frequency is positioned in a first frequency band and a second frequency band, wherein the first frequency band is different from the second frequency band; when the first control frequency is in the first frequency band, adjusting the rotating speed of the first fan according to the first control signal; and when the first control frequency is in the second frequency band, adjusting the rotating speed of the second fan according to the first control signal.

In one embodiment, the fan driving method further includes: transmitting a second control signal to the first fan through the processor, wherein the second control signal has a second control frequency; judging whether the second control frequency is positioned in the first frequency band; when the second control frequency is in the first frequency band, adjusting the rotating speed of the first fan according to the second control signal; and when the second control frequency is not in the first frequency band, maintaining the rotating speed of the first fan according to the first control signal.

In one embodiment, the fan driving method further includes: judging whether the first control frequency is located in a common frequency band, wherein the common frequency band is different from the first frequency band and the second frequency band; and when the first control frequency is in the common frequency band, adjusting the rotating speeds of the first fan and the second fan according to the first control signal.

In one embodiment, the fan driving method further includes: detecting the current rotating speed of the first fan through a first detector in the first fan to generate a first rotating speed signal; and transmitting the first rotational speed signal to a processor.

In one embodiment, a method for adjusting a rotation speed of a first fan according to a first control signal includes: obtaining a first duty ratio of a first control signal; a first motor in the first fan is driven according to a first duty cycle.

The present disclosure also relates to a fan system including a first fan, a second fan, and a processor. The first fan is electrically connected to the driving power source and driven according to the driving power. The second fan is electrically connected to the driving power source and driven according to the driving power. The processor is electrically connected to the first fan and the second fan and is used for transmitting a first control signal to the first fan and the second fan. When the first fan determines that the first control frequency of the first control signal is in the first frequency band, the first fan adjusts the rotating speed of the first fan according to the first control signal. When the second fan judges that the first control frequency of the first control signal is in the second frequency band, the second fan adjusts the rotating speed of the second fan according to the first control signal.

In an embodiment, when the first fan determines that the first control frequency is in the first frequency band, the first fan obtains a first duty ratio of the first control signal to adjust a rotation speed of the first fan.

In one embodiment, the processor is further configured to transmit a second control signal to the first fan and the second fan; when the first fan judges that the second control frequency of the second control signal is located in the first frequency band, the first fan adjusts the rotating speed of the first fan according to the second control signal; when the first fan judges that the second control frequency of the second control signal is not located in the first frequency band, the first fan maintains the rotating speed of the first fan according to the first control signal.

In one embodiment, the first fan and the second fan are electrically connected to the same signal contact of the processor to receive the first control signal.

In one embodiment, when the first fan is running, the first fan detects the current rotation speed and transmits a first rotation speed signal to the processor.

In one embodiment, the first fan includes a first controller, a first motor, and a first detector. The first controller is electrically connected to the processor and used for generating a first driving signal according to a first duty ratio in the first control signal. The first motor is electrically connected with the first controller to drive the first fan blade according to the first driving signal. The first detector is electrically connected to the processor and is used for detecting the position of the rotor of the first motor or the position of the fan blade of the first fan blade.

The present disclosure also relates to a fan driving method, comprising the following steps: transmitting an initial control signal to the plurality of fans through the processor, so that the fans start to operate according to the initial control signal, wherein the initial control signal has an initial control frequency, and a plurality of signal frequency bands are stored in the fans and are different from each other; transmitting a first control signal to the fan, wherein the first control signal has a first control frequency different from the initial control frequency; when the first control frequency corresponds to one of the signal frequency bands, adjusting the rotating speed of the corresponding one of the fans according to the first control signal; and maintaining the rotating speed of the rest fans according to the initial control signal.

In one embodiment, a method for adjusting a rotation speed of a corresponding one of the fans according to a first control signal includes: obtaining a first duty ratio of a first control signal; and driving the motor of the corresponding one of the fans according to the first duty ratio.

In one embodiment, the fan driving method further includes: detecting a plurality of current rotating speeds of the fans through a plurality of detectors in the fans to generate a plurality of rotating speed signals; and transmitting the rotation speed signals to a processor.

In one embodiment, the fans further store a common frequency band, and the initial control frequency corresponds to the common frequency band.

The present disclosure uses the frequency of the control signal as a determination basis, so that the processor can selectively and respectively adjust the rotation speed of each fan, thereby improving the operability and controllability of the fan system.

Drawings

FIG. 1 is a schematic view of a fan system according to some embodiments of the present disclosure;

FIG. 2 is a schematic diagram of a fan system according to some embodiments of the present disclosure;

FIG. 3 is a schematic diagram of control signals according to some embodiments of the present disclosure;

FIG. 4 is a flow chart of a fan driving method according to some embodiments of the present disclosure;

fig. 5A-5C are schematic diagrams illustrating operation states of a fan system according to some embodiments of the disclosure.

[ notation ] to show

100 fan system

110 the first fan

111 first controller

112 first motor

113 first detector

114 first fan blade

120 the second fan

121: second controller

122 second motor

123 second detector

124 the second fan blade

130 the third fan

140 fourth fan

150 processor

VDD drive Power supply

Sdi control signal

S0 initial control signal

S1 first control signal

S2 second control signal

Sf1-Sf4 rotating speed signal

Period of P

High level period of Th

Tl during low level

S401-S409 step

Detailed Description

In the following description, for purposes of explanation, numerous implementation details are set forth in order to provide a thorough understanding of the various embodiments of the present invention. It should be understood, however, that these implementation details are not to be interpreted as limiting the invention. That is, in some embodiments of the invention, such implementation details are not necessary. In addition, for the sake of simplicity, some conventional structures and elements are shown in the drawings in a simple schematic manner.

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 be used to indicate that two or more elements are in mutual engagement or interaction. Moreover, although terms such as "first," "second," …, etc., may be used herein to describe various elements, these terms are used merely to distinguish one element or operation from another element or operation described in similar technical terms. Unless the context clearly dictates otherwise, the terms do not specifically refer or imply an order or sequence nor are they intended to limit the invention.

FIG. 1 is a schematic diagram of a fan system 100 according to some embodiments of the present disclosure. The fan system 100 includes a processor 150 and a plurality of

fans

110 and 140. The

fans

110 and 140 are electrically connected to the driving power VDD to receive the driving power and operate according to the control signal Sdi transmitted from the processor 150.

During operation, the first fan 110 will sense the current speed to generate the first speed signal Sf 1. Similarly, the fan 120/130/140 detects the current speed to generate the corresponding speed signal Sf1-Sf 4. The rotational speed signal is transmitted back to the processor 150, so that the processor 150 can know the current operating status of the

fans

110 and 140 accordingly.

FIG. 2 is a diagram of a fan system 100 and an internal structure of a fan according to some embodiments of the disclosure. To keep the drawing simplified, only the

fans

110, 120 are depicted in fig. 2. As shown, 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 controller 111/121 generates corresponding driving signals according to the control signal Sdi provided by the processor 150 and the driving power provided by the driving power supply VDD, so as to adjust the power provided to the motor 112/122, and further drive the fan 114/124 to rotate.

In some embodiments, the control signal Sdi is in the form of Pulse Width Modulation (PWM). The duty cycle (duty) of the control signal Sdi is used to indicate the desired rotational speed of the fan. For example, when the duty ratio of the control signal is 60%, the rotation speed of the fan is 60% of the maximum rotation speed.

The speed signals Sf1-Sf4 are used to reflect the current speeds of the

fans

110 and 140. 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 114/124 or the motor 112/122, thereby generating the rotational speed signal. The tacho signal may also be in the form of pulse width modulation. The detector 113/123 may be, but is not limited to, a position sensor. In some other embodiments, a detector in the fan may receive feedback current from the motor 112/122 to calculate the current position of the fan blade or the motor rotor. Since the generation of the rotation speed signal can be understood by those skilled in the art, it is not described herein.

In an embodiment, the

fans

110 and 140 are electrically connected to the same signal contact of the processor 150 to receive the control signal Sdi. In other words, the processor 150 transmits the same control signal Sdi to all of the

fans

110 and 140 through the same output path. In some embodiments, the fan system 100 can be applied to a server or a computer system, and the rotation speeds of the

fans

110 and 140 are controlled by the same processor 150.

In one approach, because the fans are adjusted in rotation speed according to the duty ratios of the control signals, if different fans are to operate at different rotation speeds, the processor must transmit different control signals to each fan independently through different transmission paths. However, this control method is equivalent to controlling each fan independently, and cannot save the number of pins on the processor. The present disclosure uses the "frequency" of the control signal Sdi as a determination parameter to realize different rotation speed control modes without changing the number of contacts and the arrangement mode of the processor 150.

In one embodiment, the first fan 110 stores a first frequency band, and the second fan stores a second frequency band (e.g., a memory stored in the fan). The first frequency range and the second frequency range are different, for example, the first frequency range is 27KHz + -500 Hz, and the second frequency range is 28KHz + -500 Hz. When the fan 110/120 receives the control signal Sdi, the fan 110/120 will first determine whether the control frequency in the control signal is within the internally stored frequency band? And if so, adjusting the rotating speed according to the received control signal. If not, the fan 110/120 ignores the current control signal and continues to maintain the same speed according to the previous control signal (i.e., the frequency corresponding to the frequency band stored in the fan).

For example: if the first control frequency of the first control signal is 57.2KHz, which corresponds to the first frequency band, the first fan 110 will adjust the rotation speed according to the first control signal, but the second fan 120 will not adjust the rotation speed according to the first control signal. Similarly, if the first control frequency of the first control signal is 58.2KHz, which corresponds to the second frequency band, the first fan 110 does not adjust the rotation speed according to the first control signal, but the second fan 120 adjusts the rotation speed according to the first control signal.

Accordingly, if the processor 150 sends the first control signal to the

fans

110 and 120, the first fan 110 adjusts the rotation speed according to the first control signal, but the second fan 120 does not adjust the rotation speed according to the first control signal. Then, the processor 150 instead sends a second control signal to the

fans

110, 120. At this time, if the second control frequency of the second control signal is not located in the first frequency band but located in the second frequency band, the first fan 110 will still maintain the rotation speed according to the first control signal, but the second fan 120 will adjust the rotation speed according to the second control signal instead.

In some embodiments, all of the fans 110/120 have the same common frequency band stored therein (e.g., 25KHz 500 Hz). That is, when the control signal Sdi transmitted by the processor 150 is located in the common frequency band, all of the fans 110/120 adjust the rotation speed according to the control signal Sdi.

The

fans

110 and 120 and the stored frequency band data can be listed as follows:

as shown in fig. 2, in an embodiment, when the

fans

110 and 120 determine that the control frequency of the received control signal Sdi corresponds to the frequency band stored therein, the fan 110/120 obtains the duty ratio of the control signal Sdi and generates or adjusts the driving signal according to the duty ratio. The driving signal is used to drive the motor 112/122 to change the rotation speed of the fan 114/124.

Then, the detector 113/123 detects the rotor position of at least one rotor of the motor 112/122, or detects the position of at least one blade of the blades 114/124, or calculates the blade position according to the feedback current of the motor, so as to generate the rotation speed signals Sf1-Sf 2.

Fig. 3 is a schematic diagram of a control signal Sdi according to some embodiments of the disclosure. As shown in the figure, in each period P, the ratio of the high level period Th and the low level period Tl of the control signal Sdi is the duty ratio. For example: the high level period Th accounts for 70% of the period P, and the duty ratio is 70%. The processor 150 is able to adjust the length of the period P of the control signal Sdi to change its frequency.

FIG. 4 is a flow chart of a fan driving method according to some embodiments of the disclosure. Fig. 5A-5C are schematic diagrams illustrating the operation of the fan system 100 under different conditions. In one embodiment, all of the

fans

110, 120 are connected to the same signal pad of the processor 150 to receive the same control signal. The first fan 110 stores a first frequency band and a common frequency band. The second fan 120 stores a second frequency band and a common frequency band. The first frequency band, the second frequency band and the common frequency band have different frequency ranges. In some embodiments, the processor 150 may adjust the duty cycle and frequency of the output control frequency, and the frequency is greater than 20 kHz.

As shown in fig. 4 and 5A, in step S401, the processor 150 transmits a start control signal S0 to all

fans

110 and 120. The

fans

110, 120 also receive power from the driving power supply VDD. Since the start control frequency of the start control signal S0 is in the common frequency band, all

fans

110, 120 start to drive the motor 112/122 according to the duty cycle of the start control signal S0 and the driving circuit.

As shown in fig. 5B, in step S402, the processor 150 transmits a first control signal S1 to all

fans

110, 120. In other words, the frequency of the control signal output by the processor 150 will be changed from the original initial control frequency to the first control frequency of the first control signal S1. The duty cycle of the control signal output by the processor 150 is also converted to the first duty cycle of the first control signal S1.

In step S403, each

fan

110, 120 respectively determines whether the first control frequency of the first control signal S1 corresponds to the frequency band stored therein, so as to determine whether to change the rotation speed. For example: the first fan 110 determines whether the first control frequency corresponds to a first frequency band, and the second fan 120 determines whether the first control frequency corresponds to a second frequency band.

If the first control frequency corresponds to one of the frequency bands, in step S404, the rotation speed of the corresponding fan is adjusted according to the first duty ratio of the first control signal S1. For example: the first control frequency corresponds to a first frequency band, and the first fan 110 adjusts the rotation speed according to the first duty ratio.

If the first control frequency does not correspond to the remaining frequency bands, the fans corresponding to the remaining frequency bands ignore the first control signal S1 and maintain the rotation speed according to the duty ratio of the previously received control signal (i.e., the start control signal S0) in step S405. For example: the first control frequency does not correspond to the second frequency band, and the second fan 120 maintains its rotation speed according to the duty ratio of the start control signal S0.

As shown in fig. 5C, in step S406, the processor 150 transmits a second control signal S2 to all

fans

110, 120. In other words, the frequency of the control signal output by the processor 150 will be changed from the first control frequency to the second control frequency of the second control signal S2. The duty cycle of the control signal output by the processor 150 is also converted to the second duty cycle of the second control signal S2.

In step S407, each

fan

110, 120 respectively determines whether the second control frequency of the second control signal S2 corresponds to the frequency band stored therein. For example: the first fan 110 determines whether the second control frequency corresponds to the first frequency band, and the second fan 120 determines whether the second control frequency corresponds to the second frequency band.

If the second control frequency corresponds to one of the frequency bands, in step S408, the rotation speed of the corresponding fan is adjusted according to the second duty ratio of the second control signal S2. For example: the second control frequency corresponds to a second frequency band, and the second fan 110 adjusts the rotation speed according to the second duty ratio.

If the second control frequency does not correspond to the rest of the frequency bands, in step S409, the fans corresponding to the frequency bands ignore the second control signal S2, and maintain the rotation speed according to the control signal received previously and having the corresponding frequency. For example: the second control frequency S2 does not correspond to the first frequency band, the first fan 110 will maintain its rotation speed according to the first duty ratio.

Referring to fig. 1, in some embodiments, the processor 150 may also store a first frequency band, a second frequency band, a third frequency band, a fourth frequency band and a common frequency band corresponding to the

fans

110 and 140, and store control signals corresponding to different rotation speeds. When there is a need to adjust the rotation speed (e.g., to adjust the local temperature in the server or receive a user control command), the processor 150 can determine the fan to be adjusted and the corresponding frequency band through a lookup table to send a control signal corresponding to the frequency.

Various elements, method steps or technical features of the foregoing embodiments may be combined with each other without limiting the order of description or presentation in the drawings in the present disclosure.

Although the present disclosure has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the disclosure, and therefore, the scope of the disclosure should be determined by that defined in the appended claims.

Claims

1. A method for driving a fan, comprising:

transmitting a first control signal to a first fan and a second fan through a processor, wherein the first control signal has a first control frequency;

judging whether the first control frequency is located in a first frequency band and a second frequency band, wherein the first frequency band is different from the second frequency band;

when the first control frequency is in the first frequency band, adjusting the rotating speed of the first fan according to the first control signal; and

when the first control frequency is in the second frequency band, the rotating speed of the second fan is adjusted according to the first control signal.

2. The fan driving method as claimed in claim 1, further comprising:

transmitting a second control signal to the first fan through a processor, wherein the second control signal has a second control frequency;

judging whether the second control frequency is in the first frequency band; and

when the second control frequency is in the first frequency band, adjusting the rotating speed of the first fan according to the second control signal; and

and when the second control frequency is not in the first frequency band, maintaining the rotating speed of the first fan according to the first control signal.

3. The fan driving method as claimed in claim 1, further comprising:

determining whether the first control frequency is located in a common frequency band, wherein the common frequency band is different from the first frequency band and the second frequency band; and

when the first control frequency is in the common frequency band, the rotating speeds of the first fan and the second fan are adjusted according to the first control signal.

4. The fan driving method as claimed in claim 1, further comprising:

detecting a current rotating speed of the first fan through a first detector in the first fan to generate a first rotating speed signal; and

the first rotation speed signal is transmitted to the processor.

5. The method as claimed in claim 1, wherein the adjusting the rotation speed of the first fan according to the first control signal comprises:

obtaining a first duty ratio of the first control signal; and

and driving a first motor in the first fan according to the first duty ratio.

6. A fan system, comprising:

the first fan is electrically connected with a driving power supply and is driven according to driving power;

the second fan is electrically connected to the driving power supply and is driven according to the driving power; and

the processor is electrically connected to the first fan and the second fan and used for transmitting a first control signal to the first fan and the second fan;

when the first fan judges that a first control frequency of the first control signal is positioned in a first frequency band, the first fan adjusts the rotating speed of the first fan according to the first control signal;

when the second fan determines that the first control frequency of the first control signal is in a second frequency band, the second fan adjusts the rotation speed of the second fan according to the first control signal.

7. The fan system as claimed in claim 6, wherein when the first fan determines that the first control frequency is within the first frequency band, the first fan obtains a first duty ratio of the first control signal to adjust the rotation speed of the first fan.

8. The fan system of claim 6, wherein the processor is further configured to send a second control signal to the first fan and the second fan; when the first fan judges that a second control frequency of the second control signal is positioned in the first frequency band, the first fan adjusts the rotating speed of the first fan according to the second control signal; when the first fan determines that the second control frequency of the second control signal is not in the first frequency band, the first fan maintains the rotating speed of the first fan according to the first control signal.

9. The fan system as claimed in claim 6, wherein the first fan and the second fan are electrically connected to a same signal contact of the processor for receiving the first control signal.

10. The fan system as claimed in claim 6, wherein the first fan detects a current speed and transmits a first speed signal to the processor when the first fan is running.

11. The fan system as claimed in claim 6, wherein the first fan comprises:

the first controller is electrically connected to the processor and used for generating a first driving signal according to a first duty ratio in the first control signal;

the first motor is electrically connected with the first controller and is used for driving a first fan blade according to the first driving signal; and

the first detector is electrically connected to the processor and is used for detecting a rotor position of the first motor or a blade position of the first blade.

12. A method for driving a fan, comprising:

transmitting an initial control signal to a plurality of fans through a processor, so that the plurality of fans start to operate according to the initial control signal, wherein the initial control signal has an initial control frequency, and a plurality of signal frequency bands are stored in the plurality of fans and are different from each other;

transmitting a first control signal to the plurality of fans, wherein the first control signal has a first control frequency different from the initial control frequency;

when the first control frequency corresponds to one of the signal frequency bands, adjusting the rotating speed of the corresponding one of the fans according to the first control signal; and

and maintaining the rotation speeds of the rest fans according to the initial control signal.

13. The method of claim 12, wherein adjusting the rotation speed of the corresponding one of the plurality of fans according to the first control signal comprises:

obtaining a first duty ratio of the first control signal; and

and driving a motor of a corresponding one of the plurality of fans according to the first duty ratio.

14. The fan driving method as claimed in claim 12, further comprising:

detecting a plurality of current rotating speeds of the plurality of fans through a plurality of detectors in the plurality of fans to generate a plurality of rotating speed signals; and

and transmitting the plurality of rotating speed signals to the processor.

15. The method as claimed in claim 12, wherein the fans further store a common frequency band, and the initial control frequency corresponds to the common frequency band.