U.S. patent application number 13/707672 was filed with the patent office on 2014-05-29 for fan control circuit.
This patent application is currently assigned to HON HAI PRECISION INDUSTRY CO., LTD.. The applicant listed for this patent is HON HAI PRECISION INDUSTRY CO., LTD., HONG FU JIN PRECISION INDS (SHENZHEN) CO., LTD. Invention is credited to BO TIAN, KANG WU.
Application Number | 20140147289 13/707672 |
Document ID | / |
Family ID | 50773464 |
Filed Date | 2014-05-29 |
United States Patent
Application |
20140147289 |
Kind Code |
A1 |
TIAN; BO ; et al. |
May 29, 2014 |
FAN CONTROL CIRCUIT
Abstract
A control circuit controls a fan to cool an integrated baseboard
management controller (iBMC) in a server. The control circuit
includes a state determination module. When the server is powered
off and the iBMC is operating, the system power signal from a power
supply unit (PSU) of the server is at a low level, the state signal
from the iBMC is at a low level signal, the fan operates. When the
server and the iBMC are powered off, the system power signal from
the PSU is at a low level, and the state signal from the iBMC is at
a high level, the fan is powered off. When the server is operating,
the system power signal from the PSU is at a high level, the fan is
powered off.
Inventors: |
TIAN; BO; (Shenzhen, CN)
; WU; KANG; (Shenzhen, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HONG FU JIN PRECISION INDS (SHENZHEN) CO., LTD
HON HAI PRECISION INDUSTRY CO., LTD. |
Shenzhen
New Taipei |
|
CN
TW |
|
|
Assignee: |
HON HAI PRECISION INDUSTRY CO.,
LTD.
New Taipei
TW
HONG FU JIN PRECISION INDUSTRY (ShenZhen) CO., LTD.
Shenzhen
CN
|
Family ID: |
50773464 |
Appl. No.: |
13/707672 |
Filed: |
December 7, 2012 |
Current U.S.
Class: |
417/45 |
Current CPC
Class: |
F04D 27/008 20130101;
H05K 7/20836 20130101 |
Class at
Publication: |
417/45 |
International
Class: |
F04D 27/00 20060101
F04D027/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 26, 2012 |
CN |
201210485632.2 |
Claims
1. A control circuit set in a server, the control circuit controls
a fan to cool an integrated baseboard management controller (iBMC)
in the server, the control circuit comprising: a state
determination module, comprising a NOR gate and a first electronic
switch, wherein two input terminals of the NOR gate are
respectively connected to the iBMC and a power supply unit (PSU) of
the server, for receiving a state signal of the iBMC and a system
power signal from the PSU, an output terminal of the NOR gate is
connected to a control terminal of the first electronic switch, a
first terminal of the first electronic switch is connected to the
PSU, a second terminal of the first electronic switch is connected
to a power pin of the fan; wherein when the server is powered off
and the iBMC is operating, the system power signal from the PSU is
at a low level, the state signal from the iBMC is at a low level
signal, the NOR gate outputs a high level signal, the first
terminal of the first electronic switch is connected to the second
terminal of the first electronic switch, to connect the PSU and the
fan, the fan operates; when the server and the iBMC are powered
off, the system power signal from the PSU is at a low level, and
the state signal from the iBMC is at a high level, the NOR gate
outputs a low level signal, the first terminal of the first
electronic switch is disconnected from the second terminal of the
first electronic switch, the PSU is disconnected from the fan, the
fan is powered off; and when the server is operating, the system
power signal from the PSU is at a high level, the NOR gate outputs
a low level signal, the first terminal of the first electronic
switch is disconnected from the second terminal of the first
electronic switch, the PSU is disconnected from the fan, the fan is
powered off.
2. The control circuit of claim 1, wherein the first electronic
switch is a metal oxide semiconductor field effect transistor
(MOSFET), a gate of the MOSFET is the control terminal of the first
electronic switch, a source of the MOSFET is the first terminal of
the first electronic switch, and a drain of the MOSFET is the
second terminal of the first electronic switch.
3. The control circuit of claim 1, further comprising: a
temperature measurement module connected to the state determination
module, wherein when the server is powered off and the iBMC is
operating, the state determination module further connects to the
PSU and the temperature measurement module, the temperature
measurement module measures temperature of the iBMC and outputs
corresponding pulse-width modulation (PWM) signals; and a speed
adjustment circuit connected to the temperature measurement module
and the fan, wherein the speed adjustment circuit adjusts a speed
of the fan according to the PWM signals from the temperature
measurement module.
4. The control circuit of claim 3, wherein the speed adjustment
module comprises: a second electronic switch comprising a control
terminal connected to the temperature measurement module, a first
terminal grounded, and a second terminal connected to the state
determination module through a first resistor; and a third
electronic switch comprising a control terminal connected to the
second terminal of the second electronic switch, a first terminal
grounded, and a second terminal connected to the state
determination module through a second resistor, and connected to a
control pin of the fan.
5. The control circuit of claim 4, wherein the second electronic
switch is a bipolar junction transistor (BJT), a base of the BJT is
the control terminal of the second electronic switch, an emitter of
the BJT is the first terminal of the second electronic switch, and
a collector of the BJT is the second terminal of the second
electronic switch.
6. The control circuit of claim 4, wherein the third electronic
switch is a bipolar junction transistor (BJT), a base of the BJT is
the control terminal of the third electronic switch, an emitter of
the BJT is the first terminal of the third electronic switch, and a
collector of the BJT is the second terminal of the third electronic
switch.
7. The control circuit of claim 4, wherein the temperature
measurement module is further connected to speed pins of the fan
for receiving speed signals of the fan, and adjusting the PWM
signals from the temperature measurement module to adjust the speed
of the fan.
8. The control circuit of claim 7, wherein the temperature
measurement module comprises a temperature sensor, first to fourth
voltage sensing pins of the temperature sensor are grounded through
first to fourth thermistors respectively, the first to fourth
voltage sensing pins of the temperature sensor are further
connected to a first terminal of a first capacitor through third to
sixth resistors respectively, a second terminal of the first
capacitor is grounded; a first ground pin of the temperature sensor
is grounded through a second capacitor, a second ground pin of the
temperature sensor is grounded; a first power pin of the
temperature sensor is connected to the second terminal of the first
electronic switch, and is further grounded through a third
capacitor; a second power pin of the temperature sensor is
connected to the second terminal of the first electronic switch,
and is further grounded through a fourth capacitor; a pulse pin of
the temperature sensor is connected to the control terminal of the
second electronic switch through a seventh resistor; a first
control pin of the temperature sensor is connected to a first speed
pin of the fan through an eighth resistor, a second control pin of
the temperature sensor is connected to a second speed pin of the
fan through a ninth resistor.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] The present disclosure relates to a circuit for controlling
a fan.
[0003] 2. Description of Related Art
[0004] In current servers, integrated baseboard management
controllers (iBMCs) are often used. However, there are no special
fans to cool the iBMCs. This may result in overheating of the
iBMCs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Many aspects of the embodiments can be better understood
with reference to the following drawing. The components in the
drawings are not necessarily drawn to scale, the emphasis instead
being placed upon clearly illustrating the principles of the
present embodiments. Moreover, in the drawings, like reference
numerals designate corresponding parts throughout the view.
[0006] FIG. 1 is a block diagram of an exemplary embodiment of a
control circuit for a fan.
[0007] FIGS. 2-4 are circuit diagrams of the different components
of the control circuit of FIG. 1.
DETAILED DESCRIPTION
[0008] The disclosure, including the accompanying drawings, is
illustrated by way of examples 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.
[0009] FIG. 1 shows an embodiment of a control circuit. The control
circuit is to control a fan 2 for cooling an integrated baseboard
management controller (iBMC) 1 in a server 100. The control circuit
includes a temperature measurement module 10, a state determination
module 12, and a speed adjustment module 15.
[0010] The state determination module 12 is connected to the iBMC 1
and a power supply unit (PSU) 16 of the server 100, to determine
states of the iBMC 1 and the server 100, and outputs corresponding
determination signals. The state determination module 12 further
supplies power to the fan 2 as needed according to the
determination result. The state determination module 12 is further
connected to the temperature measurement module 10 and the speed
adjustment module 15. The state determination module 12 further
supplies power to the temperature measurement module 10 and the
speed adjustment module 15 as needed according to the determination
result.
[0011] The temperature determination module 10 is to measure
ambient temperature in the vicinity of the iBMC 1. The temperature
determination module 10 outputs corresponding pulse-width
modulation (PWM) signals to the speed adjustment module 15 for
controlling the fan 2. In the embodiment, the PSU 16 supplies a
standby power signal P3V3_STBY.
[0012] Referring to FIG. 2, the state determination module 12
includes a NOR gate U2 and a metal oxide semiconductor field effect
transistor (MOSFET) Q3. A first input terminal of the NOR gate U2
is connected to the iBMC 1 for receiving a state signal BMC WORK OK
from the iBMC 1. A second input terminal of the NOR gate U2 is
connected to the PSU 16 for receiving a system power signal
P3V3_SYS from the PSU 16. An output terminal of the NOR gate U2 is
connected to a gate of the MOSFET Q3. A source of the MOSFET Q3 is
connected to a dual power signal P3V3_AUX. A drain of the MOSFET Q3
is to supply a power signal P3V3_S1 to the fan 2 and the
temperature measurement module 10. In the embodiment, the dual
power signal P3V3_AUX is converted from the system power signal
P3V3_SYS or the standby power signal P3V3_STBY.
[0013] Referring to FIG. 3, the speed adjustment module 15 includes
two bipolar junction transistors (BJTs) Q1 and Q2. A base of the
BJT Q2 is connected to the source of the MOSFET Q3 through
resistors R2 and R1 in that order, to receive the dual power signal
P3V3_AUX. A node between the resistors R2 and R1 is connected to
the temperature measurement module 10. An emitter of the BJT Q2 is
grounded. A collector of the BJT Q2 is connected to the drain of
the MOSFET Q3 through a resistor R3. The collector of the BJT Q2 is
further connected to a base of the BJT Q1. An emitter of the BJT Q1
is grounded. A collector of the JTB Q1 is connected to the drain of
the MOSFET Q3 through a resistor R4. The collector of the BJT Q2 is
further connected to a pulse pin PWM of the fan 2. A power pin VCC
of the fan 2 is connected to the drain of the MOSFET Q3 for
receiving the power signal P3V3_S1. A ground pin GND of the fan 2
is grounded. Speed pins TACH1 and TACH2 of the fan 2 are connected
to the temperature measurement module 10.
[0014] Referring to FIG. 4, the temperature determination module 10
includes a temperature sensor U1. Voltage sensing pins VSEN2,
VSEN4, VSEN 6, and VSEN8 of the temperature sensor U1 are grounded
through thermistors TH1, TH2, TH3, and TH4 respectively. The
voltage sensing pins VSEN2, VSEN4, VSEN 6, and VSEN8 of the
temperature sensor U1 are further connected to a first terminal of
a capacitor C2 through resistors R5, R6, R7, and R8 respectively. A
second terminal of the capacitor C2 is grounded. Voltage sensing
pins VSEN3 and VSEN5 of the temperature sensor U1 are grounded. A
first ground pin VREF of the temperature sensor U1 is grounded
through the capacitor C2. A second ground pin GND of the
temperature sensor U1 is grounded. A first power pin 3VDD of the
temperature sensor U1 is connected to the drain of the MOSFET Q3
for receiving the power signal P3V3_S1, and is further grounded
through a capacitor C3. A capacitor C4 is connected to the
capacitor C3 in parallel. A second power pin 3VSB of the
temperature sensor U1 is connected to the drain of the MOSFET Q3
for receiving the power signal P3V3_S1, and is further grounded
through a capacitor C5. A capacitor C6 is connected to the
capacitor C5 in parallel.
[0015] A pulse pin PWM of the temperature sensor U1 is connected to
the node between the resistors R1 and R2 through a resistor R9. A
first control pin FAN1 of the temperature sensor U1 is connected to
the speed pin TACH1 of the fan 2 through a resistor R10. A second
control pin FAN2 of the temperature sensor U2 is connected to the
speed pin TACH2 of the fan 2 through a resistor R11. The
temperature sensor U1 measures a voltage difference of the
thermistors TH1-TH4 to obtain any temperature changes, and outputs
corresponding PWM signals.
[0016] When the server 100 is operating, the system power signal
P3V3_SYS from the PSU 16 is at a high level. When the server 100 is
powered off, the system power signal P3V3_SYS from the PSU 16 is at
a low level. When the iBMC 1 is operating, the state signal
BMC_WORK_OK from the iBMC 1 is at a low level. When the iBMC 1 is
powered off, the state signal BMC_WORK_OK from the iBMC 1 is at a
high level.
[0017] In the embodiment, the temperature sensor U1 is located near
the iBMC 1 for measuring a temperature of the iBMC 1.
[0018] When the server 100 is powered off and the iBMC 1 is
operating, the state signal BMC_WORK_OK from the iBMC 1 is at a low
level, and the system power signal P3V3_SYS is at a low level. As a
result, the input terminals of the NOR gate U2 receive low level
signals. The MOSFET Q3 is turned on. The standby power signal
P3V3_STBY is transmitted to the temperature measurement module 10
and the fan 2 through the MOSFET Q3. The temperature measurement
module 10 measures the temperature of the iBMC 1, and outputs
corresponding PWM signals, according to the temperature, to the
speed adjustment module 15. The speed adjustment module 15 controls
the fan 2 according to the PWM signals. In addition, a speed of the
fan 2 is fedback to the temperature sensor U1 through the speed
pins TACH1 and TACH2 of the fan 2. The temperature sensor U1
adjusts the fan 2 accordingly.
[0019] When the server 100 and the iBMC are powered off, the state
signal BMC_WORK_OK from the iBMC 1 is at a high level, and the
system power signal P3V3_SYS from the PSU 16 is at a low level. As
a result, the output terminal of the NOR gate U2 outputs a low
level signal. The MOSFET Q3 is turned off. The fan 2 is not
operating.
[0020] When the server 100 is operating, the system power signal
P3V3_SYS from the PSU 16 is at a high level. In this state, whether
the iBMC 1 is operating or powered off, the NOR gate U5 outputs a
low level signal. The MOSFET Q3 is turned off. The fan 2 is powered
off. Under these circumstances, the server 100 is operating, and a
system fan (not shown) of the server 100 is operating, so the iBMC
1 can be cooled by airflow from the system fan of the server 100.
The fan 2 is powered off to save power.
[0021] In other embodiments, if the refinement of speed control is
not needed, the speed adjustment module 15 and the temperature
measurement module 10 can be omitted. In other words, the control
circuit could activate or deactivate the fan 2, but not adjust the
speed of the fan 2. In addition, the BJTs Q1 and Q2, and the MOSFET
Q3 function as electronic switches.
[0022] The foregoing description of the exemplary embodiments of
the disclosure has been presented only for the purposes of
illustration and description and is not intended to be exhaustive
or to limit the disclosure to the precise forms disclosed. Many
modifications and variations are possible in light of disclosure
above. The embodiments were chosen and described in order to
explain the principles of the disclosure and their practical
application so as to enable others of ordinary skill in the art to
utilize the disclosure and various embodiments and with various
modifications as are suited to the particular use contemplated.
Alternative embodiments will become apparent to those of ordinary
skills in the art to which the present disclosure pertains without
departing from its spirit and scope. Accordingly, the scope of the
present disclosure is defined by the appended claims rather than
the foregoing description and the exemplary embodiments described
therein.
* * * * *