US20140147289A1 - Fan control circuit - Google Patents
Fan control circuit Download PDFInfo
- Publication number
- US20140147289A1 US20140147289A1 US13/707,672 US201213707672A US2014147289A1 US 20140147289 A1 US20140147289 A1 US 20140147289A1 US 201213707672 A US201213707672 A US 201213707672A US 2014147289 A1 US2014147289 A1 US 2014147289A1
- Authority
- US
- United States
- Prior art keywords
- terminal
- electronic switch
- fan
- ibmc
- psu
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
-
- 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
-
- 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
- F04D27/008—Stop safety or alarm devices, e.g. stop-and-go control; Disposition of check-valves
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K7/00—Constructional details common to different types of electric apparatus
- H05K7/20—Modifications to facilitate cooling, ventilating, or heating
- H05K7/20709—Modifications to facilitate cooling, ventilating, or heating for server racks or cabinets; for data centers, e.g. 19-inch computer racks
- H05K7/20836—Thermal management, e.g. server temperature control
Definitions
- the present disclosure relates to a circuit for controlling a fan.
- FIG. 1 is a block diagram of an exemplary embodiment of a control circuit for a fan.
- FIGS. 2-4 are circuit diagrams of the different components of the control circuit of FIG. 1 .
- 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 .
- 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.
- 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 .
- PWM pulse-width modulation
- the PSU 16 supplies a standby power signal P 3 V 3 _STBY.
- the state determination module 12 includes a NOR gate U 2 and a metal oxide semiconductor field effect transistor (MOSFET) Q 3 .
- a first input terminal of the NOR gate U 2 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 U 2 is connected to the PSU 16 for receiving a system power signal P 3 V 3 _SYS from the PSU 16 .
- An output terminal of the NOR gate U 2 is connected to a gate of the MOSFET Q 3 .
- a source of the MOSFET Q 3 is connected to a dual power signal P 3 V 3 _AUX.
- a drain of the MOSFET Q 3 is to supply a power signal P 3 V 3 _S 1 to the fan 2 and the temperature measurement module 10 .
- the dual power signal P 3 V 3 _AUX is converted from the system power signal P 3 V 3 _SYS or the standby power signal P 3 V 3 _STBY.
- the speed adjustment module 15 includes two bipolar junction transistors (BJTs) Q 1 and Q 2 .
- a base of the BJT Q 2 is connected to the source of the MOSFET Q 3 through resistors R 2 and R 1 in that order, to receive the dual power signal P 3 V 3 _AUX.
- a node between the resistors R 2 and R 1 is connected to the temperature measurement module 10 .
- An emitter of the BJT Q 2 is grounded.
- a collector of the BJT Q 2 is connected to the drain of the MOSFET Q 3 through a resistor R 3 .
- the collector of the BJT Q 2 is further connected to a base of the BJT Q 1 .
- An emitter of the BJT Q 1 is grounded.
- a collector of the JTB Q 1 is connected to the drain of the MOSFET Q 3 through a resistor R 4 .
- the collector of the BJT Q 2 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 Q 3 for receiving the power signal P 3 V 3 _S 1 .
- a ground pin GND of the fan 2 is grounded.
- Speed pins TACH 1 and TACH 2 of the fan 2 are connected to the temperature measurement module 10 .
- the temperature determination module 10 includes a temperature sensor U 1 .
- Voltage sensing pins VSEN 2 , VSEN 4 , VSEN 6 , and VSEN 8 of the temperature sensor U 1 are grounded through thermistors TH 1 , TH 2 , TH 3 , and TH 4 respectively.
- the voltage sensing pins VSEN 2 , VSEN 4 , VSEN 6 , and VSEN 8 of the temperature sensor U 1 are further connected to a first terminal of a capacitor C 2 through resistors R 5 , R 6 , R 7 , and R 8 respectively. A second terminal of the capacitor C 2 is grounded.
- Voltage sensing pins VSEN 3 and VSEN 5 of the temperature sensor U 1 are grounded.
- a pulse pin PWM of the temperature sensor U 1 is connected to the node between the resistors R 1 and R 2 through a resistor R 9 .
- a first control pin FAN 1 of the temperature sensor U 1 is connected to the speed pin TACH 1 of the fan 2 through a resistor R 10 .
- a second control pin FAN 2 of the temperature sensor U 2 is connected to the speed pin TACH 2 of the fan 2 through a resistor R 11 .
- the temperature sensor U 1 measures a voltage difference of the thermistors TH 1 -TH 4 to obtain any temperature changes, and outputs corresponding PWM signals.
- the temperature sensor U 1 is located near the iBMC 1 for measuring a temperature of the iBMC 1 .
- the state signal BMC_WORK_OK from the iBMC 1 is at a low level, and the system power signal P 3 V 3 _SYS is at a low level.
- the input terminals of the NOR gate U 2 receive low level signals.
- the MOSFET Q 3 is turned on.
- the standby power signal P 3 V 3 _STBY is transmitted to the temperature measurement module 10 and the fan 2 through the MOSFET Q 3 .
- 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.
- a speed of the fan 2 is fedback to the temperature sensor U 1 through the speed pins TACH 1 and TACH 2 of the fan 2 .
- the temperature sensor U 1 adjusts the fan 2 accordingly.
- the state signal BMC_WORK_OK from the iBMC 1 is at a high level, and the system power signal P 3 V 3 _SYS from the PSU 16 is at a low level.
- the output terminal of the NOR gate U 2 outputs a low level signal.
- the MOSFET Q 3 is turned off.
- the fan 2 is not operating.
- the system power signal P 3 V 3 _SYS from the PSU 16 is at a high level.
- the NOR gate U 5 outputs a low level signal.
- the MOSFET Q 3 is turned off.
- the fan 2 is powered off.
- 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.
- the speed adjustment module 15 and the temperature measurement module 10 can be omitted.
- the control circuit could activate or deactivate the fan 2 , but not adjust the speed of the fan 2 .
- the BJTs Q 1 and Q 2 , and the MOSFET Q 3 function as electronic switches.
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Computer Hardware Design (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Cooling Or The Like Of Electrical Apparatus (AREA)
- Control Of Positive-Displacement Air Blowers (AREA)
Abstract
Description
- 1. Technical Field
- The present disclosure relates to a circuit for controlling a fan.
- 2. Description of Related Art
- 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.
- 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.
-
FIG. 1 is a block diagram of an exemplary embodiment of a control circuit for a fan. -
FIGS. 2-4 are circuit diagrams of the different components of the control circuit ofFIG. 1 . - 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.
-
FIG. 1 shows an embodiment of a control circuit. The control circuit is to control afan 2 for cooling an integrated baseboard management controller (iBMC) 1 in aserver 100. The control circuit includes atemperature measurement module 10, astate determination module 12, and aspeed adjustment module 15. - The
state determination module 12 is connected to the iBMC 1 and a power supply unit (PSU) 16 of theserver 100, to determine states of the iBMC 1 and theserver 100, and outputs corresponding determination signals. Thestate determination module 12 further supplies power to thefan 2 as needed according to the determination result. Thestate determination module 12 is further connected to thetemperature measurement module 10 and thespeed adjustment module 15. Thestate determination module 12 further supplies power to thetemperature measurement module 10 and thespeed adjustment module 15 as needed according to the determination result. - The
temperature determination module 10 is to measure ambient temperature in the vicinity of the iBMC 1. Thetemperature determination module 10 outputs corresponding pulse-width modulation (PWM) signals to thespeed adjustment module 15 for controlling thefan 2. In the embodiment, thePSU 16 supplies a standby power signal P3V3_STBY. - Referring to
FIG. 2 , thestate 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 thePSU 16 for receiving a system power signal P3V3_SYS from thePSU 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 thefan 2 and thetemperature 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. - Referring to
FIG. 3 , thespeed 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 thetemperature 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 thefan 2. A power pin VCC of thefan 2 is connected to the drain of the MOSFET Q3 for receiving the power signal P3V3_S1. A ground pin GND of thefan 2 is grounded. Speed pins TACH1 and TACH2 of thefan 2 are connected to thetemperature measurement module 10. - Referring to
FIG. 4 , thetemperature 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. - 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 thefan 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. - When the
server 100 is operating, the system power signal P3V3_SYS from thePSU 16 is at a high level. When theserver 100 is powered off, the system power signal P3V3_SYS from thePSU 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 theiBMC 1 is powered off, the state signal BMC_WORK_OK from theiBMC 1 is at a high level. - In the embodiment, the temperature sensor U1 is located near the
iBMC 1 for measuring a temperature of theiBMC 1. - When the
server 100 is powered off and theiBMC 1 is operating, the state signal BMC_WORK_OK from theiBMC 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 thetemperature measurement module 10 and thefan 2 through the MOSFET Q3. Thetemperature measurement module 10 measures the temperature of theiBMC 1, and outputs corresponding PWM signals, according to the temperature, to thespeed adjustment module 15. Thespeed adjustment module 15 controls thefan 2 according to the PWM signals. In addition, a speed of thefan 2 is fedback to the temperature sensor U1 through the speed pins TACH1 and TACH2 of thefan 2. The temperature sensor U1 adjusts thefan 2 accordingly. - When the
server 100 and the iBMC are powered off, the state signal BMC_WORK_OK from theiBMC 1 is at a high level, and the system power signal P3V3_SYS from thePSU 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. Thefan 2 is not operating. - When the
server 100 is operating, the system power signal P3V3_SYS from thePSU 16 is at a high level. In this state, whether theiBMC 1 is operating or powered off, the NOR gate U5 outputs a low level signal. The MOSFET Q3 is turned off. Thefan 2 is powered off. Under these circumstances, theserver 100 is operating, and a system fan (not shown) of theserver 100 is operating, so theiBMC 1 can be cooled by airflow from the system fan of theserver 100. Thefan 2 is powered off to save power. - In other embodiments, if the refinement of speed control is not needed, the
speed adjustment module 15 and thetemperature measurement module 10 can be omitted. In other words, the control circuit could activate or deactivate thefan 2, but not adjust the speed of thefan 2. In addition, the BJTs Q1 and Q2, and the MOSFET Q3 function as electronic switches. - 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.
Claims (8)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201210485632.2 | 2012-11-26 | ||
CN201210485632.2A CN103835978B (en) | 2012-11-26 | 2012-11-26 | Fan control circuitry |
Publications (1)
Publication Number | Publication Date |
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US20140147289A1 true US20140147289A1 (en) | 2014-05-29 |
Family
ID=50773464
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/707,672 Abandoned US20140147289A1 (en) | 2012-11-26 | 2012-12-07 | Fan control circuit |
Country Status (3)
Country | Link |
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US (1) | US20140147289A1 (en) |
CN (1) | CN103835978B (en) |
TW (1) | TW201422921A (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
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US20170027080A1 (en) * | 2015-07-21 | 2017-01-26 | Hong Fu Jin Precision Industry (Shenzhen) Co., Ltd | Control circuit for fan |
US11395443B2 (en) | 2020-05-11 | 2022-07-19 | Coolit Systems, Inc. | Liquid pumping units, and related systems and methods |
US11452243B2 (en) | 2017-10-12 | 2022-09-20 | Coolit Systems, Inc. | Cooling system, controllers and methods |
US11473860B2 (en) * | 2019-04-25 | 2022-10-18 | Coolit Systems, Inc. | Cooling module with leak detector and related systems |
US11661936B2 (en) * | 2013-03-15 | 2023-05-30 | Coolit Systems, Inc. | Sensors, multiplexed communication techniques, and related systems |
US11662037B2 (en) | 2019-01-18 | 2023-05-30 | Coolit Systems, Inc. | Fluid flow control valve for fluid flow systems, and methods |
US11714432B2 (en) * | 2011-08-11 | 2023-08-01 | Coolit Systems, Inc. | Flow-path controllers and related systems |
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CN104454612B (en) * | 2014-12-05 | 2016-08-24 | 深圳市创荣发电子有限公司 | One is capable of thermoregulator fan remote controller |
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US10712795B2 (en) * | 2018-01-30 | 2020-07-14 | Quanta Computer Inc. | Power supply unit fan recovery process |
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CN111090319B (en) * | 2019-11-21 | 2021-07-30 | 苏州浪潮智能科技有限公司 | Method, device and medium for controlling server fan based on thermistor |
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CN113900501B (en) * | 2021-09-30 | 2023-07-14 | 苏州浪潮智能科技有限公司 | Cooling system for server and server |
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Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7990087B2 (en) * | 2008-10-21 | 2011-08-02 | Dell Products, Lp | System and method for providing cooling fan characteristic feedback |
US20130073096A1 (en) * | 2011-09-16 | 2013-03-21 | International Business Machines Corporation | Proactive cooling control using power consumption trend analysis |
US8489250B2 (en) * | 2009-09-30 | 2013-07-16 | International Business Machines Corporation | Fan control system and method for a computer system |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR100260380B1 (en) * | 1996-01-26 | 2000-07-01 | 윤종용 | System & method of controlling fan for micro processor chip |
US20080285461A1 (en) * | 2007-05-15 | 2008-11-20 | Inventec Corporation | Method for remotely monitoring system |
CN201075819Y (en) * | 2007-07-09 | 2008-06-18 | 台达电子工业股份有限公司 | Fan system and soft start circuit module thereof |
CN102253881A (en) * | 2010-05-20 | 2011-11-23 | 英业达科技有限公司 | Server operating state detection system |
CN102445977A (en) * | 2010-09-30 | 2012-05-09 | 鸿富锦精密工业(深圳)有限公司 | System and method for lowering startup peak current of server |
-
2012
- 2012-11-26 CN CN201210485632.2A patent/CN103835978B/en not_active Expired - Fee Related
- 2012-11-28 TW TW101144614A patent/TW201422921A/en unknown
- 2012-12-07 US US13/707,672 patent/US20140147289A1/en not_active Abandoned
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7990087B2 (en) * | 2008-10-21 | 2011-08-02 | Dell Products, Lp | System and method for providing cooling fan characteristic feedback |
US8489250B2 (en) * | 2009-09-30 | 2013-07-16 | International Business Machines Corporation | Fan control system and method for a computer system |
US20130073096A1 (en) * | 2011-09-16 | 2013-03-21 | International Business Machines Corporation | Proactive cooling control using power consumption trend analysis |
Cited By (9)
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US11714432B2 (en) * | 2011-08-11 | 2023-08-01 | Coolit Systems, Inc. | Flow-path controllers and related systems |
US11661936B2 (en) * | 2013-03-15 | 2023-05-30 | Coolit Systems, Inc. | Sensors, multiplexed communication techniques, and related systems |
US20170027080A1 (en) * | 2015-07-21 | 2017-01-26 | Hong Fu Jin Precision Industry (Shenzhen) Co., Ltd | Control circuit for fan |
US9901006B2 (en) * | 2015-07-21 | 2018-02-20 | Hong Fu Jin Precision Industry (Shenzhen) Co., Ltd. | Control circuit for fan |
US11452243B2 (en) | 2017-10-12 | 2022-09-20 | Coolit Systems, Inc. | Cooling system, controllers and methods |
US11662037B2 (en) | 2019-01-18 | 2023-05-30 | Coolit Systems, Inc. | Fluid flow control valve for fluid flow systems, and methods |
US11473860B2 (en) * | 2019-04-25 | 2022-10-18 | Coolit Systems, Inc. | Cooling module with leak detector and related systems |
US11725890B2 (en) | 2019-04-25 | 2023-08-15 | Coolit Systems, Inc. | Cooling module with leak detector and related systems |
US11395443B2 (en) | 2020-05-11 | 2022-07-19 | Coolit Systems, Inc. | Liquid pumping units, and related systems and methods |
Also Published As
Publication number | Publication date |
---|---|
TW201422921A (en) | 2014-06-16 |
CN103835978A (en) | 2014-06-04 |
CN103835978B (en) | 2016-05-11 |
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Owner name: HONG FU JIN PRECISION INDUSTRY (SHENZHEN) CO., LTD Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:TIAN, BO;WU, KANG;REEL/FRAME:029423/0747 Effective date: 20121203 Owner name: HON HAI PRECISION INDUSTRY CO., LTD., TAIWAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:TIAN, BO;WU, KANG;REEL/FRAME:029423/0747 Effective date: 20121203 |
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