U.S. patent application number 13/325198 was filed with the patent office on 2013-06-20 for performance and noise control for a heat sink air mover.
This patent application is currently assigned to INTERNATIONAL BUSINESS MACHINES CORPORATION. The applicant listed for this patent is Diane S. Busch, Michael S. June, Mark E. Steinke. Invention is credited to Diane S. Busch, Michael S. June, Mark E. Steinke.
Application Number | 20130153199 13/325198 |
Document ID | / |
Family ID | 48608936 |
Filed Date | 2013-06-20 |
United States Patent
Application |
20130153199 |
Kind Code |
A1 |
Busch; Diane S. ; et
al. |
June 20, 2013 |
PERFORMANCE AND NOISE CONTROL FOR A HEAT SINK AIR MOVER
Abstract
A system and method for cooling a heat-generating device. The
system comprises a heat sink base for contacting the
heat-generating device, and a plurality of heat sink fins extending
from the heat sink base, wherein the fins provide airflow passages
that are open along a top, a first side and a second side. An ionic
air moving device is disposed along at least one side of the heat
sink for moving air through the airflow passages, and a fan is
mounted adjacent to the top of the fins for moving air through the
airflow passages. A controller selectively controls the airflow
through the heat sink using only the ionic device, only the fan, or
both the ionic device and the fan. A user or a system component may
instruct the controller to enter a performance mode, an energy
efficiency mode, or an acoustic mode.
Inventors: |
Busch; Diane S.; (Durham,
NC) ; June; Michael S.; (Raleigh, NC) ;
Steinke; Mark E.; (Durham, NC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Busch; Diane S.
June; Michael S.
Steinke; Mark E. |
Durham
Raleigh
Durham |
NC
NC
NC |
US
US
US |
|
|
Assignee: |
INTERNATIONAL BUSINESS MACHINES
CORPORATION
Armonk
NY
|
Family ID: |
48608936 |
Appl. No.: |
13/325198 |
Filed: |
December 14, 2011 |
Current U.S.
Class: |
165/287 |
Current CPC
Class: |
H01L 23/467 20130101;
F28F 2250/00 20130101; H01L 2924/0002 20130101; F28D 2021/0029
20130101; F28F 13/16 20130101; F28F 27/00 20130101; H01L 2924/0002
20130101; H01L 2924/00 20130101 |
Class at
Publication: |
165/287 |
International
Class: |
F28F 27/00 20060101
F28F027/00 |
Claims
1. A system for cooling a heat-generating device, comprising: a
heat sink base for contacting the heat-generating device; a
plurality of heat sink fins extending from the heat sink base,
wherein the fins provide airflow passages that are open along a
top, a first side and a second side; an ionic device disposed along
at least one side of the heat sink for moving air through the
airflow passages; a fan mounted adjacent to the distal end of the
fins for moving air through the airflow passages; and a controller
configured to selectively control the airflow through the heat sink
using only the ionic device, only the fan, or both the ionic device
and the fan.
2. The system of claim 1, wherein the fan is disposed along the top
of the heat sink.
3. The system of claim 2, wherein the fan pushes air into the
airflow passages from the top of the fins and the air exits the
airflow passages at the first and second sides.
4. The system of claim 1, wherein the fan draws the air out of the
airflow passages at the top of the fins and air enters the airflow
passages at the first and second sides.
5. The system of claim 1, further comprising: a temperature sensor
coupled to the heat sink base, wherein the temperature sensor
provides a temperature signal to the controller.
6. The system of claim 5, wherein the controller includes a control
circuit dedicated to the operation of the fan and ionic device.
7. The system of claim 1, wherein the heat-generating device is a
processor.
8. The system of claim 7, wherein the processor and the heat sink
are provided on an expansion card.
9. The system of claim 7, wherein the controller is a service
processor in communication with the processor.
10. The system of claim 9, wherein the service processor is
selected from a baseboard management processor and an integrated
management module.
11. A method of cooling a heat-generating device, comprising:
inducing airflow through a heat sink from a first side of the heat
sink to a second side of the heat sink using an ionic device,
wherein the heat sink has a base in thermal communication with the
heat-generating device and a plurality of heat sink fins extending
from the heat sink base, wherein the fins provide airflow passages
that are open along a top and between the first and second sides;
inducing airflow through the top of the heat sink using a fan; and
selectively controlling the airflow using only the ionic device,
only the fan, or both the ionic device and the fan.
12. The method of claim 11, further comprising: in response to
input received from a user or system controller selecting a
performance mode, inducing airflow through the heat sink using only
the fan.
13. The method of claim 11, further comprising: in response to
input received from a user or system controller selecting an energy
efficiency mode, inducing airflow through the heat sink using the
ionic device up to a setpoint condition and using the fan above the
setpoint condition.
14. The method of claim 13, wherein the setpoint condition is
selected from a temperature setpoint, an energy setpoint, or a
combination thereof.
15. The method of claim 14, wherein the heat generating device is a
processor, the temperature setpoint is a processor temperature
setpoint, and the energy setpoint is a processor energy consumption
setpoint.
16. The method of claim 11, further comprising: in response to
input received from a user or system controller selecting an
acoustic mode, inducing airflow through the heat sink using only
the ionic device.
17. The method of claim 16, wherein the heat-generating device is a
processor.
18. The method of claim 17, further comprising: in response to the
processor reaching a temperature exceeding a processor temperature
setpoint while in the acoustic mode, continuing to induce airflow
through the heat sink using only the ionic device and throttling a
processor speed.
19. The method of claim 11, wherein the fan induces airflow into
the heat sink through the top of the heat sink and out the first
and second sides of the heat sink.
20. The method of claim 11, wherein the fan induces airflow into
the heat sink through the first and second sides of the heat sink
and out the top of the heat sink.
Description
BACKGROUND
[0001] 1. Field of the Invention
[0002] The present invention relates to heat sinks having an air
mover, and methods of controlling the air mover of a heat sink.
[0003] 2. Background of the Related Art
[0004] Computer systems include numerous components that use
electrical energy and produce heat as a byproduct. Typically, these
components are organized in a housing or chassis for efficient
placement, storage and operation. In large computer systems, these
individual chassis may be further organized into a rack-based
computer system that enables many rack-mounted components to be
operated in a high-density arrangement, which can produce a
considerable amount of heat. However, each individual chassis may
have its own unique cooling requirements that may change over time
with varying workload.
[0005] Heat produced by the components within the chassis must be
removed to control internal component temperatures and to maintain
system reliability, performance, and longevity. In a conventional
rack-based computer system, rack-mounted fans move cool air through
the rack to cool the components. Standalone chassis may have their
own dedicated fans. However, air moving through the chassis will
tend to take the path of least resistance and it becomes necessary
to consider air flow impedance between and among components and
groups of components within a chassis. In order to achieve adequate
airflow to each component without excessive operation of the fans,
system designers will position and orient components within the
chassis with due consideration to the need for adequate
airflow.
[0006] A processor can produce a great deal of heat during heavy
usage and is typically secured to a motherboard in direct thermal
communication with large heat sink. The heat sink fins extend away
from the motherboard into the path of airflow through the chassis
and generally comprise a group of fins that are oriented parallel
to the airflow direction. Similarly, a chassis may also support
multiple memory modules that are commonly arranged together on a
motherboard and oriented parallel to the airflow direction through
the chassis. However, each and every processor, memory module, and
other component within the chassis need adequate airflow.
[0007] In any given chassis design, the component layout and
operation may be tested to assure adequate airflow to each
component. Still, there is a desire to avoid excessive use of fans,
since fan operation can consume significant power and produce
significant noise. It is desirable, therefore, to use airflow
efficiently and effectively. This objective is complicated by the
dynamic nature of workloads, and thus heat production, among the
chassis components.
BRIEF SUMMARY
[0008] One embodiment of the invention provides a system for
cooling a heat-generating device. The system comprises a heat sink
base for contacting the heat-generating device, and a plurality of
heat sink fins extending from the heat sink base, wherein the fins
provide airflow passages that are open along a top, a first side
and a second side. An ionic device is disposed along at least one
side of the heat sink for moving air through the airflow passages,
and a fan is mounted adjacent to the top of the fins for moving air
through the airflow passages. A controller is configured to
selectively control the airflow through the heat sink using only
the ionic device, only the fan, or both the ionic device and the
fan.
[0009] Another embodiment of the present invention provides a
method of cooling a heat-generating device. The method comprises
inducing airflow through a heat sink from a first side of the heat
sink to a second side of the heat sink using an ionic device,
wherein the heat sink has a base in thermal communication with the
heat-generating device and a plurality of heat sink fins extending
from the heat sink base, wherein the fins provide airflow passages
that are open along a top and between the first and second sides.
The method further comprises inducing airflow through the top of
the heat sink using a fan. Still further, the method selectively
controls the airflow using only the ionic device, only the fan, or
both the ionic device and the fan.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0010] FIG. 1 is an exploded perspective view of a heat sink with a
fan and an ionic air moving device.
[0011] FIG. 2 is a perspective view of the heat sink with the fan
and the ionic air moving device secured to the heat sink.
[0012] FIG. 3 is a top view of the heat sink with the fan removed
to show the positioning of an array of emitter electrodes along a
first end of the heat sink.
[0013] FIG. 4 is a top view of the cut-out region of FIG. 3 showing
the positioning of each emitter electrode with respect to the heat
sink fins.
[0014] FIG. 5 is a block diagram of a system for cooling a
processor in accordance with one embodiment of the invention.
[0015] FIGS. 6A-6C are block diagrams of alternative configurations
of a cooling system including a heat sink, a fan, and at least one
set of emitter electrodes.
[0016] FIGS. 7A-7B are block diagrams of cooling systems that
include ionic air moving devices that have an independent set of
collector electrodes, rather than using the heat sink fins as the
collector electrodes.
DETAILED DESCRIPTION
[0017] One embodiment of the present invention provides a system
for cooling a heat-generating device. The system comprises a heat
sink base for contacting the heat-generating device, and a
plurality of heat sink fins extending from the heat sink base,
wherein the fins provide airflow passages that are open along a
top, a first side and a second side. An ionic air moving device is
disposed along at least one side of the heat sink for moving air
through the airflow passages, and a fan is mounted adjacent to the
top of the fins for moving air through the airflow passages. A
controller is configured to selectively control the airflow through
the heat sink using only the ionic air moving device, only the fan,
or both the ionic air moving device and the fan.
[0018] While advances have been made in the amount of power that
can be cooled using an ionic air moving device, the present systems
and methods augment the ionic air moving device with one or more
conventional air moving devices, such as a fan, for the higher
power applications. A top mounted impingement fan allows for
unrestricted side to side and/or front to back airflow through the
heat sink provided by the ionic devices. The ionic device are thus
able provide the airflow sufficient to cool a heat-generating
device up to certain limits. For example, where the heat-generating
device is a processor, the ionic air moving device may provide
sufficient airflow to cool the processor until the processor power
consumption is about 70 W. Above about 70 W power consumption, the
fan can replace or augment this airflow at higher rates of
airflow.
[0019] The heat sink includes either fins, pins or other structures
having a high surface area for transferring heat into air that is
made to flow over the surfaces. Furthermore, the fins, pins or
other structures generally extend from the heat sink base, which
contacts, or is otherwise in thermal communication with, a heat
generating components. The fins, pins or other structures may be
supplemented with heat spreaders or heat pipes.
[0020] In preferred embodiments, the fan is an impingement fan
disposed along the top of the heat sink. In a first configuration,
the fan pushes air into the airflow passages from the top of the
fins and the air exits the airflow passages at the first and second
sides. In a second configuration, the fan draws the air out of the
airflow passages at the top of the fins and air enters the airflow
passages at the first and second sides.
[0021] In one embodiment, the system further comprises a
temperature sensor that is coupled to the heat sink base. The
temperature sensor provides a temperature signal to the controller
for use in controlling the operation of the ionic device and the
fan. Optionally, the controller may be implemented as a control
circuit that is dedicated to the operation of the fan and ionic
device. Such an embodiment is mostly self-contained and only
requires an external source of electrical power.
[0022] In certain embodiments, the heat-generating device is a
processor. For example, the processor and the heat sink may be
provided on an expansion card. Alternatively, the processor may be
installed on a motherboard and the controller is a service
processor for the motherboard. In the later alternative, the
service processor may be, without limitation, selected from a
baseboard management processor and an integrated management
module.
[0023] The ionic air moving device may be configured to induce
airflow through the plurality of airflow passages in the heat sink.
For example, the ionic air moving device may comprise a plurality
of electrode pairs, where each electrode pair includes an ion
emitter electrode disposed a spaced distance upstream in the
airflow direction from a collector electrode. The emitter electrode
and the collector electrode are coupled to a power source for
applying an electrical potential between the emitter electrode and
the collector electrode. The controller may control the electrical
potential between the emitter and collector electrode of each
electrode pair to affect the desired rate of airflow and cooling. A
couple of primary advantages of using an ionic air moving device
are that it operates silently and has no moving parts.
[0024] In one embodiment, the plurality of electrode pairs are
aligned with the airflow passages through the heat sink. In one
configuration, the emitter electrode may be a thin wire, and the
ion collector electrode may be a portion of the heat sink fins. In
an alternative configuration, the emitter electrode may be a
needle. A high electric potential, such as 8000V DC or greater, is
applied across the two electrodes leading to ionization of air
around the wires. The ions are then attracted to the ion collector
electrode and, in the process, transfer momentum to the adjacent
air molecules resulting in airflow in a direction from the emitter
electrode to the collector electrode.
[0025] Where a nonionic air moving device has already established
an airflow rate through the chassis in an airflow direction, the
ionic movement of air may serve to enhance the airflow rate so long
as the ion emitter electrode is upstream of the collector electrode
(to cause airflow enhancement or reduce airflow impedance). It
should be recognized that all references to upstream or downstream
positions are made with reference to the desired airflow direction.
It is also within the scope of the invention to provide more than
one ionic air moving device, such as one ionic air moving device at
each end of the heat sink to force air inwardly from each end and
out through the top of the heat sink. Accordingly, if the fan is
mounted to the top of the heat sink and directed to draw air out of
the heat sink air passages, then the fan and the ionic air moving
devices may induce airflow in the same direction. In another
alternative, an ionic air moving device could be positioned at one
end and the fan could be positioned at the same end or the opposite
end to direct airflow in the same direction as the ionic air moving
device.
[0026] More generally, ionic air moving devices for use in the
present invention may comprise a high curvature electrode for
emitting ions, such as the tip of a needle or a thin wire, and a
blunt electrode for collecting ions, such as a plate or a ring.
Although the electrical potential is preferably 8000V DC or
greater, the power input to the ionic device may be less than 20 W
with the proper optimization.
[0027] Another embodiment of the present invention provides a
method of cooling a heat-generating device. The method comprises
inducing airflow through a heat sink from a first side of the heat
sink to a second side of the heat sink using an ionic device,
wherein the heat sink has a base in thermal communication with the
heat-generating device and a plurality of heat sink fins extending
from the heat sink base, wherein the fins provide airflow passages
that are open along a top and between the first and second sides.
The method further comprises inducing airflow through the top of
the heat sink using a fan. Still further, the method selectively
controls the airflow using only the ionic device, only the fan, or
both the ionic device and the fan.
[0028] Certain optional embodiments of the method may include two
or more modes of operating the air movers (i.e., the ionic device
and the fan). For example, the controller may operate the air
movers in a performance mode, an energy efficiency mode or an
acoustic mode. While the controller will operate the air movers in
only one mode at a time, the controller may be placed in two or
more of these modes at different times in accordance with input
received from a user or another system component or controller,
such as a service processor.
[0029] For example, in response to input received from a user or
system controller selecting a performance mode, the controller
induces airflow through the heat sink using only the fan. In
performance mode, it is the performance of the heat-generating
device that is given the greatest priority. The fan is able to
produce higher airflow rates than the ionic air moving device, so
the fan is used to control the temperature of the heat-generating
despite a high level of performance. Where the heat-generating
device is a processor, a high level of performance may be a high
workload or high processor speeds that result in greater heat
generation. The high volume of airflow induced by the fan allows
the processor to continue operation at these high levels of
performance without the need to throttle the processor.
[0030] In response to input received from a user or system
controller selecting an energy efficiency mode, the controller
induces airflow through the heat sink using the ionic device up to
a setpoint condition and using the fan above the setpoint
condition. Optionally, the setpoint condition is selected from a
temperature setpoint, an energy setpoint, or a combination thereof.
When the heat generating device is a processor, the temperature
setpoint may be a processor temperature setpoint, and the energy
setpoint may be a processor energy consumption setpoint. In
accordance with the energy efficiency mode, the system starts out
using only the ionic air moving device in order to get the best
cooling efficiency. If the workload of the CPU is fluctuates or
increases, then the fan can be triggered by a temperature or energy
threshold to augment the cooling.
[0031] In response to input received from a user or system
controller selecting an acoustic mode, the controller induces
airflow through the heat sink using only the ionic device. It
should be recognized that if the heat-generating device produces
enough heat, as with a processor under a heavy workload, then the
maximum airflow capacity of the ionic device may be insufficient to
cool the heat-generating device. However, in the acoustic mode, in
response to the processor reaching a temperature exceeding a
processor temperature setpoint, airflow through the heat sink
continues to be provided only by the ionic device, even if this
results in throttling a processor speed. The use of only the ionic
air moving device maintains silent operation to minimize acoustic
levels.
[0032] FIG. 1 is an exploded perspective view of a cooling system
10 including a heat sink 20 with a fan 30 and an ionic air moving
device 40. The heat sink 20 is shown as a conventional heat sink
having a base 22 and a plurality of fins 24. The base 22 is secured
in thermal communication with a heat-generating device (not shown),
and the plurality of fins 24 forms a plurality of airflow passages
therebetween. Specifically, the heat sink 20 has ten (10) fins 24
and forms nine (9) airflow passages that are open along the top 26
and open at a first end 27 and a second end 28. The fan 30 is
secured over the top 26 of the heat sink fins 24 and may be
directed to blow air upward or downward. A frame 42 secures a
plurality of emitter electrodes 44 and couples them to a negative
(-) terminal of a voltage source. The heat sink 20 is coupled to a
positive (+) terminal of a voltage source, such that the individual
fins 24 serve as collector electrodes. The electrical potential
applied between the emitter electrodes 44 and the fins 24 cause a
flow of ions from the emitter electrodes 44 to the fins 24. The
flow of ions causes a flow of air in the same direction.
Preferably, the frame 42 and the emitter electrodes 44 are secured
along one of the open sides 27 of the heat sink 20 to induce
airflow through the plurality of air passages between the plurality
of fins. Accordingly, the ionic air moving device 40 generates
airflow from the first side 27 to the second side 28 of the heat
sink.
[0033] FIG. 2 is a perspective view of the cooling system 10 with
the fan 30 secured to the top 26 of the heat sink 20 and the frame
42 secured to the first side 27 of the heat sink 20. The system 10
is shown with the fan 30 operating to draw air out through the top
26 of the heat sink 20 from the plurality of air passages. The
airflow flows into the open first side 27 and the open second side
28, then across the surfaces of the fins 24 absorbing heat before
being exhausted from the heat sink 20 through the fan 30. Although
the emitter electrodes 44 are shown in their operable position, the
emitter electrodes are not being used in FIG. 2 to induce airflow.
The emitter electrodes are made from thin wire and do not cause any
appreciable resistance to the airflow generated by the fan 30. More
about the operation of the ionic air moving device 40 will be
discussed in regard to FIG. 3.
[0034] FIG. 3 is a top view of the heat sink 10 with the fan
removed to show the positioning of an array of emitter electrodes
44 in a frame 42 along the first end 27 of the heat sink 20. The
emitter electrodes 44 are electrically coupled to a negative
terminal of a power supply/voltage regulator, and the heat sink
fins 24 are electronically coupled to a positive terminal of the
power supply/voltage regulator. As shown, the emitter electrodes 44
are in the form of wires that run parallel to the leading edge of
the fins 24. The emitter electrodes 44 are shown centered between a
pair of adjacent fins, but may be aligned with the fins or
otherwise positioned. A cut-out region of FIG. 3 is shown in
greater detail in FIG. 4.
[0035] FIG. 4 is a top view of the cut-out region of FIG. 3 showing
the positioning of each emitter electrode 44 with respect to a
leading edge 29 of the heat sink fins 24. The frame 42 secures the
wires that form the emitter electrodes 44 in a spaced-apart
relationship to each other. Preferably, the pitch between adjacent
emitter electrodes 44 (distance X) is the same as the pitch between
adjacent fins 24 (also distance X). The frame 42 may also be used
to establish a spaced-apart relationship between the emitter
electrodes 44 and the first end 27 of the heatsink 20 (distance Y).
The wavy arrows in FIG. 4 indicate the airflow generated by use of
the ionic air moving device 40.
[0036] As shown, the emitter electrodes 44 have a negative charge
that allows negatively charged ions to form. The electrical
potential between the emitter electrodes 44 and the fins 24 induces
the ions to move through air from the emitter electrodes 44 to the
fins 24, which form the collector electrodes. This movement of ions
(shown by wavy arrows in FIG. 4) drags air with it to cause airflow
into the open first end 27 of the heatsink and out the open second
end 28 (See FIG. 3) of the heat sink.
[0037] FIG. 5 is a block diagram of a system 50 for cooling a
processor 52 in accordance with one embodiment of the invention.
The system 50 includes the system 10 of FIGS. 1 through 4, which
comprises the heat sink 20, the fan 30, and the emitter electrodes
44. The base of the heatsink 20 is in thermal communication with
the processor 52 to conduct heat away from the processor to the
plurality of heat sink fins.
[0038] A controller 54 receives a temperature signal from a
temperature sensor 56 that measures, in various embodiments, either
the temperature of the heatsink base, the temperature of the
processor 52, or the temperature of some related component.
Accordingly, the temperature sensor 56 may be coupled to the heat
sink or the processor, but may also be a temperature sensor that is
an internal element of the processor. Where the temperature sensor
is coupled directly to the heat sink, the temperature signal may be
communicated to the control as an analog signal requiring an
analog-to-digital conversion. Where the temperature sensor is
internal to the processor, the temperature signal produced by the
processor will already be a digital signal that may be
communicated, for example, via a communications bus with the
controller. Where the controller 54 is a baseboard management
controller (BMC) or an integrated management module (IMM), the
communications bus may be an inter-integrated circuit (I2C)
bus.
[0039] The controller 54 is in electronic communication with both
the fan 30 and the ionic air moving device 40 and controls the
operation of both devices. As for the ionic air moving device 40,
the controller 54 may provide a control signal to a power
supply/voltage regulator 58 to turn the device 40 on or off, or
perhaps also indicate a desired voltage to be applied between the
positive and negative terminals of the regulator 58. Because the
emitter electrodes 44 are coupled to the negative terminal and the
fins of the heat sink 20 are coupled to the positive terminal, the
electrical potential causes a flow of ions that lead to airflow
through the heat sink 20.
[0040] The controller 54 receives input from either a user
interface 60 or another system component 62, such as a remote
management module or system that manages the energy and acoustic
policies for a datacenter. As described herein, the controller 54
may establish a plurality of operating modes, such as a performance
mode, an energy efficiency mode, and an acoustic mode. For example,
in response to input received from the user interface or other
system component selecting the performance mode, the controller
induces airflow through the heat sink using only the fan. In
response to input received from the user interface or other system
component selecting an energy efficiency mode, the controller
induces airflow through the heat sink using the ionic device up to
a setpoint condition and using the fan above the setpoint
condition. Optionally, the setpoint condition is selected from a
temperature setpoint, an energy setpoint, or a combination thereof.
When the heat generating device is a processor, the temperature
setpoint may be a processor temperature setpoint, and the energy
setpoint may be a processor energy consumption setpoint. In
accordance with the energy efficiency mode, the system starts out
using only the ionic air moving device in order to get the best
cooling efficiency. If the workload of the CPU is fluctuates or
increases, then the fan can be triggered by a temperature or energy
threshold to augment the cooling. In response to input received
from the user interface or other system component selecting an
acoustic mode, the controller induces airflow through the heat sink
using only the ionic device. It should be recognized that if the
heat-generating device produces enough heat, as with a processor
under a heavy workload, then the maximum airflow capacity of the
ionic device may be insufficient to cool the heat-generating
device. However, in the acoustic mode, in response to the processor
reaching a temperature exceeding a processor temperature setpoint,
airflow through the heat sink continues to be provided only by the
ionic device, even if this results in throttling a processor speed.
The use of only the ionic air moving device maintains silent
operation to minimize acoustic levels.
[0041] FIGS. 6A-6C are block diagrams of alternative configurations
of a cooling system including a heat sink 20, a fan 30, and at
least one set of emitter electrodes 44. In FIG. 6A, a fan 30 is
positioned at the same end of the heat sink 20 as a set of emitter
electrodes 44, preferably with the fan directing airflow in the
same direction as the ionic air moving device, which includes the
emitter electrodes and the heat sink. FIG. 6B is similar to FIG.
6A, except that the fan 30 is positioned on the opposite end of the
heat sink 20 from the emitter electrodes 44. Still, it is
preferable that the fan direct airflow in the same direction as the
ionic air moving device formed by the emitter electrodes and the
heat sink. In FIG. 6C, a set of emitter electrodes 44 is positioned
at each end of the heat sink 20 to force air inwardly from each end
and out through the top of the heat sink. The fan 30 is mounted to
the top of the heat sink and is directed to draw air out of the
heat sink air passages. Accordingly, the fan induces airflow in the
same general direction or path as the two ionic air moving
devices.
[0042] FIGS. 7A-7B are block diagrams showing further embodiments
in which the ionic air moving device includes an independent set of
collector electrodes 70, rather than using the heat sink fins as
the collector electrodes. The ionically induced airflow still flows
from emitter electrodes 44 to collector electrodes 70, such that
airflow can be induced through the heat sink 20. The dashed boxes
represent the alternative placements of a fan. In FIG. 7A, the
arrangement of the emitter electrodes 44 and collector electrodes
70 causes airflow that is directed into one end of the heat sink
20. By contrast, the arrangement of the emitter electrodes 44 and
collector electrodes 70 in FIG. 7B allows the ionic air moving
device to draw airflow out of the end of the heat sink 20. It
should be recognized that any of the embodiments described above
may utilize collector electrodes that are separate from the heat
sink to achieve the same general airflow as described in relation
to those embodiments where the heat sink fins served as the
collector electrodes.
[0043] As will be appreciated by one skilled in the art, aspects of
the present invention may be embodied as a system, method or
computer program product. Accordingly, aspects of the present
invention may take the form of an entirely hardware embodiment, an
entirely software embodiment (including firmware, resident
software, micro-code, etc.) or an embodiment combining software and
hardware aspects that may all generally be referred to herein as a
"circuit," "module" or "system." Furthermore, aspects of the
present invention may take the form of a computer program product
embodied in one or more computer readable medium(s) having computer
readable program code embodied thereon.
[0044] Any combination of one or more computer readable medium(s)
may be utilized. The computer readable medium may be a computer
readable signal medium or a computer readable storage medium. A
computer readable storage medium may be, for example, but not
limited to, an electronic, magnetic, optical, electromagnetic,
infrared, or semiconductor system, apparatus, or device, or any
suitable combination of the foregoing. More specific examples (a
non-exhaustive list) of the computer readable storage medium would
include the following: an electrical connection having one or more
wires, a portable computer diskette, a hard disk, a random access
memory (RAM), a read-only memory (ROM), an erasable programmable
read-only memory (EPROM or Flash memory), an optical fiber, a
portable compact disc read-only memory (CD-ROM), an optical storage
device, a magnetic storage device, or any suitable combination of
the foregoing. In the context of this document, a computer readable
storage medium may be any tangible medium that can contain, or
store a program for use by or in connection with an instruction
execution system, apparatus, or device.
[0045] A computer readable signal medium may include a propagated
data signal with computer readable program code embodied therein,
for example, in baseband or as part of a carrier wave. Such a
propagated signal may take any of a variety of forms, including,
but not limited to, electro-magnetic, optical, or any suitable
combination thereof. A computer readable signal medium may be any
computer readable medium that is not a computer readable storage
medium and that can communicate, propagate, or transport a program
for use by or in connection with an instruction execution system,
apparatus, or device.
[0046] Program code embodied on a computer readable medium may be
transmitted using any appropriate medium, including but not limited
to wireless, wireline, optical fiber cable, RF, etc., or any
suitable combination of the foregoing.
[0047] Computer program code for carrying out operations for
aspects of the present invention may be written in any combination
of one or more programming languages, including an object oriented
programming language such as Java, Smalltalk, C++ or the like and
conventional procedural programming languages, such as the "C"
programming language or similar programming languages. The program
code may execute entirely on the user's computer, partly on the
user's computer, as a stand-alone software package, partly on the
user's computer and partly on a remote computer or entirely on the
remote computer or server. In the latter scenario, the remote
computer may be connected to the user's computer through any type
of network, including a local area network (LAN) or a wide area
network (WAN), or the connection may be made to an external
computer (for example, through the Internet using an Internet
Service Provider).
[0048] Aspects of the present invention are described herein with
reference to flowchart illustrations and/or block diagrams of
methods, apparatus (systems) and computer program products
according to embodiments of the invention. It will be understood
that each block of the flowchart illustrations and/or block
diagrams, and combinations of blocks in the flowchart illustrations
and/or block diagrams, can be implemented by computer program
instructions. These computer program instructions may be provided
to a processor of a general purpose computer, special purpose
computer, or other programmable data processing apparatus to
produce a machine, such that the instructions, which execute via
the processor of the computer or other programmable data processing
apparatus, create means for implementing the functions/acts
specified in the flowchart and/or block diagram block or
blocks.
[0049] These computer program instructions may also be stored in a
computer readable medium that can direct a computer, other
programmable data processing apparatus, or other devices to
function in a particular manner, such that the instructions stored
in the computer readable medium produce an article of manufacture
including instructions which implement the function/act specified
in the flowchart and/or block diagram block or blocks.
[0050] The computer program instructions may also be loaded onto a
computer, other programmable data processing apparatus, or other
devices to cause a series of operational steps to be performed on
the computer, other programmable apparatus or other devices to
produce a computer implemented process such that the instructions
which execute on the computer or other programmable apparatus
provide processes for implementing the functions/acts specified in
the flowchart and/or block diagram block or blocks.
[0051] The flowchart and block diagrams in the Figures illustrate
the architecture, functionality, and operation of possible
implementations of systems, methods and computer program products
according to various embodiments of the present invention. In this
regard, each block in the flowchart or block diagrams may represent
a module, segment, or portion of code, which comprises one or more
executable instructions for implementing the specified logical
function(s). It should also be noted that, in some alternative
implementations, the functions noted in the block may occur out of
the order noted in the figures. For example, two blocks shown in
succession may, in fact, be executed substantially concurrently, or
the blocks may sometimes be executed in the reverse order,
depending upon the functionality involved. It will also be noted
that each block of the block diagrams and/or flowchart
illustration, and combinations of blocks in the block diagrams
and/or flowchart illustration, can be implemented by special
purpose hardware-based systems that perform the specified functions
or acts, or combinations of special purpose hardware and computer
instructions.
[0052] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the invention. As used herein, the singular forms "a", "an" and
"the" are intended to include the plural forms as well, unless the
context clearly indicates otherwise. It will be further understood
that the terms "comprises" and/or "comprising," when used in this
specification, specify the presence of stated features, integers,
steps, operations, elements, components and/or groups, but do not
preclude the presence or addition of one or more other features,
integers, steps, operations, elements, components, and/or groups
thereof. The terms "preferably," "preferred," "prefer,"
"optionally," "may," and similar terms are used to indicate that an
item, condition or step being referred to is an optional (not
required) feature of the invention.
[0053] The corresponding structures, materials, acts, and
equivalents of all means or steps plus function elements in the
claims below are intended to include any structure, material, or
act for performing the function in combination with other claimed
elements as specifically claimed. The description of the present
invention has been presented for purposes of illustration and
description, but it is not intended to be exhaustive or limited to
the invention in the form disclosed. Many modifications and
variations will be apparent to those of ordinary skill in the art
without departing from the scope and spirit of the invention. The
embodiment was chosen and described in order to best explain the
principles of the invention and the practical application, and to
enable others of ordinary skill in the art to understand the
invention for various embodiments with various modifications as are
suited to the particular use contemplated.
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