Patent Publication Number: US-2020288553-A1

Title: Simplified electronic protection circuit for LED luminaires for horticultural applications

Description:
COPYRIGHT AND TRADEMARK NOTICE 
     This application includes material which is subject or may be subject to copyright and/or trademark protection. The copyright and trademark owner(s) has no objection to the facsimile reproduction by any of the patent disclosure, as it appears in the Patent and Trademark Office files or records, but otherwise reserves all copyright and trademark rights whatsoever. 
     BACKGROUND OF THE INVENTION 
     (1) Field of the Invention 
     The invention generally relates to electronic protection circuits. More particularly, the invention relates to the design, manufacture and use of simplified electronic protection circuits sometimes used in horticultural applications. 
     (2) Description of the Related Art 
     The use of LED luminaires and use of regulated power supplies are known in the prior art and have become over evolved and an efficient over engineering for the needs of horticultural uses. 
     In the related art, electronic driver circuits for LED lighting have evolved from the requirements of the lighting industry, as applied to enable humans to view objects, as by far the largest market segment for LEDs. In human viewing related applications, there is a critical for light quality to be carefully controlled and maintained to insure high quality illumination for illuminating products such as food and clothing and to maintain ambient conditions for space lighting. LED manufacturers go to great lengths to assure uniform performance in their products. In addition, in traditional LED applications, it is well known that the color spectrum and intensity of LEDs varies critically with the amount of current passing through the device, thus causing the related art to design ever increasingly complicated systems of power regulation. 
     As a result, the human viewing design paradigm for LED luminaires has evolved an electronic architecture designed to maintain precise long-term control of the current supplied to LEDs in the fixture. Typically this design incorporates at the first level a highly regulated constant voltage power supply, mainly incorporating “switching power supply” technology. The output of this power supply then powers a second level of electronic circuitry that controls the current to the LEDs, which may be arranged in several arrays or “strings”. Finally the output of the current controlling circuitry is connected to the LED array, possible on a separate circuit board from the driver. 
     This prior art architecture functions well for the lighting needs of human viewers and consequently has been adapted widely in the lighting industry. However, the multiplicity of layers results in a complex and costly system. 
     The related art eschews the less stringent needs of horticultural applications, wherein the main objective of the lighting system is to provide photons to the plant to be used in the process of photosynthesis, which includes nutrient production and plant regulation. The molecules responsible for these two processes absorb photons over a relatively broad region of the light spectrum, generally between 400 nm and 700 nm. LEDs have found favor in this industry as a blend of colors that efficiently drive the process and can be configured from monochromatic LEDs. For example, it is believed that red photons at about 660 nm and blue photons at 450 nm are well suited for driving the photosynthesis process of the chlorophyll molecules. 
     LEDs operating monochromatically typically produce output spectra with a full-width half-maximum (FWHM) of 25 nm. The variation in the peak emission wavelength of the LEDs also varies within about 20 nm. In addition, as the current driving the LEDs varies, the center wavelength can also shift. Fortunately the absorption characteristics of the chlorophyll molecule exhibit a broad absorption band with a half-width of 70 nm or more. The result is that the plants are not that sensitive to the exact wavelength being absorbed in their production. This is primarily because they have evolved to use the photons from the broad spectrum of the sun. 
     Consequently, incorporating the complicated electronic architecture from the lighting industry into a horticultural lighting is not necessary and indeed increases cost. What is needed is the simplest circuit that addresses the needs of the LEDs. What are those needs? Simply put, the LED needs to have a circuit that limits the maximum current that passes through it and that protects the LEDs from overheating if the cooling system shuts down or fails. LEDs are not sensitive to variations in current and plants are not sensitive to minor fluctuations in the light intensity. The phenomenon of “flicker” which is extremely serious in lighting has no bearing in a horticultural light, other than the possible irritation of humans tending to the plants. 
     Thus, there is a need in the art for the presently disclosed embodiments that use simplified designs in power management and system protection that comport with the more hardy lighting requirements of horticulture. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention overcomes shortfalls in the related art by presenting an unobvious and unique combination, configuration and use of components and designs to produce cost effective lighting systems that take advantage of the more robust tolerances of plant life. 
     The known related art fails to disclose, suggest or teach the use of the disclosed electrical power systems, electrical circuits and other disclosed components that may include the use of a supply voltage in the low voltage DC range (less than 60 VDC). Most of the circuits described above as within the related or prior art are powered by 120-240 VAC power which is much more dangerous, especially in a greenhouse environment which may involve workers standing in ground water while touching fixtures. The presently disclosed designs overcome this prior art short fall and may include designs that incorporate a plurality of small circuits employing 10 to 20 LEDs. Each small circuit may be protected by its own simple circuit that uses fewer than 10 inexpensive elements. In the event that one of the small circuits should fail, operation of the balance of the circuits is unaffected. A typical fixture of 1000 watts may incorporate  40  of the small circuits. 
     Further advantages over the prior art are achieved my use circuits that may comprise an electronic switch (MOSFET), which is controlled by a pair of transistors. One transistor senses the current by means of a current-sensing resistor. The other transistor senses the temperature of the circuit board by means of a resister with a high sensitivity to temperature (a thermistor). This circuit was perfected by numerous iterations of test circuits and has been incorporated in hundreds of LED fixtures successfully. 
     The presently disclosed embodiments may include electrical current conditioning systems which provide desired currently signals to drive one or more LEDs within tolerances acceptable for the growth of plants. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of a current conditioning system. 
         FIG. 2  is a circuit diagram of a first current conditioning circuit, which corresponds to the current conditioning system of  FIG. 1 . 
         FIG. 3  is a circuit diagram of a second current conditioning circuit, which corresponds to the current conditioning system of  FIG. 1 . 
         FIG. 4  is a front view of a first LED array module. 
         FIG. 5  is a front view of a second LED array module. 
         FIG. 6  is a side view of the LED array module of  FIG. 4  showing a first LED carried by a first circuit board. 
         FIG. 7  is a side view of the LED array module of  FIG. 5  showing a second LED carried by a second circuit board. 
         FIGS. 8 and 9  are perspective views of an LED module. 
         FIG. 10  is a side view of the LED module of  FIGS. 8 and 9  carrying a plurality of the LED array modules of  FIG. 4 . 
         FIG. 11  is a side view of the LED module of  FIGS. 8 and 9  carrying a plurality of the LED array modules of  FIG. 5 . 
     
    
    
     These and other aspects of the present invention will become apparent upon reading the following detailed description in conjunction with the associated drawings. 
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
     The following detailed description is directed to certain specific embodiments of the invention. However, the invention can be embodied in a multitude of different ways as defined and covered by the claims and their equivalents. In this description, reference is made to the drawings wherein like parts are designated with like numerals throughout. 
     Unless otherwise noted in this specification or in the claims, all of the terms used in the specification and the claims will have the meanings normally ascribed to these terms by workers in the art. 
     Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising” and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in a sense of “including, but not limited to.” Words using the singular or plural number also include the plural or singular number, respectively. Additionally, the words “herein,” “above,” “below,” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. 
     The embodiments disclosed herein may include a current conditioning system for controlling the current flow through a light emitting diode (LED). The current conditioning system operates in response to applying a low voltage. The low voltage can be of many different values, such as about 60 VDC. The current conditioning system can drive one or more discrete LED devices, and it can drive LED strip lighting. The current conditioning system can drive one or more LED array modules. In some embodiments, the current conditioning system includes ten or more LED array modules. In some embodiments, each LED array module includes a current conditioning circuit carried on the same circuit board as the LEDs. 
     The current conditioning circuit controls the amount of current that flows through the LEDs. The current conditioning system still operates if one or more of the LED array modules fail to operate. The current conditioning system protects the LEDs from overheating if a cooling system shuts down or fails. 
       FIG. 1  is a block diagram of a current conditioning system  100 . In this embodiment, the current conditioning system  100  includes an LED array  101  in communication with a switching circuit  103 . The switching circuit  103  is in communication with a thermal-sensing circuit  105  and current-sensing circuit  106 . The LED array  101  is connected to a terminal  138 , and the thermal-sensing circuit  105  and current-sensing circuit  106  are connected to a current return  137 . It should be noted that the currents and voltages of the current conditioning system  100  are established in response to applying a voltage VCC to the terminal  138 , wherein the voltage VCC is referenced at the current return  137 . The voltage VCC can have many different values. In this embodiment, the voltage VCC is less than or equal to 60 VDC. It should be noted that the value of the voltage VCC depends on the power requirements of the current conditioning system  100 . 
     In operation, a switching current ISW flows through the LED array  101  in response to the switching circuit  103  having an ON condition. The LED array  101  provides light in response to enough of the switching current ISW flowing therethrough. The LED array  101  provides light in response to the switching current ISW being driven above a threshold current. In general, the LED array  101  provides light in response to the switching current ISW being greater than or equal to the threshold current. The switching current ISW does not flow through the LED array  101  in response to the switching circuit  103  having an OFF condition. The LED array  101  does not provide light in response to not enough of the switching current ISW flowing therethrough. The LED array  101  does not provide light in response to the switching current ISW being driven below the threshold current. In general, the LED array  101  does not provide light in response to the switching current ISW being less than the threshold current. 
     It should be noted that the switching circuit  103  is repeatably moveable between the ON and OFF conditions. The switching circuit  103  can be moved between the ON and OFF conditions in many different ways. In this embodiment, the switching circuit  103  is moved between the ON and OFF conditions in response to a temperature indication. The switching circuit  103  moves to the ON condition in response to the temperature indication being below a predetermined temperature value. The switching circuit  103  moves to the OFF condition in response to the temperature indication being above the predetermined temperature value. 
     In this embodiment, the temperature indication corresponds to the temperature of the thermal-sensing circuit  105 . A thermal-sensing voltage VTC is adjustable in response to adjusting the temperature indication. In one embodiment, the thermal-sensing voltage VTC increases in response to the temperature indication being increased, and the thermal-sensing voltage VTC decreases in response to the temperature indication being decreased. 
     In one situation, the switching circuit  103  has the ON condition in response to the thermal-sensing voltage VTC having a first predetermined voltage threshold value. The switching current ISW increases in response to the switching circuit  103  being driven to the ON condition. The LED array  101  provides more light in response to the switching current ISW increasing. In particular, the LED array  101  provides more light in response to the switching current ISW increasing above the threshold current. 
     In another situation, the switching circuit  103  has the OFF condition in response to the thermal-sensing voltage VTC being less than the first predetermined voltage threshold value. The switching current ISW decreases in response to the switching circuit  103  being driven to the OFF condition. The LED array  101  provides less light in response to the switching current ISW decreasing. In particular, the LED array  101  provides less light in response to the switching current ISW decreasing below the threshold current. In this way, the switching current ISW can be adjusted in response to adjusting the thermal-sensing voltage VTC with the temperature indication. 
     In this embodiment, the switching circuit  103  is moved between the ON and OFF conditions in response to a voltage indication. The switching circuit  103  moves to the ON condition in response to the voltage indication being below a second predetermined voltage threshold value. The switching circuit  103  moves to the OFF condition in response to the voltage indication being above the second predetermined voltage threshold value. It should be noted that the switching circuit  103  can be moved between the ON and OFF conditions in response to other types of indications. For example, in some embodiments, the switching circuit  103  is moved between the ON and OFF conditions in response to a current indication. In some embodiments, the switching circuit  103  is moved between the ON and OFF conditions in response to a power indication. 
     In this embodiment, the voltage indication corresponds to the voltage of the current-sensing circuit  106 . A sensing voltage VSC is adjustable in response to adjusting the current indication. In one embodiment, the sensing voltage VSC increases in response to the current indication being increased, and the sensing voltage VSC decreases in response to the current indication being decreased. 
     In one situation, the switching circuit  103  has the ON condition in response to the sensing voltage VSC having the second predetermined voltage threshold value. The switching current ISW increases in response to the switching circuit  103  being driven to the ON condition. The LED array  101  provides more light in response to the switching current ISW increasing. In particular, the LED array  101  provides more light in response to the switching current ISW increasing above the second predetermined voltage threshold value. 
     In another situation, the switching circuit  103  has the OFF condition in response to the sensing voltage VSC being less than the second predetermined voltage threshold value. The switching current ISW decreases in response to the switching circuit  103  being driven to the OFF condition. The LED array  101  provides less light in response to the switching current ISW decreasing. In particular, the LED array  101  provides less light in response to the switching current ISW decreasing below the second predetermined voltage threshold value. In this way, the switching current ISW can be adjusted in response to adjusting the sensing voltage VSC with the current indication. 
       FIG. 2  is a circuit diagram of a current conditioning circuit  110 , which corresponds to the current conditioning system  100  of  FIG. 1 . It should be noted that the current conditioning circuit  110  includes the terminal  138  and current return  137 , and is provided power in response to applying the potential difference VCC ( FIG. 1 ) between the terminal  138  and current return  137 . 
     In this embodiment, the current conditioning circuit  110  includes the LED array  101 . The LED array  101  can be of many different types. In this embodiment, the LED array  101  includes an LED which provides light in response to receiving a current. In general, the LED array  101  includes one or more LEDs. In this embodiment, the LED array  101  includes a plurality of LEDs, denoted as LED  120 , LED  121 , LED,  122 , LED  123 , LED  124 , LED,  125 , LED  126 , and LED  127 , wherein the LEDs of the LED array  101  are connected in series. In other embodiments, the LEDs of the LED array  101  are connected in parallel. In some embodiments, the LEDs of the LED array  101  are connected in series-parallel. It should be noted that the positive terminal of the LED  120  is connected to the terminal  138 . Further, the negative terminal of the LED  127  is connected to the switching circuit  103 , as will be discussed in more detail below. 
     In this embodiment, the current conditioning circuit  110  includes the switching circuit  103  in communication with the thermal-sensing circuit  105  and current-sensing circuit  106 . In this embodiment, the switching circuit  103  includes a transistor  136  having a drain terminal connected to the negative terminal of the LED  127 . The transistor  136  includes a source terminal connected to a first terminal of a current-sensing resistor  133 , wherein the current-sensing resistor  133  has a second terminal connected to the current return  137 . The transistor  136  includes a control terminal connected to a first terminal of a biasing resistor  131 , wherein a second terminal of the biasing resistor  131  is connected to the terminal  138 . 
     In this embodiment, the current conditioning circuit  110  includes a transistor  135 , having a base terminal connected to the first terminal of the resistor  133  and the source terminal of the transistor  136 . The transistor  135  includes a collector terminal connected to the first terminal of the biasing resistor  131 . The transistor  135  includes an emitter terminal connected to the current return  137  and the second terminal of the current-sensing resistor  133 . 
     In this embodiment, the current conditioning circuit  110  includes a transistor  134 , having a base terminal connected to the first terminal of the resistor  131  and the source terminal of the transistor  136 . The transistor  134  includes a collector terminal connected to a first terminal of a thermal-sensing resistor  132 , wherein the thermal-sensing resistor  132  includes a second terminal connected to the current return  137 . The transistor  134  includes an emitter terminal connected to the current return  137  and the second terminal of the thermal-sensing resistor  132 . One example of a thermal-sensing resistor is a thermistor. In general, the resistance of the thermal-sensing resistor  132  is adjustable in response to adjusting the temperature thereof. In this embodiment, the resistance of the thermal-sensing resistor  132  increases in response to the temperature increasing. Further, the resistance of the thermal-sensing resistor  132  decreases in response to the temperature decreasing. 
     In this embodiment, the current conditioning circuit  110  includes a biasing resistor  130  with a first terminal connected to the base of the transistor  134  and the first terminal of the thermal-sensing resistor  132 . The biasing resistor  130  includes a second terminal connected to the terminal  138  and the second terminal of the resistor  131 . In this way, the second terminals of the biasing resistors  130  and  131  are connected together. It should be noted that the thermal-sensing circuit  105  includes the biasing resistor  130 , thermal-sensing resistor  132 , and transistor  134 . Further, the current-sensing circuit  106  includes the biasing resistor  131 , current-sensing resistor  133 , and transistor  135 . 
     It should be noted that the switching circuit  103  includes the transistor  136 . The transistor  136  can be of many different types, such as a metal oxide field effect transistor (MOSFET). The thermal-sensing circuit  105  includes the transistor  134 , biasing resistor  130 , and thermal-sensing resistor  132 . The transistor  134  can be of many different types, such as a bipolar junction transistor (BJT). The current-sensing circuit  106  includes the transistor  135 , biasing resistor  131 , and current-sensing resistor  133 . The transistor  135  can be of many different types, such as a bipolar junction transistor (BJT). 
     In operation, the switching current ISW 1  flows through the LED array  101  in response to the switching circuit  103  having an ON condition. The LED array  101  provides light in response to enough of the switching current ISW 1  flowing therethrough. The LED array  101  provides light in response to the switching current ISW 1  being driven above a threshold current. In general, the LED array  101  provides light in response to the switching current ISW 1  being greater than or equal to the threshold current. The switching current ISW 1  does not flow through the LED array  101  in response to the switching circuit  103  having an OFF condition. The LED array  101  does not provide light in response to not enough of the switching current ISW 1  flowing therethrough. The LED array  101  does not provide light in response to the switching current ISW 1  being driven below the threshold current. In general, the LED array  101  does not provide light in response to the switching current ISW 1  being less than the threshold current. 
     It should be noted that the transistor  136  is repeatably moveable between the ON and OFF conditions. The transistor  136  can be moved between the ON and OFF conditions in many different ways. In this embodiment, the transistor  136  is moved between the ON and OFF conditions in response to the temperature indication. The transistor  136  moves to the ON condition in response to the temperature indication being below the predetermined temperature value. The transistor  136  moves to the OFF condition in response to the temperature indication being above the predetermined temperature value. 
     In this embodiment, the temperature indication corresponds to the temperature of the thermal-sensing resistor  132 . The thermal-sensing voltage VTC 1 , provided to the transistor  134 , is adjustable in response to adjusting the temperature indication. In one embodiment, the thermal-sensing voltage VTC 1  increases in response to the temperature indication being increased, and the thermal-sensing voltage VTC 1  decreases in response to the temperature indication being decreased. 
     In one situation, the transistor  136  has the ON condition in response to the thermal-sensing voltage VTC 1  being driven to a value greater than or equal to a third predetermined voltage threshold value. The switching current ISW 1  increases in response to the transistor  136  being driven to the ON condition. The LED array  101  provides more light in response to the switching current ISW 1  increasing. In particular, the LED array  101  provides more light in response to the switching current ISW 1  increasing above the threshold current. 
     In another situation, the transistor  136  has the OFF condition in response to the thermal-sensing voltage VTC 1  being less than the third predetermined voltage threshold value. The switching current ISW 1  decreases in response to the transistor  136  being driven to the OFF condition. The LED array  101  provides less light in response to the switching current ISW 1  decreasing. In particular, the LED array  101  provides less light in response to the switching current ISW 1  decreasing below the threshold current. In this way, the switching current ISW 1  can be adjusted in response to adjusting the thermal-sensing voltage VTC 1  with the temperature indication. 
     It should be noted that the transistor  134  is moved between ON and OFF conditions in response to adjusting the thermal-sensing voltage VTC 1 . Further, the transistor  136  is moved between the ON and OFF conditions in response to adjusting a voltage V 1  at the control terminal of the transistor  136 . 
     The voltage V 1  is driven to the potential of the current return  137  in response to the transistor  134  having an ON condition. The transistor  136  is moved to the OFF condition in response to driving the voltage V 1  to the potential of the current return  137 . The voltage V 1  is driven away from the potential of the current return  137  in response to the transistor  134  having an OFF condition. The transistor  136  is moved to the ON condition in response to driving the voltage V 1  away from the potential of the current return  137 . 
     In this embodiment, the transistor  136  is moved between the ON and OFF conditions in response to the voltage indication. The transistor  136  moves to the ON condition in response to the voltage indication being below the second predetermined voltage threshold value. The transistor  136  moves to the OFF condition in response to the voltage indication being above the second predetermined voltage threshold value. 
     In this embodiment, the voltage indication corresponds to the voltage of the current-sensing resistor  133 . The sensing voltage VSC 1 , provided to the transistor  135  by the current-sensing circuit  106 , is adjustable in response to adjusting the current indication. In one embodiment, the sensing voltage VSC 1  increases in response to the current indication being increased, and the sensing voltage VSC 1  decreases in response to the current indication being decreased. 
     In one situation, the switching circuit  103  has the ON condition in response to the sensing voltage VSC 1  having the second predetermined voltage threshold value. The switching current ISW 1  increases in response to the switching circuit  103  being driven to the ON condition. The LED array  101  provides more light in response to the switching current ISW 1  increasing. In particular, the LED array  101  provides more light in response to the switching current ISW 1  increasing above the second predetermined voltage threshold value. 
     In another situation, the switching circuit  103  has the OFF condition in response to the sensing voltage VSC 1  being less than the second predetermined voltage threshold value. The switching current ISW 1  decreases in response to the switching circuit  103  being driven to the OFF condition. The LED array  101  provides less light in response to the switching current ISW 1  decreasing. In particular, the LED array  101  provides less light in response to the switching current ISW 1  decreasing below the second predetermined voltage threshold value. In this way, the switching current ISW 1  can be adjusted in response to adjusting the sensing voltage VSC 1  with the current indication. 
     It should be noted that the transistor  135  is moved between ON and OFF conditions in response to adjusting the sensing voltage VSC 1 . Further, the transistor  136  is moved between the ON and OFF conditions in response to adjusting the voltage V 1  at the control terminal of the transistor  136 . 
     The voltage V 1  is driven to the potential of the current return  137  in response to the transistor  135  having an ON condition. The transistor  136  is moved to the OFF condition in response to driving the voltage V 1  to the potential of the current return  137 . The voltage V 1  is driven away from the potential of the current return  137  in response to the transistor  134  having an OFF condition. The transistor  136  is moved to the ON condition in response to driving the voltage V 1  away from the potential of the current return  137 . 
       FIG. 3  is a circuit diagram of a current conditioning circuit  111 , which corresponds to the current conditioning system  100  of  FIG. 1 . It should be noted that the current conditioning circuit  111  includes a terminal  168  and current return  167 , and is provided power in response to applying the potential difference VCC ( FIG. 1 ) between the terminal  168  and current return  167 . 
     In this embodiment, the current conditioning circuit  111  includes the LED array  141 . The LED array  141  can be of many different types. In this embodiment, the LED array  141  includes an LED which provides light in response to receiving a current. In general, the LED array  141  includes one or more LEDs. In this embodiment, the LED array  141  includes a plurality of LEDs, denoted as LED  150 , LED  151 , LED,  152 , LED  153 , LED  154 , LED,  155 , LED  156 , and LED  157 , wherein the LEDs of the LED array  141  are connected in series. In other embodiments, the LEDs of the LED array  141  are connected in parallel. In some embodiments, the LEDs of the LED array  141  are connected in series-parallel. It should be noted that the positive terminal of the LED  150  is connected to the terminal  168 . Further, the negative terminal of the LED  147  is connected to the switching circuit  143 , as will be discussed in more detail below. 
     In this embodiment, the current conditioning circuit  111  includes the switching circuit  143  in communication with the thermal-sensing circuit  145  and current-sensing circuit  146 . In this embodiment, the switching circuit  143  includes a transistor  166  having a drain terminal connected to the negative terminal of the LED  157 . The transistor  166  includes a source terminal connected to a first terminal of a current-sensing resistor  163 , wherein the current-sensing resistor  163  has a second terminal connected to the current return  167 . The transistor  166  includes a control terminal connected to a first terminal of a biasing resistor  161 , wherein a second terminal of the biasing resistor  161  is connected to the terminal  168 . 
     In this embodiment, the current conditioning circuit  111  includes a transistor  165 , having a base terminal connected to the first terminal of the resistor  163  and the source terminal of the transistor  166 . The transistor  165  includes a collector terminal connected to the first terminal of the biasing resistor  161 . The transistor  165  includes an emitter terminal connected to the current return  167  and the second terminal of the current-sensing resistor  163 . 
     In this embodiment, the current conditioning circuit  111  includes a transistor  164 , having a base terminal connected to the first terminal of the resistor  161  and the source terminal of the transistor  166 . The transistor  164  includes a collector terminal connected to a first terminal of a thermal-sensing resistor  162 , wherein the thermal-sensing resistor  162  includes a second terminal connected to the current return  167 . The transistor  164  includes an emitter terminal connected to the current return  167  and the second terminal of the thermal-sensing resistor  162 . One example of a thermal-sensing resistor is a thermistor. In general, the resistance of the thermal-sensing resistor  162  is adjustable in response to adjusting the temperature thereof. In this embodiment, the resistance of the thermal-sensing resistor  162  increases in response to the temperature increasing. Further, the resistance of the thermal-sensing resistor  162  decreases in response to the temperature decreasing. 
     In this embodiment, the current conditioning circuit  111  includes a biasing resistor  160  with a first terminal connected to the base of the transistor  164  and the first terminal of the thermal-sensing resistor  162 . The biasing resistor  160  includes a second terminal connected to the terminal  168  and the second terminal of the resistor  161 . In this way, the second terminals of the biasing resistors  160  and  161  are connected together. It should be noted that the thermal-sensing circuit  145  includes the biasing resistor  160 , thermal-sensing resistor  162 , and transistor  164 . Further, the current-sensing circuit  146  includes the biasing resistor  161 , current-sensing resistor  163 , and transistor  165 . 
     It should be noted that the switching circuit  143  includes the transistor  166 . The transistor  166  can be of many different types, such as a metal oxide field effect transistor (MOSFET). The thermal-sensing circuit  145  includes the transistor  164 , biasing resistor  160 , and thermal-sensing resistor  162 . The transistor  164  can be of many different types, such as a bipolar junction transistor (BJT). The current-sensing circuit  146  includes the transistor  165 , biasing resistor  161 , and current-sensing resistor  163 . The transistor  165  can be of many different types, such as a bipolar junction transistor (BJT). 
     In operation, the switching current ISW 2  flows through the LED array  141  in response to the switching circuit  143  having an ON condition. The LED array  141  provides light in response to enough of the switching current ISW 2  flowing therethrough. The LED array  141  provides light in response to the switching current ISW 2  being driven above a threshold current. In general, the LED array  141  provides light in response to the switching current ISW 2  being greater than or equal to the threshold current. The switching current ISW 2  does not flow through the LED array  141  in response to the switching circuit  143  having an OFF condition. The LED array  141  does not provide light in response to not enough of the switching current ISW 2  flowing therethrough. The LED array  141  does not provide light in response to the switching current ISW 2  being driven below the threshold current. In general, the LED array  141  does not provide light in response to the switching current ISW 2  being less than the threshold current. 
     It should be noted that the transistor  166  is repeatably moveable between the ON and OFF conditions. The transistor  166  can be moved between the ON and OFF conditions in many different ways. In this embodiment, the transistor  166  is moved between the ON and OFF conditions in response to the temperature indication. The transistor  166  moves to the ON condition in response to the temperature indication being below the predetermined temperature value. The transistor  166  moves to the OFF condition in response to the temperature indication being above the predetermined temperature value. 
     In this embodiment, the temperature indication corresponds to the temperature of the thermal-sensing resistor  162 . The thermal-sensing voltage VTC 2 , provided to the transistor  164 , is adjustable in response to adjusting the temperature indication. In one embodiment, the thermal-sensing voltage VTC 2  increases in response to the temperature indication being increased, and the thermal-sensing voltage VTC 2  decreases in response to the temperature indication being decreased. 
     In one situation, the transistor  166  has the ON condition in response to the thermal-sensing voltage VTC 2  being driven to a value greater than or equal to a third predetermined voltage threshold value. The switching current ISW 2  increases in response to the transistor  166  being driven to the ON condition. The LED array  141  provides more light in response to the switching current ISW 2  increasing. In particular, the LED array  141  provides more light in response to the switching current ISW 1  increasing above the threshold current. 
     In another situation, the transistor  166  has the OFF condition in response to the thermal-sensing voltage VTC 2  being less than the third predetermined voltage threshold value. The switching current ISW 2  decreases in response to the transistor  166  being driven to the OFF condition. The LED array  141  provides less light in response to the switching current ISW 2  decreasing. In particular, the LED array  141  provides less light in response to the switching current ISW 2  decreasing below the threshold current. In this way, the switching current ISW 2  can be adjusted in response to adjusting the thermal-sensing voltage VTC 2  with the temperature indication. 
     It should be noted that the transistor  164  is moved between ON and OFF conditions in response to adjusting the thermal-sensing voltage VTC 2 . Further, the transistor  166  is moved between the ON and OFF conditions in response to adjusting a voltage V 2  at the control terminal of the transistor  166 . 
     The voltage V 2  is driven to the potential of the current return  167  in response to the transistor  164  having an ON condition. The transistor  166  is moved to the OFF condition in response to driving the voltage V 2  to the potential of the current return  167 . The voltage V 2  is driven away from the potential of the current return  167  in response to the transistor  164  having an OFF condition. The transistor  166  is moved to the ON condition in response to driving the voltage V 2  away from the potential of the current return  167 . 
     In this embodiment, the transistor  166  is moved between the ON and OFF conditions in response to the voltage indication. The transistor  166  moves to the ON condition in response to the voltage indication being below the second predetermined voltage threshold value. The transistor  166  moves to the OFF condition in response to the voltage indication being above the second predetermined voltage threshold value. 
     In this embodiment, the voltage indication corresponds to the voltage of the current-sensing resistor  163 . The sensing voltage VSC 2 , provided to the transistor  165  by the current-sensing circuit  146 , is adjustable in response to adjusting the current indication. In one embodiment, the sensing voltage VSC 2  increases in response to the current indication being increased, and the sensing voltage VSC 2  decreases in response to the current indication being decreased. 
     In one situation, the switching circuit  143  has the ON condition in response to the sensing voltage VSC 2  having the second predetermined voltage threshold value. The switching current ISW 2  increases in response to the switching circuit  143  being driven to the ON condition. The LED array  141  provides more light in response to the switching current ISW 2  increasing. In particular, the LED array  141  provides more light in response to the switching current ISW 2  increasing above the second predetermined voltage threshold value. 
     In another situation, the switching circuit  143  has the OFF condition in response to the sensing voltage VSC 2  being less than the second predetermined voltage threshold value. The switching current ISW 2  decreases in response to the switching circuit  143  being driven to the OFF condition. The LED array  141  provides less light in response to the switching current ISW 2  decreasing. In particular, the LED array  141  provides less light in response to the switching current ISW 2  decreasing below the second predetermined voltage threshold value. In this way, the switching current ISW 2  can be adjusted in response to adjusting the sensing voltage VSC 2  with the current indication. 
     It should be noted that the transistor  165  is moved between ON and OFF conditions in response to adjusting the sensing voltage VSC 2 . Further, the transistor  166  is moved between the ON and OFF conditions in response to adjusting the voltage V 2  at the control terminal of the transistor  166 . 
     The voltage V 2  is driven to the potential of the current return  167  in response to the transistor  165  having an ON condition. The transistor  166  is moved to the OFF condition in response to driving the voltage V 2  to the potential of the current return  167 . The voltage V 2  is driven away from the potential of the current return  167  in response to the transistor  164  having an OFF condition. The transistor  166  is moved to the ON condition in response to driving the voltage V 2  away from the potential of the current return  167 . 
       FIG. 4  is a front view of a LED array module  115 . In this embodiment, the LED array module  115  includes a circuit board  116 , which carries the LED array  101  and current conditioning circuit  110 , as shown in  FIG. 2 . In this embodiment, the LEDs of the LED array  101  are spaced apart from each other along the length of the circuit board  116 . It should be noted that, in some embodiments, the LEDs of the LED array  101  are discrete components. In other embodiments, the LED array  101  is an LED strip. 
       FIG. 5  is a front view of a LED array module  117 . In this embodiment, the LED array module  117  includes a circuit board  118 , which carries the LED array  141  and current conditioning circuit  111 , as shown in  FIG. 3 . In this embodiment, the LEDs of the LED array  141  are spaced apart from each other along the length of the circuit board  118 . It should be noted that, in some embodiments, the LEDs of the LED array  141  are discrete components. In other embodiments, the LED array  141  is an LED strip. 
       FIG. 6  is a side view of the LED array module  115  showing the LED  120  carried by the circuit board  116 . In this embodiment, the LED  120  includes a housing  129  which carries a lens  128 . The circuit board  116  includes a surface  108  opposed to the LED  120 . 
       FIG. 7  is a side view of the LED array module  117  showing the LED  150  carried by the circuit board  118 . In this embodiment, the LED  150  includes a housing  159  which carries a lens  158 . The circuit board  116  includes a surface  109  opposed to the LED  150 . 
       FIGS. 8 and 9  are perspective views of an LED module  260 . In this embodiment, the LED module  260  includes an LED support structure  261 , which extends between opposed ends  265  and  266 . A channel  264  extends through the LED support structure  261  between the opposed ends  265  and  266 . The LED support structure  261  includes a support surface  262  and  263 . The surfaces  262  and  263  extend along the length of the LED support structure  261  between the opposed ends  265  and  266 . 
       FIG. 10  is a side view of the LED module  260  of  FIGS. 8 and 9 . In this embodiment, a plurality of LED array modules  115  are coupled to the surface  262 . In this particular embodiment, five LED array modules  115  are coupled to the surface  262  for illustrative purposes. The surface  108  of the circuit board  116  ( FIG. 6 ) is coupled to the surface  262  of the LED support structure  261  ( FIG. 9 ). 
       FIG. 11  is a side view of the LED module  260  of  FIGS. 8 and 9 . In this embodiment, a plurality of LED array modules  117  are coupled to the surface  263 . In this particular embodiment, five LED array modules  117  are coupled to the surface  263  for illustrative purposes. The surface  109  of the circuit board  116  ( FIG. 8 ) is coupled to the surface  263  of the LED support structure  261  ( FIG. 8 ). 
     It should be noted that a material can be flowed through the channel  264  to decrease the amount of heat proximate to the LED module  260 . The fluid can be of many different types, such as a gas. The gas can be of many different types, such as air. The fluid can be a liquid, such as water. In one situation, the heat flows from the LED array  101  and through the circuit board  116 . The heat flows through the surfaces  108  and  262 , wherein the fluid moves the heat through the channel  264 . The fluid and heat can be flowed through the ends  265  and/or  266 . In one situation, the heat flows from the LED array  141  and through the circuit board  118 . The heat flows through the surfaces  109  and  263 , wherein the fluid moves the heat through the channel  264 . The fluid and heat can be flowed through the ends  265  and/or  266 . In this way, the operating temperature of the LED module  260  is decreased. 
     The embodiments of the invention described herein are exemplary and numerous modifications, variations and rearrangements can be readily envisioned to achieve substantially equivalent results, all of which are intended to be embraced within the spirit and scope of the invention as defined in the appended claims. 
     The above detailed description of embodiments of the invention is not intended to be exhaustive or to limit the invention to the precise form disclosed above. While specific embodiments of, and examples for, the invention are described above for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize. For example, while steps are presented in a given order, alternative embodiments may perform routines having steps in a different order. The teachings of the invention provided herein can be applied to other systems, not only the systems described herein. The various embodiments described herein can be combined to provide further embodiments. These and other changes can be made to the invention in light of the detailed description. 
     All the above references and U.S. patents and applications are incorporated herein by reference. Aspects of the invention can be modified, if necessary, to employ the systems, functions and concepts of the various patents and applications described above to provide yet further embodiments of the invention. 
     These and other changes can be made to the invention in light of the above detailed description. In general, the terms used in the following claims, should not be construed to limit the invention to the specific embodiments disclosed in the specification, unless the above detailed description explicitly defines such terms. Accordingly, the actual scope of the invention encompasses the disclosed embodiments and all equivalent ways of practicing or implementing the invention under the claims. 
     While certain aspects of the invention are presented below in certain claim forms, the inventors contemplate the various aspects of the invention in any number of claim forms. 
     The disclosed embodiments may include the following items 
     1. A current conditioning system ( 100 ), comprising: 
     an LED support structure ( 261 ) with a channel ( 264 ) extending therethrough; and 
     a first LED array module ( 115 ) carried on a first surface ( 108 ) of the LED support structure ( 261 ), wherein the first LED array module ( 115 ) includes a first LED array ( 101 ) and a first current conditioning circuit ( 110 ) which adjusts the amount of current flowing through the first LED array ( 101 ) in response to a first temperature indication. 
     2. The system of 1, wherein the first temperature indication is adjustable in response to adjusting the flow of a material through the channel ( 264 ). 
     3. The system of 1, wherein the first current conditioning circuit ( 110 ) includes a first thermal sensing circuit ( 105 ) and a first current sensing circuit ( 106 ). 
     4. The system of 3, wherein the first thermal sensing circuit ( 105 ) adjusts the amount of current flowing through the first LED array ( 101 ) in response to the first temperature indication. 
     5. The system of 3, wherein the first current sensing circuit ( 106 ) adjusts the amount of current flowing through the first LED array ( 101 ) in response to a first voltage indication. 
     6. The system of 3, wherein the first thermal sensing circuit ( 105 ) and first current sensing circuit ( 106 ) adjust the amount of current flowing through the first LED array ( 101 ). 
     7. A current conditioning system ( 100 ), comprising: 
     an LED support structure ( 261 ) with a channel ( 264 ) extending therethrough; 
     a first LED array module ( 115 ) carried on a first surface ( 108 ) of the LED support structure ( 261 ), wherein the first LED array module ( 115 ) includes a first LED array ( 101 ) and a first current conditioning circuit ( 110 ) which adjusts the amount of current flowing through the first LED array ( 101 ) in response to a first temperature indication; and 
     a second LED array module ( 117 ) carried on a second surface ( 109 ) of the LED support structure ( 261 ), wherein the second LED array module ( 117 ) includes a second LED array ( 141 ) and a second current conditioning circuit ( 110 ) which adjusts the amount of current flowing through the second LED array ( 141 ) in response to a second temperature indication. 
     8. The system of 7, wherein the first and second temperature indications are adjustable in response to adjusting the flow of a material through the channel ( 264 ). 
     9. The system of claim  8 , wherein the first current conditioning circuit ( 110 ) includes a first thermal sensing circuit ( 105 ) and a first current sensing circuit ( 106 ). 
     10. The system of claim  9 , wherein the first thermal sensing circuit ( 105 ) adjusts the amount of current flowing through the first LED array ( 101 ) in response to the first temperature indication. 
     11. The system of 8, wherein the second current conditioning circuit ( 111 ) includes a second thermal sensing circuit ( 105 ) and a second current sensing circuit ( 106 ). 
     12. The system of 11, wherein the second thermal sensing circuit ( 105 ) adjusts the amount of current flowing through the second LED array ( 141 ) in response to the second temperature indication. 
     13. The system of 7, wherein the first current sensing circuit ( 106 ) adjusts the amount of current flowing through the first LED array ( 101 ) in response to a first voltage indication. 
     14. The system of 7, wherein the first current sensing circuit ( 106 ) adjusts the amount of current flowing through the first LED array ( 101 ) in response to a first voltage indication. 
     15. A current conditioning system ( 100 ), comprising: 
     an LED support structure ( 261 ) with a channel ( 264 ) extending therethrough; and 
     an LED array module ( 115 ) carried on a surface ( 108 ) of the LED support structure ( 261 ), wherein the LED array module ( 115 ) includes an LED array ( 101 ) and a current conditioning circuit ( 110 ) which adjusts the amount of current flowing through the LED array ( 101 ) in response to a temperature indication. 
     16. The system of 15, wherein the temperature indication is adjustable in response to adjusting the flow of a material through the channel ( 264 ). 
     17. The system of 15, wherein the current conditioning circuit ( 110 ) adjusts the amount of current flowing through the LED array ( 101 ) in response to a voltage indication. 
     18. The system of 15, wherein the current conditioning circuit ( 110 ) includes a thermal sensing circuit ( 105 ) and a current sensing circuit ( 106 ). 
     19. The system of 18, wherein the first thermal sensing circuit ( 105 ) and first current sensing circuit ( 106 ) adjust the amount of current flowing through the first LED array ( 101 ). 
     20. The system of 18, wherein the current conditioning circuit ( 110 ) includes a switching circuit ( 103 ), the thermal sensing circuit ( 105 ) and current sensing circuit ( 106 ) adjusting the amount of current flowing through the switching circuit ( 103 ).