U.S. patent application number 13/331520 was filed with the patent office on 2013-02-21 for fan control unit and method.
This patent application is currently assigned to HON HAI PRECISION INDUSTRY CO., LTD.. The applicant listed for this patent is YAO-TING CHANG. Invention is credited to YAO-TING CHANG.
Application Number | 20130045114 13/331520 |
Document ID | / |
Family ID | 47712781 |
Filed Date | 2013-02-21 |
United States Patent
Application |
20130045114 |
Kind Code |
A1 |
CHANG; YAO-TING |
February 21, 2013 |
FAN CONTROL UNIT AND METHOD
Abstract
A fan control unit measures the rotating speeds of the first and
second fans to calculate the relative work intensities of the two
fans. The control unit determines whether a difference between the
first work intensity and the second work intensity is within a
predetermined range. If the difference between the first work
intensity and second work intensity is not in the predetermined
range, the control unit adjusts a duty cycle of a pulse signal
output to one of the first and second fans to change the rotating
speed of one of the first and second fans to bring the difference
between the first work intensity and the second work intensity
within the predetermined range.
Inventors: |
CHANG; YAO-TING; (Tu-Cheng,
TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CHANG; YAO-TING |
Tu-Cheng |
|
TW |
|
|
Assignee: |
HON HAI PRECISION INDUSTRY CO.,
LTD.
Tu-Cheng
TW
|
Family ID: |
47712781 |
Appl. No.: |
13/331520 |
Filed: |
December 20, 2011 |
Current U.S.
Class: |
417/45 |
Current CPC
Class: |
F04D 25/166 20130101;
F04D 27/004 20130101 |
Class at
Publication: |
417/45 |
International
Class: |
F04B 49/06 20060101
F04B049/06 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 19, 2011 |
TW |
100129662 |
Claims
1. A fan control unit to control a first fan and a second fan,
comprising: a first pulse output pin connected to the first fan to
output a first pulse signal to control the first fan to rotate; a
second pulse output pin connected to the second to output a second
pulse signal to control the second fan to rotate; a first speed
receiving pin connected to the first fan to measure a rotating
speed of the first fan; and a second speed receiving pin connected
to the second fan to measure a rotating speed of the second fan;
wherein the fan control unit records the maximum possible rotating
speeds of the first and second fans, the fan control unit measures
the rotating speeds of the first and second fans to calculate a
first work intensity of the first fan and a second work intensity
of the second fan, the first work intensity of the first fan is a
relationship between the speed and the maximum possible speed of
the first fan as a percentage, the second work intensity of the
second fan is a relationship between the speed and the maximum
possible speed of the second fan as a percentage, the fan control
unit determines whether a difference in percentages between the
first work intensity and the second work intensity is within a
predetermined range, if the difference in percentages between the
first work intensity and the second work intensity is not within
the predetermined range, the fan control unit adjusts a duty cycle
of the pulse signal output to one of the first and second fans to
change the rotating speed of the corresponding one of the first and
second fans to bring the difference in percentages between the
first work intensity of the first fan and the second work intensity
of the second fan within the predetermined range.
2. The fan control unit of claim 1, wherein if the difference in
percentages between the first work intensity and the second work
intensity is not within the predetermined range, and when the first
work intensity is greater than the second work intensity, the fan
control unit increases the duty cycle of the second pulse signal
output to the second fan to increase the rotating speed of the
second fan, to bring the difference in percentages between the
first work intensity and the second work intensity within the
predetermined ranges.
3. The fan control unit of claim 1, wherein if the difference in
percentages between the first work intensity and the second work
intensity is not within the predetermined range, and when the
second work intensity is greater than the first work intensity, the
fan control unit increases the duty cycle of the first pulse signal
output to the first fan to increase the rotating speed of the first
fan, to bring the difference in percentages between the first work
intensity and the second work intensity within the predetermined
ranges.
4. A fan control method to control a first fan and a second fan,
comprising: measuring rotating speeds of the first and second fans;
calculating a first work intensity of the first fan and a second
work intensity of the second fan through a fan control unit,
wherein the first work intensity of the first fan is a relationship
between the speed and the maximum possible speed of the first fan
as a percentage, the second work intensity of the second fan is a
relationship between the speed and the maximum possible speed of
the second fan as a percentage; determining whether a difference in
percentage between the first work intensity and the second work
intensity is within a predetermined range; and adjusting a duty
cycle of a pulse signal output to one of the first fan and second
fans to change the rotating speed of the corresponding one of the
first and second fans, to bring the difference between the first
work intensity and the second work intensity within the
predetermined range, if the difference in percentages between the
first work intensity and the second work intensity is not within
the predetermined range.
5. The fan control method of claim 4, wherein the adjusting step
comprises: increasing the duty cycle of the pulse signal output to
the second fan to increase the rotating speed of the second fan to
bring the difference in percentages between the first and second
work intensities within the predetermined range, if the first work
intensity is greater than the second work intensity.
6. The fan control method of claim 4, wherein the adjusting step
comprises: increasing the duty cycle of the pulse signal output to
the first fan to increase the rotating speed of the first fan to
bring the difference in percentages between the first and second
work intensities within the predetermined range, if the second work
intensity is greater than the first work intensity.
7. A fan control method to control a first fan and a second fan,
comprising: calculating a difference between a duty cycle of a
first pulse signal output to the first fan and a duty cycle of a
second pulse signal output to the second fan; determining whether
the difference between the duty cycle of the first pulse signal and
the duty cycle of the second pulse signal is within a predetermined
range; and adjusting the duty cycle of a corresponding one of the
first and second pulse signals output to one of the first and
second fans to bring the difference between the duty cycle of the
first pulse signal and the duty cycle of the second pulse signal
within the predetermined range, if the difference between the duty
cycle of the first pulse signal and the duty cycle of the second
pulse signal is not within the predetermined range.
8. The fan control method of claim 7, wherein the adjusting step
comprises: increasing the duty cycle of the second pulse signal to
bring the difference between the duty cycle of the first pulse
signal and the duty cycle of the second pulse signal within the
predetermined range, if the duty cycle of the first pulse signal is
greater than the duty cycle of the second pulse signal.
9. The fan control method of claim 7, wherein the adjusting step
comprises: increasing the duty cycle of the first pulse signal to
bring the difference between the duty cycle of the first pulse
signal and the duty cycle of the second pulse signal within the
predetermined range, if the duty cycle of the second pulse signal
is greater than the duty cycle of the first pulse signal.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a fan control unit and a
fan control method.
DESCRIPTION OF RELATED ART
[0002] Two fans may be mounted in a computer to dissipate heat from
heat generating sources of the computer. However, when the fans
have different working speeds, heated air expelled by the fan
working at high speed may flow into the fan working at low speed,
which affects the dissipation of heat from the computer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] Many aspects of the present embodiments can be better
understood with reference to the following drawings. The components
in the drawing are not necessarily drawn to scale, the emphasis
instead being placed upon clearly illustrating the principles of
the present disclosure. Moreover, in the drawings, all the views
are schematic, and like reference numerals designate corresponding
parts throughout the several views.
[0004] FIG. 1 is a block diagram of an exemplary embodiment of a
fan control unit connected to a first fan and a second fan, wherein
the first fan is connected to a power supply, and the second fan is
connected to a motherboard.
[0005] FIG. 2 is a flowchart of an exemplary embodiment of a fan
control method.
DETAILED DESCRIPTION
[0006] The disclosure, including the accompanying drawings in which
like references indicate similar elements, is illustrated by way of
example and not by way of limitation. It should be noted that
references to "an" or "one" embodiment in this disclosure are not
necessarily to the same embodiment, and such references mean at
least one.
[0007] Referring to the FIG. 1, an embodiment of a fan control unit
10 for a first fan 20 and a second fan 30 is provided. The first
fan 20 dissipates heat generated by a power supply 40. The second
fan 30 dissipates heat generated by a motherboard 50. The fan
control unit 10 includes a first pulse output pin PWM1, a second
pulse output pin PWM2, a first speed receiving pin TACH1, and a
second speed receiving pin TACH2.
[0008] In use, the fan control unit 10 outputs a first pulse signal
to the first fan 20 through the first pulse output pin PWM1 to
control the first fan 20 to rotate. The control unit 10 outputs a
second pulse signal to the second fan 30 through the second pulse
output pin PWM2 to control the second fan 30 to rotate. The fan
control unit 10 measures the rotating speeds of the first and
second fans 20 and 30 respectively through the first and second
speed receiving pins TACH1 and TACH2. The user presets and records
the maximum possible rotating speed of the first fan 20 and of the
second fan 30 in the fan control unit 10.
[0009] Referring to FIG. 2, an exemplary embodiment of a fan
control method includes the following steps.
[0010] In step 1, the fan control unit 10 measures the rotating
speed of the first fan 20 through the first speed receiving pin
TACH1, and measures the rotating speed of the second fan 30 though
the second speed receiving pin TACH2.
[0011] In step 2, the fan control unit 10 calculates a relationship
between the speed and the maximum possible speed of the first fan
20 (a first work intensity) as a percentage and calculates in a
similar manner in relation to the second fan 30 (a second work
intensity).
[0012] In step 3, the fan control unit 10 determines whether any
difference in percentages between the first work intensity and the
second work intensity is within a first predetermined range. If the
difference in percentages between the first work intensity and the
second work intensity is within the first predetermined range, it
is assumed that there will be no crossflow or backflow adverse to
efficient operation between the first and second fans 20 and 30 and
then the procedure ends. If the difference in percentages between
the first work intensity and the second work intensity is not
within the first predetermined range, the likelihood of
crossflowing or backflowing air between the fans increases, thereby
adversely affecting the heat-dissipating abilities of the first and
second fans 20 and 30, or one of them, and the procedure goes to
step 4.
[0013] In step 4, the fan control unit 10 adjusts a duty cycle of
the pulse signal output to one of the first and second fans 20 and
30, specifically to the fan which reveals the lower work intensity,
whether this be first work intensity or a second work intensity.
The fan control unit 10 changes the rotating speed of the relevant
fan of the fans 20 and 30 to decrease the difference in percentages
between the first work intensity of the first fan 20 and the second
work intensity of the second fan 30 and bring the difference in
percentages within the first predetermined range, and the procedure
goes back to step 1. For example, if the first work intensity of
the first fan 20 is greater than the second work intensity of the
second fan 30, and the difference in percentages between the first
work intensity and the second work intensity is not within the
first predetermined range, the fan control unit 10 increases the
duty cycle of the second pulse signal output to the second fan 30
to increase the rotating speed of the second fan 30, to bring the
difference in percentages between the first work intensity of the
first fan 20 and the second work intensity of the second fan 30
within the first predetermined range. If the second work intensity
is greater than the first work intensity, and the difference in
percentage between the first work intensity and the second work
intensity is not within the first predetermined range, the fan
control unit 10 increases the duty cycle of the first pulse signal
output to the first fan 20 to increase the rotating speed of the
first fan 20, to bring the difference in percentages between the
first work intensity of the first fan 20 and the second work
intensity of the second fan 30 within the first predetermined
range.
[0014] In other embodiments, the fan control unit 10 can directly
calculate a difference between the duty cycle of the first pulse
signal output to the first fan 20 and the duty cycle of the second
pulse signal output to the second fan 30. The fan control unit 10
may determine whether the difference is within or outside a second
predetermined range. If the difference between the cycle duties of
the first pulse signal and the second pulse signal is outside a
second predetermined range, it denotes that the heated air expelled
by one of the first and second fans 20 and 30 with high duty cycle
will flow into the other one of the first and second fans 20 and 30
with low duty cycle. The fan control unit 10 increases the duty
cycle of the other one of the first and second pulse signals output
to the other one of the first and second fans 20 and 30 with low
high duty cycle to bring the difference between the cycle duties of
the first pulse signal and the second pulse signal within the
second predetermined range.
[0015] Although numerous characteristics and advantages of the
embodiments have been set forth in the foregoing description,
together with details of the structure and function of the
embodiments, the disclosure is illustrative only, and changes may
be made in detail, especially in the matters of shape, size, and
arrangement of parts within the principles of the embodiments to
the full extent indicated by the broad general meaning of the terms
in which the appended claims are expressed.
* * * * *