Note: Descriptions are shown in the official language in which they were submitted.
UN10006
LIGHT EMITTING DIODE COOLING SYSTEMS AND METHODS
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from and the benefit of U.S.
Provisional Patent
Application Serial No. 62/854,161, entitled "LIGHT EMITTING DIODE COOLING
SYSTEMS AND METHODS", filed May 29, 2019, which is hereby incorporated by
reference.
BACKGROUND
100021 The present disclosure relates generally to light cooling systems.
10003] This section is intended to introduce the reader to various aspects of
art that may be
related to various aspects of the present techniques, which are described
and/or claimed
below. This discussion is believed to be helpful in providing the reader with
background
information to facilitate a better understanding of the various aspects of the
present
disclosure. Accordingly, it should be understood that these statements are to
be read in this
light, and not as admissions of prior art.
[0004] Generally, LED lighting instruments provide lighting for a variety of
applications.
In some applications, high intensity lighting from LED lighting instruments
may be
desirable. For example, LED lighting instruments may provide high intensity
lighting for
motion picture and television sets and studios. To provide such high intensity
lighting
(e.g., lighting consuming 500W-1500W of total power), an arrangement of LEDs
within
the lighting instruments may be relatively dense and numerous. As the density
of LEDs in
a given space increase, an amount of heat produced by the LEDs and a
temperature of the
LEDs may generally increase. Typical Wall Plug Efficiency ("WPE") of blue LEDs
used
to make white light is 50% such that only 50% of the energy will be converted
into photons
and the other 50% will be lost as heat. There may be an additional loss when
the light is
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converted from blue light to white by the phosphors. As such, about half of
the electrical
power provided to LEDs is converted into heat.
[0005] Conventional cooling techniques for lighting systems may not
sufficiently cool
such high intensity LED lighting instruments. Additionally, Chip Scale
Packaging ("CSP")
technology and Chip on Board ("COB") arrays provide the ability to directly
attach LED
die to a printed circuit board ("PCB") without a package. Typical LED die are
only 1 mm
in size (e.g., a length of the die) or less. The LED die are packaged
separately, which
makes them easier to handle in manufacturing and increases the available area
for
dissipating heat (e.g., 3mm x 3mm is a common package for example). In COB
and/or
CSP technology, an array of LED dies is attached directly to a high-resolution
PCB which
can dramatically increase the power density. LED arrays with power densities
of 80 watts
per square inch and higher are produced today with these CSP and COB
technologies with
higher power densities constantly being developed. LEDs may typically require
being
maintained at a junction temperature of less than 125 degrees Celsius or they
will be
damaged. Due to the heat restrictions, the packing density of LEDs in system
designs is
effectively limited by heat. Traditional air cooling techniques, such as via
heat sinks, may
not sufficiently cool the LED lighting instruments. Even adding fans to
increase airflow
over metal heat sinks provides limited heat dissipation. Although the
following description
describes cooling systems used in LED lighting systems, the cooling systems
may be
deployed in other lighting systems.
BRIEF DESCRIPTION
[0006] The light cooling systems and methods disclosed herein provide cooling
for an LED
assembly. The light cooling systems include a fluid configured to flow over
the LED
assembly to cool LEDs emitting light and to remove heat produced by the LEDs.
A pump
of the cooling system may circulate the fluid from the LED assembly to a heat
exchanger,
configured to remove the heat from the fluid, and back to the LED assembly to
continue
cooling and removing heat from the LED assembly. Additionally, light cooling
methods
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include controlling the pump to control the flowrate of the fluid through the
heat exchanger
and over/through the LED assembly.
DRAWINGS
[0007] These and other features, aspects, and advantages of the present
disclosure will
become better understood when the following detailed description is read with
reference to
the accompanying drawings in which like characters represent like parts
throughout the
drawings. The patent or application file contains at least one drawing
executed in color.
Copies of this patent or patent application publication with color drawing(s)
will be
provided by the Office upon request and payment of the necessary fee.
[0008] FIG. 1 is a schematic diagram of an embodiment of a cooling system
configured to
immersively and actively cool a light emitting diode (LED) assembly, in
accordance with
one or more current embodiments;
[0009] FIG. 2 is a perspective view of an embodiment of a lighting assembly
having the
LED assembly and the cooling system of FIG. 1, in accordance with one or more
current
embodiments;
[0010] FIG. 3 is a cross-sectional view of the lighting assembly of FIG. 2
having the
cooling system and the LED assembly, in accordance with one or more current
embodiments;
[0011] FIG. 4 is a perspective cross-sectional view of the lighting assembly
of FIG. 2
having the cooling system and the LED assembly, in accordance with one or more
current
embodiments;
[0012] FIG. 5 is a perspective view of the LED assembly of FIG. 2, in
accordance with
one or more current embodiments;
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[0013] FIG. 6A is a rear perspective view of the lighting assembly of FIG. 2
having the
cooling system and the LED assembly, in accordance with one or more current
embodiments;
[0014] FIG. 6B is a rear perspective view of another embodiment of a lighting
assembly
having the cooling system of FIG. 1, in accordance with one or more current
embodiments;
[0015] FIG. 7 is a perspective view of another embodiment of the cooling
system and the
LED assembly of FIG. 1 including a transparent enclosure, in accordance with
one or more
current embodiments;
[0016] FIG. 8 is a perspective cross-sectional view of the LED assembly and
the
transparent enclosure of FIG. 7, in accordance with one or more current
embodiments;
[0017] FIG. 9 is a bottom perspective view of the LED assembly and the
transparent
enclosure of FIG. 7, in accordance with one or more current embodiments;
[0018] FIG. 10 is a partially exploded view of the LED assembly and the
transparent
enclosure of FIG. 7, in accordance with one or more current embodiments;
[0019] FIG. 11 is a side view of the cooling system of FIG. 7 and a side view
of an
embodiment of a lighting assembly, in accordance with one or more current
embodiments;
[0020] FIG. 12 includes side views of the cooling system of FIG. 7, in
accordance with
one or more current embodiments;
[0021] FIG. 13 includes perspective views of the cooling system of FIG. 7
coupled to light
directing assemblies, in accordance with one or more current embodiments;
[0022] FIG. 14 is a perspective cross-sectional view of another embodiment of
a lighting
assembly having the LED assembly and the cooling system of FIG. 1, in
accordance with
one or more current embodiments;
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[0023] FIG. 15 is a perspective view of the lighting assembly of FIG. 14, in
accordance
with one or more current embodiments; and
[0024] FIG. 16 is a flow diagram of an embodiment of a method for controlling
the cooling
system of FIGS. 1-15, in accordance with one or more current embodiments.
DETAILED DESCRIPTION
[0025] One or more specific embodiments of the present disclosure will be
described
below. These described embodiments are only examples of the presently
disclosed
techniques. Additionally, in an effort to provide a concise description of
these
embodiments, all features of an actual implementation may not be described in
the
specification. It should be appreciated that in the development of any such
actual
implementation, as in any engineering or design project, numerous
implementation-
specific decisions must be made to achieve the developers' specific goals,
such as
compliance with system-related and business-related constraints, which may
vary from one
implementation to another. Moreover, it should be appreciated that such a
development
effort might be complex and time consuming, but may nevertheless be a routine
undertaking of design, fabrication, and manufacture for those of ordinary
skill having the
benefit of this disclosure.
[0026] When introducing elements of various embodiments of the present
disclosure, the
articles "a," "an," and "the" are intended to mean that there are one or more
of the elements.
The terms "comprising," "including," and "having" are intended to be inclusive
and mean
that there may be additional elements other than the listed elements.
Additionally, it should
be understood that references to "one embodiment" or "an embodiment" of the
present
disclosure are not intended to be interpreted as excluding the existence of
additional
embodiments that also incorporate the recited features.
[0027] Turning now to the drawings, FIG. I is a schematic diagram of a cooling
system
100 configured to actively cool an LED assembly 102. The cooling system 100
includes
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an enclosure 104 configured to at least partially enclose and/or house the LED
assembly
102 and a heat exchanger 106 fluidly coupled to the enclosure 104. The cooling
system
100 also includes a pump 108 configured to circulate fluid (e.g., coolant,
mineral oil, water,
a hydrocarbon fluid, a silicon fluid, or a combination thereof) along a
cooling circuit 110
through the heat exchanger 106, through the enclosure 104, through and/or over
the LED
assembly 102, and back to the pump 108. In certain embodiments, the cooling
system 100
may include the LED assembly 102 or a portion thereof.
100281 The LED assembly 102 may be any assembly including one or more LEDs.
For
example, to provide lighting for applications such as television and theater
sets, film sets,
tradeshows, and any one of the range of permanent, semi-permanent, and
temporary
settings, the LED assembly 102 may include multiple LEDs configured to emit
light.
While emitting light, the LEDs may produce heat and a temperature of a
surrounding area
(e.g., an area adjacent to the LED assembly 102 and/or within/adjacent to the
enclosure
104) may generally increase.
100291 During operation, the cooling system 100 is configured to absorb the
heat generated
by the LED assembly 102 and to transfer the heat to ambient air. For example,
as the pump
108 circulates the fluid through the enclosure 104 and/or through the LED
assembly 102,
the fluid may absorb the heat generated by the LED assembly 102. The heat
exchanger
106 may include a radiator and/or fan(s) configured to actively draw ambient
air
toward/across the heat exchanger 106 to cool the fluid traveling through the
heat exchanger
106 and along the cooling circuit 110. In certain embodiments, the heat
exchanger 106
may include a second fluid (e.g., in addition to or in place of the ambient
air) configured to
exchange heat with the fluid flowing along the cooling circuit 110.
100301 The pump 108 may be a variable speed pump configured to circulate the
fluid
through the cooling circuit 110. In certain embodiments, a housing of the pump
108 may
include a flexible diaphragm configured to expand and/or retract based on a
volume of the
fluid flowing along the cooling circuit 110. For example, as the fluid absorbs
heat at and
from the LED assembly 102, the fluid may expand (e.g., thermal expansion). As
the fluid
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flows from the LED assembly 102 and the enclosure 104, the flexible diaphragm
of the
pump 108 may expand to allow of the increased volume of fluid to pass through
the pump
without affecting the flowrate of the fluid through the pump 108 and along the
cooling
circuit 110. In some embodiments, the flexible diaphragm of the pump 108 may
be a
service panel configured to allow access to internal portions of the pump 108.
As described
in greater detail below, in certain embodiments, the flexible diaphragm may be
located
elsewhere along the cooling circuit 110 (e.g., in addition to or in place of
be located at the
pump 108) to facilitate thermal expansion of the fluid in the cooling circuit
110.
100311 The LED assembly 102 is configured to emit light, which may pass
through the
fluid circulating between the LED assembly 102 and the enclosure 104 and
through the
enclosure 104. As such, the LED assembly 102 is configured to provide lighting
for the
various applications described herein (e.g., motion picture and television
lighting and other
applications that may benefit from high intensity lighting) while being cooled
by the
cooling system 100. The LEDs of the LED assembly 102 may include
varied/multiple
configurations. For example, the LED assembly 102 may include chip scale
packaging
(CSP) arrays (e.g., bi-color CSP arrays). CSP technology may benefit from very
high
density of LED chips in a specified area (e.g., per square inch/centimeter),
and CSP
technology may utilize different colors of individual LEDs. For example, CSP
technology
may include a five color configuration (e.g., warm white, cool white, red,
green, and blue),
a four color configuration (e.g., white, red, green, and blue), a three color
configuration
(e.g., red, green, and blue), a bi-color white configuration (e.g., warm white
and cool
white), a single white configuration, and/or a single color configuration.
[0032] In some embodiments, the LED assembly 102 may include single color chip
on
board ("COB") arrays. The COB arrays may include a relatively large number of
LEDs
bonded to a single substrate and a layer of phosphor placed over the entire
array. An
advantage of COB technology is very high LED density per specified area (e.g.,
per square
inch/centimeter). Additionally or alternatively, the LED assembly 102 may
include
discrete LEDs.
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[0033] The cooling system 100 includes a controller 120 configured to control
the LED
assembly 102, the heat exchanger 106, the pump 108, or a combination thereof.
For
example, the controller 120 may control some or all LEDs of the LED assembly
102 to
cause the LEDs to emit light. Additionally or alternatively, the controller
120 may control
operation of the heat exchanger 106 to cause the heat exchanger 106 to
exchange more or
less heat between the fluid and the ambient air. For example, the controller
120 may control
fans of the heat exchanger 106 to control an air flow rate through/over the
heat exchanger
106. In certain embodiments, the fans of the heat exchanger 106 may be
controlled via
pulse width modulated (PWM) power. The fans may be controlled based on the
temperature at the LED assembly 102. In some embodiments, to reduce a noise
output of
the fans of the heat exchanger 106, the controller 120 may operate the fans
only when
cooling of the fluid by other means (e.g., via the radiator without active
airflow) is
insufficient.
[0034] As illustrated, the cooling system 100 may include a sensor 121
disposed at the
LED assembly 102 and configured to output a signal (e.g., an input signal)
indicative of
the temperature at the LED assembly 102 and/or a temperature of the fluid
adjacent to the
LED assembly 102. The sensor 121 may be any suitable temperature/thermal
sensor, such
as a thermocouple. In certain embodiments, the cooling system 100 may include
other
thermal sensor(s) disposed within the fluid and configured to output a signal
indicative of
a temperature of the fluid (e.g., within the enclosure 104) and/or disposed at
the enclosure
104 and configured to output a signal indicative of a temperature at the
enclosure 104.
[0035] Further, the controller 120 may control operation of the pump 108 to
cause the
pump 108 to circulate the fluid along the cooling circuit 110 at particular
flowrates. For
example, based on the temperature at the LED assembly 102 and/or at the
enclosure 104
(e.g., based on the signal indicative of the temperature at the LED assembly
102 received
from the sensor 121), the controller 120 may be configured to output a signal
(e.g., an
output signal) to the pump 108 indicative of instructions to adjust the
flowrate of the fluid
flowing through the cooling circuit 110.
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[0036] As illustrated, the controller 120 includes a processor 122 and a
memory 124. The
processor 122 (e.g., a microprocessor) may be used to execute software, such
as software
stored in the memory 124 for controlling the cooling system 100 (e.g., for
controller
operation of the pump 108 to control the flowrate of fluid through the cooling
circuit 110).
Moreover, the processor 122 may include multiple microprocessors, one or more
"general-
purpose" microprocessors, one or more special-purpose microprocessors, and/or
one or
more application specific integrated circuits (ASICS), or some combination
thereof. For
example, the processor 122 may include one or more reduced instruction set
(RISC) or
complex instruction set (C1SC) processors.
[0037] The memory device 124 may include a volatile memory, such as random-
access
memory (RAM), and/or a nonvolatile memory, such as read-only memory (ROM). The
memory device 124 may store a variety of information and may be used for
various
purposes. For example, the memory device 124 may store processor-executable
instructions (e.g., firmware or software) for the processor 122 to execute,
such as
instructions for controlling the cooling system 100. In certain embodiments,
the controller
120 may also include one or more storage devices and/or other suitable
components. The
storage device(s) (e.g., nonvolatile storage) may include ROM, flash memory, a
hard drive,
or any other suitable optical, magnetic, or solid-state storage medium, or a
combination
thereof. The storage device(s) may store data (e.g., measured temperatures at
the LED
assembly 102), instructions (e.g., software or firmware for controlling the
cooling system
100), and any other suitable data. The processor 122 and/or the memory device
124, and/or
an additional processor and/or memory device, may be located in any suitable
portion of
the system. For example, a memory device for storing instructions (e.g.,
software or
firmware for controlling portions of the cooling system 100) may be located in
or
associated with the cooling system 100.
[0038] Additionally, the controller 120 includes a user interface 126
configured to inform
an operator of the temperature at the LED assembly 102 and/or of the flowrate
of the fluid
through the cooling circuit 110. For example, the user interface 126 may
include a display
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and/or other user interaction devices (e.g., buttons) configured to enable
operator
interactions.
[0039] FIG. 2 is a perspective view of an embodiment of a lighting assembly
130 having
the cooling system 100 and the LED assembly 102 of FIG. 1. The lighting
assembly 130
includes a reflector 132 (e.g., a parabolic reflector) configured to reflect
light emitted by
the LED assembly 102. For example, the light emitted by the LED assembly 102
may pass
through the fluid disposed between the LED assembly 102 and the enclosure 104,
through
the enclosure 104, and may be reflected by the reflector 132 outwardly. The
reflector 132
is coupled to a chassis 134 (e.g., a housing) of the lighting assembly 130. In
certain
embodiments, the LED assembly 102, the enclosure 104, and/or other portions of
the
cooling system 100 may be coupled to the chassis 134. For example, as
described in greater
detail below, the heat exchanger 106 and/or the pump 108 of the cooling system
100 may
be coupled to the chassis 134.
[0040] FIG. 3 is a cross-sectional view of the lighting assembly 130 of FIG. 2
having the
cooling system 100. As illustrated, the cooling system 100 includes the
enclosure 104, the
LED assembly 102 disposed in the enclosure 104, the heat exchanger 106
configured to
exchange heat with the fluid, and the pump 108 configured to drive circulation
of the fluid.
Additionally, the cooling system 100 includes an inlet pipe 140 coupled to the
pump 108
and to a fluid inlet 142 of the enclosure 104. Further, the cooling system 100
includes an
outlet pipe 144 coupled to a fluid outlet 146 of the enclosure 104 and to the
heat exchanger
106. In certain embodiments, the inlet pipe 140 and/or the outlet pipe 144 may
extend into
the LED assembly 102 and/or into the enclosure 104.
[0041] As illustrated, the fluid inlet 142 is disposed generally along a
centerline of the
enclosure 104 and the LED assembly 102. The pump 108 is configured to drive
the fluid
from the inlet pipe 140, into the fluid inlet 142, generally along the
centerline of the LED
assembly 102 and the enclosure 104, into and along a gap between the LED
assembly 102
and the enclosure (e.g., a gap where the fluid absorbs heat generated by the
LED assembly
102), out of the fluid outlet 146, and into the outlet pipe 144 (e.g., along
the cooling circuit
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110). After absorbing heat at the LED assembly 102, the fluid circulates
through the heat
exchanger 106 and returns to the pump 108. At the heat exchanger 106, the
fluid rejects
the heat absorbed at the LED assembly 102. For example, the heat exchanger 106
includes
a radiator 150 and fans 152 configured to draw air (e.g., ambient air) across
the radiator
150. The air drawn across the radiator 150 may absorb heat from the fluid
flowing through
the radiator 150 (e.g., heat transferred from the fluid to the radiator 150),
thereby cooling
the fluid for subsequent circulation along the cooling circuit 110 and back
through the LED
assembly 102 and the enclosure 104.
[0042] Additionally, in certain embodiments, the heat exchanger 106 may not
reject all the
heat absorbed by the fluid at the LED assembly 102, such that the fluid
retains at least some
of the heat absorbed at the LED assembly 102. As such, a temperature of the
fluid along
the cooling circuit 110 (e.g., an average temperature) may increase, thereby
increasing a
volume of the fluid. The cooling system 100 includes a flexible membrane 154
at the pump
108 configured to expand due to heating of the fluid and to retract due to
cooling of the
fluid (e.g., to accommodate volumetric changes of the fluid along the cooling
circuit 110).
In certain embodiments, the flexible membrane 154 may be included elsewhere
within the
cooling system 100.
[0043] The cooling system 100 includes a valve 156 fluidly coupled to the
cooling circuit
110. The valve 156 may be configured to bleed air and/or fluid from the
cooling circuit
110, such as when fluid is added to the cooling circuit 110 (e.g., the valve
156 may be a
bleed valve). Additionally or alternatively, fluid may be added to the cooling
circuit 110
via the valve 156 (e.g., the valve 156 may be a fill valve). In certain
embodiments, the
cooling system 100 may include multiple valves 156 with a first valve 156
being a bleed
valve and a second valve 156 being a fill valve.
[0044] As described above, the controller 120 may be configured to control the
LED
assembly 102, the heat exchanger 106, the pump 108, or a combination thereof.
For
example, the controller 120 may control some or all LEDs of the LED assembly
102 to
cause the LEDs to emit light. Additionally, the controller 120 may control a
rotation rate
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of the fans 152 and/or a flow rate of the fluid along the cooling circuit 110.
For example,
based on feedback received from the sensor 121 at the LED assembly 102 (e.g.,
the
temperature at the LED assembly 102, the controller 120 may control the
rotation rate of
the fans 152 and/or the flow rate of the fluid. More specifically, in response
the temperature
at the LED assembly 102 being greater than a target temperature and a
difference between
the temperature at the LED assembly 102 and the target temperature exceeding a
threshold
value, the controller may increase the rotation rate of the fans 152 and/or
may increase the
flow rate of the fluid. In response the temperature at the LED assembly 102
being less than
the target temperature and the difference between the temperature at the LED
assembly
102 and the target temperature exceeding a threshold value, the controller may
decrease
the rotation rate of the fans 152 and/or may decrease the flow rate of the
fluid.
100451 FIG. 4 is a perspective cross-sectional view of the lighting assembly
130 of FIG. 2
having the cooling system 100. As illustrated, the fluid of the cooling system
100 is
configured to flow from the inlet pipe 140, through the fluid inlet 142, and
through an inner
annular passage 160 formed within the LED assembly 102 (e.g., in a direction
162). As
such, the fluid enters the LED assembly 102 as a chilled fluid. The inner
annular passage
160 is coupled to the fluid inlet 142 and to an end 164 of the LED assembly
102. From the
inner annular passage 160, the fluid circulates through an end passage 166
formed between
the end 164 of the LED assembly 102 and an end 168 of the enclosure 104, as
indicated by
arrows 170. From the end passage 166, the fluid circulates into an outer
annular passage
172 formed between the LED assembly 102 and the enclosure 104, as indicated by
arrow
174. As the fluid flows through the outer annular passage 172, the fluid
absorbs heat
generated by the LED assembly 102. From the outer annular passage 172, the
fluid exits
the enclosure 104 through the fluid outlet 146 and flows into the outlet pipe
144. As such,
the fluid exits the enclosure 104 as a heated fluid. After passing through the
heat exchanger
106 and the pump 108 of the cooling system 100, the fluid circulates back to
through the
LED assembly 102 and the enclosure 104 to continue cooling the LED assembly
102.
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[0046] The lighting assembly 130 is a side emission configuration of the
lighting assembly,
such that the lighting assembly 130 is configured to emit light radially
outwardly (e.g.,
from sides of the lighting assembly 130) and through the fluid and the
enclosure 104. As
described in greater detail below in reference to FIGS. 14 and 15, the cooling
system 100
may include a front emission configuration of the lighting assembly, such as
in place of or
in addition to the side emission configuration of FIGS. 2-5.
[0047] FIG. 5 is a perspective view of the LED assembly 102 of FIG. 2. As
illustrated, the
LED assembly 102 includes a tower 180 and LED arrays 182 mounted to the tower
180.
As illustrated, the tower 180 is a hexagonal structure formed by panels 184
(e.g., six panels
184) with nine LED arrays 182 mounted on each panel 184. In certain
embodiments, the
tower may include more or fewer panels 184 (e.g., three panels 184, four
panels 184, eight
panels 184, etc.) and/or each panel 184 may include more or fewer LED arrays
182 (e.g.,
one LED array 182, two LED arrays 182, five LED arrays 182, twenty LED arrays
182,
etc.). In some embodiments, the tower 180 may be shaped differently in other
embodiments and/or may be omitted. For example, the LED arrays 182 may be
mounted
directly to the enclosure 104 in some embodiments. In certain embodiments, the
LED
assembly 102 may include other LED configurations in addition to or in place
of the LED
arrays 182.
[0048] The LED arrays 182 of the LED assembly 102 are configured to emit light
outwardly through the fluid flowing between the LED assembly 102 and the
enclosure 104
(e.g., through the outer annular passage 172 formed between the LED assembly
102 and
the enclosure 104) and through the enclosure 104. The fluid may be transparent
or semi-
transparent such that the fluid is configured to allow the light to pass
through the fluid
toward the enclosure 104. For example, the fluid may be a dielectric and/or
electrically
insulating fluid having a refractive index of between 1.4 and 1.6. In some
embodiments,
the enclosure 104 enclosing the fluid may be acrylic, polycarbonate, glass
(e.g., borosilicate
glass), or another material having a refractive index between about 1.44 ¨
1.5. In certain
embodiments, the LEDs of the LED arrays 182 may include silicone (e.g., a
silicone layer)
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through which light emitted by the LEDs passes. The silicone may have a
refractive index
of about 1.38-1.6. As such, a type of fluid (e.g., the fluids having the
refractive indices
recited above) may facilitate light passage from the LEDs, through the fluid,
and toward
the enclosure 104. Additionally, the refractive index of the layer of the LED
(e.g., the
silicone), the fluid, and/or the enclosure 104 may generally be matched (e.g.,
within a
difference threshold). In some embodiments, the fluid and/or the enclosure 104
may
behave as lens configured to optically shape light provided by the LED
assembly 102. For
example, the fluid and/or the enclosure 104 having the specific refractive
indices described
above may allow the fluid and/or the enclosure to shape the light in a
desirable manner.
[0049] Additionally or alternatively, the fluid may include a mineral oil
having a relatively
long shelf life (e.g., about twenty-five years) or a fluid having properties
similar to mineral
oil. The fluids may be non-corrosive such that the fluids facilitate pumping
along the
cooling circuit 110 by the pump 108 and compatible with plastics and other
system
materials. Further, such fluids may generally have a relatively low viscosity,
which may
allow directly cooling the electronics of the LED assembly 102 (e.g., the LED
arrays 182,
wiring coupled to the LED arrays 182 and to printed circuit boards ("PCB's"),
and other
electronic components of the LED assembly 102) without affecting the
performance/functionality of the electronics. In certain embodiments, the type
of the fluid
included in the cooling circuit 110 may depend on an amount of LED arrays 182
and/or an
amount of LEDs generally included in the LED assembly 102, a
structure/geometry of the
LED assembly 102, a density of LEDs of the LED assembly 102, an amount of heat
generated by the LED assembly 102, or a combination thereof. During operation,
the LED
arrays 182 of the LED assembly 102 may have a power density of between 20W ¨
300W
per square inch, between 50W ¨ 250W per square inch, and other suitable power
densities.
In an aspect, each LED array 182 may have a surface area of 4 square inches or
less. Due
to the cooling systems mentioned herein, the LED arrays 182 may be operated at
the
aforementioned power densities for longer than 30 seconds, 1 minute, 1 hour,
and 100
hours. In some embodiments, the LED assembly 102 may have a total power of
400W ¨
5000W.
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[0050] In some embodiments, the refractive index of the fluid disposed between
the LED
arrays 182 and the enclosure 104 may cause light to more easily leave the LED
arrays 182
compared to an embodiment in which the LED arrays 182 are exposed to air. This
may
result in a color shift of the light emitted from the LED arrays 182. The
controller 120 may
control the LED arrays 182 (e.g., the colors and/or color temperatures of the
LED arrays
182) based on the potential color shift of the emitted light.
[0051] The enclosure 104 may include clear, transparent, and/or semi-
transparent materials
such that the light emitted by the LED assembly 102 may pass through the
enclosure 104
(e.g., after passing through the fluid disposed within and/or flowing through
the outer
annular passage 172) and outwardly from the enclosure 104. For example, the
enclosure
104 may be formed of a clear plastic and/or glass (e.g., borosilicate glass).
In certain
embodiments, the enclosure 104 may include poly(methyl methacrylate) ("PMMA")
and/or other acrylics.
[0052] As illustrated, the LED assembly 102 includes printed circuit boards
("PCBs") 190
coupled to a base PCB 192, the LED arrays 182, and the end 164 (e.g., end
plate) of the
LED assembly 102. For example, each PCB 190 extends generally along a
respective panel
184 and is coupled (e.g., physically and electrically coupled via connectors
193) to the
LED arrays 182 coupled to the respective panel 184. Each connector 193 is
coupled to a
respective LED array 182 at connections 194. In certain embodiments, each LED
array
182 may be configured to snap/click into place on the panel 184. For example,
each panel
184 may include features configured to receive the LED arrays 182 via a snap
or click
mechanism to facilitate assembly of the LED assembly 102.
[0053] FIG. 6A is a rear perspective view of the lighting assembly 130 of FIG.
2 having
the cooling system 100. As generally described above, the cooling system 100
includes
the inlet pipe 140 configured to flow fluid (e.g., chilled fluid) into the LED
assembly 102
and the enclosure 104 and the outlet pipe 144 configured to receive fluid
(e.g., heated fluid)
from the LED assembly 102 and the enclosure 104. The fluid circulates from the
outlet
pipe 144, through the radiator 150 of the heat exchanger 106, through the pump
108, and
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back to the inlet pipe 140. As illustrated, the cooling system includes four
fans 152
configured to draw air across the radiator 150 to cool the fluid passing
through the radiator
150. In certain embodiments, the cooling system may include more or fewer fans
152 (e.g.,
one fan 152, two fans 152, three fans 152, five fans 152, ten fans 152, etc.).
The fans 152
are positioned above the radiator 150, such that the heat transferred from the
fluid passing
through the radiator 150 moves generally upwardly toward/through the fans 152.
Additionally, the heat exchanger 106 and the pump 108 are mounted to the
chassis 134 of
the lighting assembly 130.
[0054] FIG. 6B is a rear perspective view of an embodiment of a lighting
assembly 187
having the cooling system 100 of FIG. 1. The lighting assembly 187 includes
the inlet pipe
140 configured to flow fluid (e.g., chilled fluid) into the LED assembly 102
and the
enclosure 104 and the outlet pipe 144 configured to receive fluid (e.g.,
heated fluid) from
the LED assembly 102 and the enclosure 104. The fluid circulates from the
outlet pipe 144
to the radiator 150, through the radiator 150, to an intermediate pipe 189,
through an
expansion chamber 188 coupled to the intermediate pipe 189, and back to the
inlet pipe
140 via the pump 108. The expansion chamber 188 is configured to expand due to
heating
of the fluid and to retract due to cooling of the fluid (e.g., to accommodate
volumetric
changes of the fluid along the cooling circuit 110). In certain embodiments,
the expansion
chamber 188 may be included elsewhere along the cooling circuit 110, such as
along the
inlet pipe 140 and/or along the outlet pipe 144.
[0055] As illustrated, the lighting assembly 187 includes a first bracket 191
coupled to the
radiator 150 and the expansion chamber 188 and a second bracket 195 coupled to
the
radiator 150 and the pump 108. The radiator 150 and the expansion chamber 188
are
mounted to the first bracket 191, and the first bracket 191 is mounted to the
chassis 134,
such that the first bracket 191 is configured to support a weight of the
expansion chamber
188 and/or at least a portion of a weight of the radiator 150 (e.g., to
transfer forces
associated with the weight(s) to the chassis 134). Additionally, the radiator
150 and the
pump 108 are mounted to the second bracket 195, and the second bracket 195 is
mounted
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to the chassis 134, such that the second bracket 195 is configured to support
a weight of
the pump 108 and/or at least a portion of the weight of the radiator 150
(e.g., to transfer
forces associated with the weight(s) to the chassis 134).
[0056] FIG. 7 is a perspective view of an LED assembly 196 and an enclosure
198 that
may be included the cooling system 100 of FIG. 1. As illustrated, the LED
assembly 196
is disposed within the enclosure 198. The LED assembly 196 includes a fluid
inlet 200
configured to receive the fluid flowing along the cooling circuit 110 (e.g.,
as indicated by
arrow 202) and a fluid outlet 204 configured to flow the fluid from the
enclosure and the
LED assembly 196 to the cooling circuit 110 (e.g., as indicated by arrow 206)
(although
the fluid direction may be reversed such that the fluid enters through the
fluid outlet 204,
for example, and exits through the fluid inlet 200). Additionally, the
enclosure 198
includes a base 208 and a cylinder 210 extending from the base 208. In certain
embodiments, the LED assembly 196 and/or the enclosure 198 of the cooling
system 100
may be included in the lighting assembly of FIGS. 2-6.
[0057] The LED assembly 196 includes a tower 220 and the LED arrays 182
mounted to
the tower 220. As illustrated, the tower 220 is a hexagonal structure with
nine LED arrays
182 mounted on each of the six sides of the hexagonal structure. In certain
embodiments,
the tower 220 may include more or fewer sides (e.g., three sides, four sides,
eight sides,
etc.) and/or each side may include more or fewer LED arrays 182 (e.g., one LED
array 182,
two LED arrays 182, five LED arrays 182, twenty LED arrays 182, etc.). In some
embodiments, the tower 220 may be shaped differently in other embodiments
and/or may
be omitted. For example, the LED arrays 182 may be mounted directly to the
enclosure
198 in some embodiments. In certain embodiments, the LED assembly 196 may
include
other LED configurations in addition to or in place of the LED arrays 182.
[0058] The LED arrays 182 of the LED assembly 196 are configured to emit light
outwardly through the fluid flowing between the LED assembly 196 and the
enclosure 198
(e.g., through an outer annular passage 224 of the cooling system 100) and
through the
enclosure 198. In some embodiments, the enclosure 198 enclosing the fluid may
be acrylic,
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polycarbonate, glass (e.g., borosilicate glass), or another material having a
refractive index
between about 1.44 ¨ 1.5. Additionally, the refractive index of the layer of
the LED (e.g.,
the silicone), the fluid, and/or the enclosure 198 may generally be matched
(e.g., within a
difference threshold).
[0059] The enclosure 198 may include clear, transparent, and/or semi-
transparent materials
such that the light emitted by the LED assembly 196 may pass through the
enclosure 198
(e.g., after passing through the fluid disposed within and/or flowing through
the outer
annular passage 224) and outwardly from the enclosure 198. For example, the
enclosure
198 may be formed of a clear plastic and/or glass (e.g., borosilicate glass).
In certain
embodiments, the enclosure 198 may include poly(methyl methacrylate) ("PMMA")
and/or other acrylics.
[0060] The cooling system 100 is configured to flow the fluid into the fluid
inlet 200,
through the outer annular passage 224 between the LED assembly 196 and the
enclosure
198, and toward an end 230 of the tower 220. The end 230 is disposed generally
opposite
of the base 208. The tower 220 includes an inner annular passage 232 extending
from the
end 230 to the base 208. As illustrated, the inner annular passage 232 is
fluidly coupled to
the outer annular passage 224 at the end 230 of the tower 220. The cooling
system 100 is
configured to flow the fluid from the outer annular passage 224 and into the
inner annular
passage 232 via the end 230. The inner annular passage 232 is fluidly coupled
to the fluid
outlet 204 such that the fluid may pass through the tower 220, via the inner
annular passage
232, and out of the tower 220 and the enclosure 198 at the fluid outlet 204.
[0061] As the fluid passes over and through the LED assembly 196 (e.g., over
the LED
arrays 182 and through the tower 220), the fluid is configured to absorb heat
generated by
operation of the LED arrays 182. For example, because the fluid is configured
to absorb
heat generated by the LED arrays 182 while flowing through both the outer
annular passage
224 and the inner annular passage 232, the cooling system 100 is configured to
significantly
increase an amount of heat that may be absorbed compared to embodiments of
cooling
systems that extract heat only from an interior or exterior of a light source.
Additionally,
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because the fluid is generally transparent and/or semi-transparent (e.g., the
fluid has a
refractive index generally between 1.4-1.5), the fluid may have minimal/no
effects on the
light emitted from the LED assembly 196 and through the fluid. As such, the
fluid may
actively cool the LED assembly 196 during operation of the LED assembly 196
with little
to no effect on a quality of light emitted from the LED assembly 196.
[0062] The LED assembly 196 is a side emission configuration of a lighting
assembly,
such that the LED assembly 196 is configured to emit light radially outwardly
(e.g., from
sides of the LED assembly 196) and through the fluid and the enclosure 198. As
described
in greater detail below in reference to FIGS. 14 and 15, the cooling system
100 may also
include a front emission configuration of the lighting assembly, such as in
place of or in
addition to the side emission configuration of FIGS. 7-10.
[0063] FIG. 8 is a perspective cross-sectional view of the LED assembly 196
and the
enclosure 198 of FIG. 7. As described above, the enclosure 198 is configured
to receive
the fluid from the pump 108 through the fluid inlet 200. The fluid is then
configured to
contact the tower 220 and a base 300 of the LED assembly 196 coupled to the
tower 220.
The tower 220 and the base 300 are configured to direct the fluid upwardly
along the outer
annular passage 224. The fluid is then configured to flow through the end 230
and into the
inner annular passage 232. As illustrated, the inner annular passage 232 is
formed between
and by the tower 220 and PCBs 302 of the LED assembly 196. The fluid is
configured to
flow downwardly within the inner annular passage 232 toward a base PCB 304
electrically
coupled to the PCBs 302. After passing over the PCBs 302 and/or the base PCB
304, the
fluid is configured to exit the tower 220 and the enclosure 198 at the fluid
outlet 204. As
mentioned with respect to FIG. 7, the fluid direction may be reversed such
that the fluid
may be configured to flow in through the fluid outlet 204, up through the
inner annular
passage 232, through the end 230, and down the outer annular passage 224, and
out the
fluid inlet 200.
[0064] The PCBs 302 may be electrically coupled to the LED arrays 182 such
that the
PCBs 302 may provide power and/or communication with the LED arrays 182. For
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example, the LED assembly 196 may include wiring extending outwardly between
the
PCBs 302 and the LED arrays 182. As such, the fluid may flow over the PCBs 302
and
the wiring extending between the PCBs 302 and the LED arrays 182 to cool and
absorb
heat from the tower 220 (e.g., heat generated by the LED arrays 182 that is
transferred
to/absorbed by the tower 220), from the PCBs 302, and/or from the wiring.
Additionally,
the fluid may flow over the base PCB 304 and may absorb heat from the base PCB
304.
For example, the base PCB 304 includes a wet side 306 configured to contact
the fluid and
a dry side generally opposite the wet side 306 that is configured to remain
dry (e.g., to not
contact the fluid). As generally described above, the fluid may be dielectric
and/or
electrically insulating such that the fluid may have minimal/no electrical
effects on the LED
arrays 182, the PCBs 302, the base PCB 304, and the wiring of the LED assembly
196.
[0065] FIG. 9 is a bottom perspective view of the LED assembly 196 and the
enclosure
198 of FIG. 7. As illustrated, the base PCB 304 includes a dry side 400
configured to
remain generally dry (e.g., to not contact the fluid during operation of the
cooling system
100). The LED assembly 196 includes a gasket 402 configured to form a seal
between the
enclosure 198 and the LED assembly 196 (e.g., between the base 208 of the
enclosure 198
and the base PCB 304 of the LED assembly 196). As such, the LED assembly 196
may be
remain dry at the dry side 400 of the base PCB 304, and the cooling system 100
may be
configured to flow the fluid through the enclosure 198 and the tower 220
without leaking
fluid.
[0066] FIG. 10 is a partially exploded view of the LED assembly 196 and the
enclosure
198 of FIG. 7. The LED assembly 196 is configured to insert into and to be
removed from
the enclosure 198 as generally indicated by arrow 500. For example, to replace
portions
of the LED assembly 196 (e.g., the LED arrays 182, the PCBs 302, the base PCB
304,
wiring, etc.), the LED assembly 196 and the enclosure 198 may be disassembled
by
removing the LED assembly 196 from the enclosure 198 along an axis generally
parallel
to arrow 500. Additionally, while the LED assembly 196 and the enclosure 198
are
disposed in the illustrated positions (e.g., with the LED assembly 196 and the
enclosure
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198 extending downwardly), the LED assembly 196 may be removed from the
enclosure
198 with a minimal loss and/or splashing of the fluid using threaded
enclosures, a gasket,
a latch, and/or other securing mechanisms. To assemble/reassemble the LED
assembly
196 into the enclosure 198, the LED assembly 196 may be inserted into the
enclosure 198
along the axis generally parallel to the arrow 500. Thus, the configuration
and coupling of
the LED assembly 196 and the enclosure 198 described herein may facilitate
quick and
easy maintenance of the LED assembly 196.
[0067] FIG. 11 is a side view of the cooling system 100 of FIG. 7 and a side
view of a
lighting assembly 600. As illustrated, the base 208 of the enclosure 198 is
coupled to a
heat exchanger 601. After absorbing heat from and at the LED assembly 196, the
fluid is
configured to flow into and through the heat exchanger 601. The heat exchanger
601
includes a radiator 602 configured to exchange heat from the fluid to ambient
air adjacent
to the heat exchanger 601. The heat exchanger 601 may include the radiator 602
on each
of four sides of the heat exchanger 601 (e.g., four radiators 602). In certain
embodiments,
the heat exchanger 601 may include more of fewer sides with each side having
the radiator
602. The radiator 602 includes fins 604 configured to transfer heat from the
fluid (e.g., to
absorb heat from the fluid) to the ambient air. In some embodiments, the heat
exchanger
601 may include other shapes configured to cool the fluid (e.g., a sphere, a
cylinder, etc.).
[0068] The LED arrays 182 of the LED assembly 196 extend outwardly from the
base 208
of the enclosure 198 a distance 610. In certain embodiments, the distance 610
may be
between about three inches and about nine inches. In some embodiments, the
distance 610
may be about five and one-half inches. Additionally, the cooling system 100
extends a
generally vertical distance 612 and a generally horizontal distance 614. In
certain
embodiments, the generally vertical distance 612 may between about ten inches
and about
twenty inches, and/or the generally horizontal distance 614 may be between
about seven
inches and about seventeen inches. In some embodiments, the generally vertical
distance
612 may be fourteen inches, and/or the generally horizontal distance 614 may
be twelve
inches.
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[0069] The lighting assembly 600 is a prior art lighting assembly having a
lighting area
620 configured to emit light. A back portion of the lighting area 620 may be a
heat sink
configured to absorb/transfer heat from the lighting area 620. As illustrated,
the cooling
system 100 is generally smaller and more compact than the lighting area 620
and the heat
sink of the lighting assembly 600. Additionally, as generally described above,
the cooling
system 100 is configured to provide sufficient cooling for the LED assembly
196 as the
LED assembly 196 operates at 1500W. The lighting assembly 600 may be
configured to
provide cooling for lights of the lighting area 620 operating at 400W. As
such, the cooling
system 100 may be more versatile than the lighting assembly 600, and prior art
lighting
assemblies generally, by providing a more compact design configured to operate
at
significantly higher powers. In certain embodiments, the LED assembly 102
and/or the
enclosure 104 of the cooling system 100 may be coupled to the heat exchanger
601, such
that the heat exchanger 601 is configured to exchange heat with the fluid
circulating
through the LED assembly 102 and the enclosure 104.
[0070] FIG. 12 includes side views of the cooling system 100 of FIG. 7. The
cooling
system 100 includes a cover 700 configured to fit over/onto the enclosure 198.
The cover
700 includes materials configured to convert a color correlated temperature
("CCT") of
light emitted by the LED assembly 196. For example, the cover 700 may include
and/or
be formed of phosphor and may be configured to convert a cool white CCT of
about 5600K
to a warmer white CCT of about 4300K, about 3200K, and other CCT's. In certain
embodiments, the cover 700 may be injection molded plastic, silicone, coated
glass, or a
combination thereof In certain embodiments, the cover 700 may fit over/onto
the
enclosure 104, such that the cover 700 converts a CCT of light emitted by the
LED
assembly 102 through the enclosure 104.
[0071] The cover 700 is configured to slide onto and off of the enclosure 198,
as generally
noted by arrow 702. For example, the cover 700 may be easily field changeable
such that
an operator may slide the cover 700 onto and off of the enclosure 198.
Additionally, light
produced by a low cost single color version of the LED assembly 196 may easily
be
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converted to any CCT with the addition of the cover 700, which may be of
relatively low
cost. Further, the cover 700 may be significantly more power efficient
compared to
traditional embodiments, because the cover 700 is not a filter removing a
portion of light
emitted by the LED assembly 196. Instead, the cover 700 is configured to
convert light to
a desired color and CCT.
[0072] In certain embodiments, the LED assembly 196 may be configured to emit
a blue
light, cool white light (e.g., 5000K or higher), or other colors. The cover
700 may adapted
for any suitable color and/or white such that light emitted from a single-
color version of
the LED assembly 196 (e.g., a blue light LED assembly 196 or a cool white
light LED
assembly 196) may be converted into any CCT and/or any color with no change to
the LED
assembly 196 or other electronics of the cooling system 100.
[0073] As illustrated, the cover 700 is configured to contact the enclosure
198 while the
cover 700 is disposed on the enclosure 198. The contact between enclosure 198
and the
cover 700 may allow the enclosure 198 to transfer heat to the cover 700. The
fluid flowing
within the enclosure 198 may be configured to cool both enclosure 198 and the
cover 700
(e.g., the fluid may absorb heat from the enclosure 198 to facilitate cooling
of the cover
700).
[0074] FIG.
13 includes perspective views of the cooling system 100 of FIG. 7 coupled
to light directing assemblies 800, 802, and 804 configured to direct light
emitted by the
LED assembly 102 of the cooling system 100. For example, the light directing
assembly
800 is a high bay assembly configured to be disposed in building setting and
to direct light
emitted by the LED assembly 102 downwardly. The light directly assembly 802 is
a space
light directing assembly configured to be disposed in a studio to provide
environment
lighting. Additionally, the light directly assembly 804 is an umbrella
assembly configured
to be disposed in a studio and to generally focus light emitted by the LED
assembly 102.
[0075] FIG. 14 is a perspective cross-sectional view of another embodiment of
a lighting
assembly 820 having an LED assembly 822 and the cooling system 100 of FIG. 1.
The
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lighting assembly 820 is a front emission configuration of a lighting assembly
that may be
included in the cooling system 100, such that the lighting assembly 820 is
configured to
emit light outwardly through a front portion of the lighting assembly 820, as
indicated by
arrow 823, rather than through side of a lighting assembly (e.g., as in
lighting assembly
embodiments of FIGS. 2-13). Accordingly, the cooling system 100 may include a
lighting
assembly having a side emission configuration, a front emission configuration,
and/or
others.
100761 The lighting assembly 820 includes a chassis 824 configured to receive
and flow
the fluid to cool the LED assembly 822. As illustrated, the LED assembly 822
is disposed
within and mounted to the chassis 824. Additionally, the lighting assembly 820
includes a
cover 826 coupled to the chassis 824. The cover 826 is configured to at least
partially
enclose the lighting assembly 820, such that the cover 826 directs the fluid
through the
lighting assembly 820 and over the LED assembly 822. Additionally, the cover
826 may
include clear, transparent, and/or semi-transparent materials such that the
light emitted by
the LED assembly 822 may pass through the cover 826 (e.g., after passing
through the
fluid) and outwardly from the cover 826. For example, the cover 826 may be
formed of a
clear plastic and/or glass (e.g., borosilicate glass). In certain embodiments,
the cover 826
may include poly(methyl methacrylate) ("PMMA") and/or other acrylics and/or
other
materials described herein.
100771 The chassis 824 includes a fluid inlet 830 configured to receive the
fluid flowing
along the cooling circuit 110 (e.g., as indicated by arrow 832) and a fluid
outlet 834
configured to flow the fluid from the chassis 823 to the cooling circuit 110
(e.g., as
indicated by arrow 836) (although the fluid direction may be reversed such
that the fluid
enters through the fluid outlet 834, for example, and exits through the fluid
inlet 832).
Additionally, the chassis 824 includes a base 840 and a cylinder 842 extending
from the
base 840. The base 840 includes the fluid inlet 830 and the fluid outlet 834.
In certain
embodiments, the LED assembly 822 and/or the chassis 824 may be included in
the lighting
assembly and/or LED assembly of FIGS. 2-13.
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100781 The LED assembly 822 includes LEDs 850 mounted to a PCB 852. The PCB
852
is mounted to the chassis 824 via connections 854. For example, the PCB 852
includes a
tab 856 extending over a ledge 858 of the chassis 824. The connections 854
secure the
LED assembly 822 to the ledge 858. Additionally, the connections 854 may be
electrical
connections configured to provide power and/or electrical connections to the
LEDs 850.
In certain embodiments, the PCB 852 may include an additional tab 856 disposed
generally
opposite the illustrated tab 856 and configured to mount to an additional
ledge 858 of the
chassis 824. However, the additional tab 856 and the additional ledge 858 are
omitted in
FIG. 14 for purposes of clarity.
[0079] The LEDs 850 of the LED assembly 822 are configured to emit light
outwardly
through the fluid flowing between the LED assembly 822 and the cover 826
(e.g., through
an upper passage 860 of the cooling system 100) and through the cover 826. In
some
embodiments, the cover 826 enclosing the fluid may be acrylic, polycarbonate,
glass (e.g.,
borosilicate glass), or another material having a refractive index between
about 1.44 ¨ 1.5.
Additionally, the refractive index of the LEDs 850 (e.g., the silicone), the
fluid, and/or the
cover 826 may generally be matched (e.g., within a difference threshold).
[0080] The cooling system 100 is configured to flow the fluid into the fluid
inlet 832, into
the upper passage 860 extending between the LED assembly 822 and the cover 826
(e.g.,
as indicated by arrow 862), and into a lower passage 864 extending between the
LED
assembly 822 and the base 840 of the chassis 824 (e.g., as indicated by arrow
866). The
fluid is configured to absorb heat generated by the LED assembly 822 (e.g.,
due to
operation of the LEDs 850 and the PCB 852 and the light emitted by the LEDs
850) as the
fluid flow through the upper passage 860 and the lower passage 864.
Additionally, because
the fluid is generally transparent and/or semi-transparent (e.g., the fluid
has a refractive
index generally between 1.4-1.5), the fluid may have minimal/no effects on the
light
emitted from the LED assembly 822 and through the fluid. As such, the fluid
may actively
cool the LED assembly 822 during operation of the LED assembly 822 with little
to no
effect on a quality of light emitted from the LED assembly 822.
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[0081] The cooling system 100 is configured to flow the fluid from the upper
passage 860
and into the fluid outlet 834, as indicated by arrow 870, and from the lower
passage 864
into the fluid outlet 834, as indicated by arrow 872. After flowing the fluid
over the LED
assembly 822 and into the fluid outlet 834, the pump 108 circulates the fluid
through a heat
exchanger 106 of the cooling system 100, for example, to cool the fluid.
[0082] FIG. 15 is a perspective view of the lighting assembly 820 of FIG.
14. As
described above, the cooling system 100 is configured to circulate the fluid
into the fluid
inlet 830 of the chassis 824, over the LED assembly 822 of the lighting
assembly 820, and
through the fluid outlet 834, thereby cooling the LED assembly 822.
Accordingly, the
lighting assembly 820 of FIGS. 14 and 15 provides a front emission
configuration of a
lighting assembly and LED assembly that may be cooled via the cooling system
100.
[0083] FIG. 16 is a flow diagram of a method 900 for controlling the
cooling system
100 of FIG. 1. For example, the method 900, or portions thereof, may be
performed by the
controller 120 of the cooling system 100. The method 900 begins at block 902,
where the
temperature at an LED assembly (e.g., the LED assembly 102/196) is measured.
The
sensor 121 may measure the temperature and output a signal (e.g., an input
signal to the
controller 120) indicative of the temperature at or adjacent to the LED
assembly (e.g., a
temperature at a surface of the LED assembly, a temperature of the fluid
adjacent to and/or
flowing over the LED assembly, a temperature at a surface of the enclosure
104/198, etc.).
The controller 120 may receive the signal indicative of the temperature.
[0084] At block 904, the temperature at the LED assembly is determined. Block
904 may
be performed in addition to or in place of block 902. For example, block 902
may be
omitted from the method 900, and the sensor 121 may be omitted from the
cooling system
100. The controller 120 may be configured to determine the temperature at the
LED
assembly based on whether the LED assembly, or portions thereof, are emitting
light and
based on an amount of time that the LED assembly , or the portions thereof,
have been
emitting light. As generally described above, the controller 120 may be
configured to
control the LED assembly (e.g., by controlling which LED arrays 182 are
emitting light, a
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duration that the LED arrays 182 emit light, an intensity of the light emitted
by the LED
arrays 182, etc.). Based on the control actions, the controller 120 may
determine/estimate
the temperature at the LED assembly (e.g., the temperature at the surface of
the LED
assembly 102/196, the temperature of the fluid adjacent to and/or flowing over
the LED
assembly 102/196, the temperature at the surface of the enclosure 104/198,
etc.).
[0085] At block 906, operating parameter(s) of the cooling system 100 are
adjusted based
on the temperature at the LED assembly (e.g., the temperature measured at
block 902
and/or determined at block 904). For example, the controller 120 may output a
signal (e.g.,
an output signal) to the pump 108 indicative of instructions to adjust the
flowrate of fluid
through the cooling circuit 110. Additionally or alternatively, the controller
120 may
output a signal to a heat exchanger (e.g., the heat exchanger 106/601)
indicative of
instructions to adjust a flow rate of air flowing over a radiator of the heat
exchanger (e.g.,
by outputting a signal to fans of the heat exchanger 106/601 indicative of
instructions to
adjust a rotational speed of the fans to adjust the flow rate of air). In
certain embodiments,
the controller 120 may control the LED assembly based on the temperature at
the LED
assembly, such as by reducing a number of LED arrays emitting light and/or to
prevent
overheating of the LED assembly.
[0086] In certain embodiments, the controller 120 may compare the temperature
at the
LED assembly to a target temperature and determine whether a difference
between the
temperature (e.g., a measured and/or determined temperature at the LED
assembly
102/196) and the target temperature is greater than a threshold value. Based
on the
difference exceeding the threshold value, the controller 120 may control the
operating
parameters of the cooling system 100 described above. As such, the controller
120 may
reduce certain control actions performed by the cooling system 100 based on
minor
temperature fluctuations and/or may reduce an amount of air flow and/or power
used by
the heat exchanger to cool the fluid. The controller 120 may receive an input
indicative of
the target temperature (e.g., from an operator of the cooling system 100)
and/or may
determine the target temperature based on a type of LED included in the LED
assembly, a
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UN 10006
type of fluid circulating through the cooling system 100, a material of the
enclosure, a
material of the tower of the LED assembly, a size of the LED assembly and/or
the cooling
system 100 generally, or a combination thereof.
[0087] After completing block 906, the method 900 returns to block 902 and the
next
temperature at the LED assembly is measured. Alternatively, the method 900 may
return
to block 904, and the next temperature at the LED assembly may be determined.
As such,
blocks 902-906 of the method 900 may be iteratively performed by the
controller 120
and/or by the cooling system 100 generally to facilitate cooling of the LED
assembly and
the enclosure.
[0088] While only certain features of the disclosure have been illustrated and
described
herein, many modifications and changes will occur to those skilled in the art.
It is,
therefore, to be understood that the appended claims are intended to cover all
such
modifications and changes as fall within the true spirit of the disclosure.
[0089] The techniques presented and claimed herein are referenced and applied
to material
objects and concrete examples of a practical nature that demonstrably improve
the present
technical field and, as such, are not abstract, intangible or purely
theoretical. Further, if
any claims appended to the end of this specification contain one or more
elements
designated as "means for [perform]ing [a function]..." or "step for
[perform]ing [a
function]...", it is intended that such elements are to be interpreted under
35 U.S.C.
112(f). However, for any claims containing elements designated in any other
manner, it is
intended that such elements are not to be interpreted under 35 U.S.C. 112(f).
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