Patent Publication Number: US-2015061498-A1

Title: Temperature Controlled High Output LED Lighting System

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application Ser. No. 61/873,036, filed on Sep. 3, 2013, the entirety of which is hereby expressly incorporated by reference herein. 
    
    
     FIELD 
     The present invention is directed to luminaires and lighting systems and more particularly to high output luminaires and lighting systems employing light emitting diodes (LEDs) and LED modules. 
     BACKGROUND 
     Lighting systems are known that require high intensity light output from lamps. These systems can be used in various indoor lighting applications that require a lot of illumination to brightly illuminate indoor spaces. Outdoor lighting applications that require a lot of illumination include various outdoor entertainment venues, as well as illuminated outdoor public areas such as parks and streets. Other outdoor lighting applications that require a lot of illumination include security and other lighting for commercial and residential buildings. Outdoor lighting with light towers is known for use at construction sites and various outdoor events that require a lot of illumination to brightly illuminate relatively large areas. To cover such relatively large areas, light towers include lights that are mounted to upper ends of tall masts so that light beams from the lights can sufficiently spread across and illuminate such large areas. 
     Most of these indoor and outdoor lighting systems that require high intensity light output from lamps include lamps that are positioned relatively high in the air and thus far from the areas being illuminated. Accordingly, high-power bulbs are required to sufficiently illuminate areas. Such bulbs, including metal halide and other bulbs, can consume large amounts of electrical power. In addition, the quality of the light or its Color Rendering Index (CRI) can produce light that gives the impression of illuminating poorly despite being very bright. 
     Light emitting diodes or LEDs are gaining popularity as lighting sources. Not only do LEDs consume less power, they have a long life, and can produce a better quality light at a lower brightness or lumen level. LEDs for high output usage tended to be provided as LED modules with LEDs mounted to circuit boards. LED modules have stringent maximum temperature operating requirements, above which the circuit boards of the LED modules can be damaged. 
     What is needed is a high brightness or high lumen output lighting system capable of outdoor use that uses LED modules in a manner that produces reliable and stable operation. 
     SUMMARY 
     The present invention is directed to a thermally responsive LED lighting control system that includes a LED module lighting system formed of a plurality of LED modules in close proximity to one another in communication with a controller that controls operation of the LED module lighting system based on temperature to ensure that a minimum amount of light is outputted at all times by LED modules of the LED module lighting system while thermally protecting LED modules of the LED module lighting system. In a preferred LED lighting control system, multiple LED modules of a LED module lighting system are carried by a luminaire or lamp and a sensed or measured temperature of the luminaire or lamp is used by the controller in controlling LED module operation in a manner that maintains a minimum amount of light output from the luminaire or lamp during operation. 
     In one such LED lighting control system, the LED module lighting system of a lamp or luminaire has at least a plurality of pairs, i.e., at least three, LED modules adjacent one another with controller using at least one temperature sensed or measured at or adjacent at least one of the LED modules in controlling operation of at least one of the LED modules to maintain a minimum light output while thermally protecting the modules. In such a preferred LED lighting control system, the LED module lighting system of a lamp or luminaire has at least a plurality of pairs, i.e., at least three, LED modules adjacent one another with the controller using at least one temperature sensed or measured at or adjacent at least one of the LED modules in controlling operation of at least one of the LED modules but less than all of the LED modules of the LED module lighting system to maintain a minimum light output while at the same time thermally protecting the modules. 
     The present invention also is directed to a high output lighting system formed of a plurality of luminaires or lamps each equipped with a LED module lighting system having a plurality of LED modules controlled by a thermally responsive controller of a LED lighting control system that senses or measures a temperature of each luminaire or lamp to control operation of the LED modules of each luminaire or lamp in a manner that maintains minimum light output while also providing LED module thermal protection. In one high output lighting system 
     The LED module lighting system has a plurality of LED modules carried by a luminaire or lamp. Each of the multiple LED modules has a plurality of LEDs arranged to project light out of the lamp. In a preferred embodiment, each of the multiple LED modules has at least a plurality of pairs, i.e., at least three, rows of LEDs with each row of LEDs having at least a plurality of pairs of LEDs. The LED module lighting system defines a heat detection zone at which heat is detected to define a detected temperature inside of the lamp. A control system is connected to the LED module lighting system for controlling an amount of electrical power delivered to at least one of the multiple LED modules to regulate temperature of the LED module lighting system based at least in part on the detected temperature inside of the lamp. Such a control system preferably enables operation of the multiple LED modules of the LED module lighting system to be controlled or regulated in order to optimize light output under high temperature operating conditions. 
     The heat detection zone may be defined upon at least one of the multiple LED modules. The heat detection zone may be defined within a heated zone of the at least one of the multiple LED modules receiving heat energy from the LEDs of the respective at least one of the multiple LED modules. A temperature sensor may be mounted at the heat detection zone of the at least one of the multiple LED modules. The temperature sensor may be defined by a thermocouple mounted to the at least one of the multiple LED modules. A first one of the multiple LED modules may be controlled based on the detected temperature inside of the lamp and a second one of the multiple LED modules is not controlled based on the detected temperature inside of the lamp. The multiple LED modules may define a pair of unregulated LED modules that are not controlled based on the detected temperature inside of the lamp. The control system may modulate at least one regulated LED module by controlling the amount of electrical power delivered to the at least one regulated LED module, and the at least one regulated LED module may be arranged between the pair of unregulated LED modules. The at least one regulated LED module may be defined by a pair of regulated LED modules that is arranged between the pair of unregulated LED modules. This may allow for a relatively compact configuration of a temperature controlled high output LED lighting system. 
     A heatsink may be mounted to and extend outwardly with respect to the lamp and be connected to the multiple LED modules for dissipating heat from the LED system. The heat detection zone may be defined within a heated zone of at least one of the multiple LED modules receiving heat energy from the LEDs of at least one of the multiple LED modules such that the detected temperature inside of the lamp corresponds to a detected temperature of the first LED module. The heatsink may include a wall defining upper and lower portions. Heated zones of adjacent LED modules may be on opposing ones of the upper and lower portions of the wall of the heatsink. Each of the LED modules may include a connector coupling the respective LED module to conductors extending to the control system. The connectors of adjacent LED modules may be on opposing ones of the upper and lower portions of the wall of the heatsink. The heatsink may have a front wall and the lamp may define a reflector with a reflector back wall. The heatsink front wall and the reflector back wall may engage so as to transmit heat between each other. The reflector back wall may include an opening and the multiple LED modules may be arranged within the opening of the reflective back wall. This may allow for a high output LED lighting system that can efficiently dissipate system heat. 
     A method of providing high intensity lighting with a lighting system to a location to be illuminated may include delivering electrical power to a first LED module mounted in a lamp to illuminate the first LED module. Electrical power is delivered to a second LED module mounted in the lamp to illuminate the second LED module. A temperature inside of the lamp is detected. An amount of electrical power delivered may be reduced more to one of the first and second LED modules than the other one of the first and second LED modules based at least in part on the detected temperature inside of the lamp to reduce the temperature inside of the lamp. This may provide a method of providing high intensity lighting to ensure that a minimum acceptable lighting value is provided at all times while thermally protecting the LED system. 
     The high output lighting system may include LED modules that can be used with a light tower. The lamp may allow for long durations of high output from the LED modules by way of a temperature management system. The temperature management system allows some of the LED modules to remain energized and emit light at all times during use and control other LED modules based on detected temperature(s). This may ensure that a minimum acceptable lighting value is provided at all times by the high output lamp when the light tower is activated while thermally protecting the LED modules. 
     The lamp may include a light fixture with a casing having a reflector defining a reflector opening from which light is directed from the reflector toward a location to be illuminated. A heatsink may extend from the reflector and have a wall facing toward the reflector opening. Multiple LED modules may be supported by a wall of a heatsink. Each of the LED modules may include LEDs arranged to project light out of the light fixture opening and a chip operably connected to the LEDs such as a separate chip upon which each LED is mounted for delivering electrical power to the LEDs. Each chip may define a location of direct heat transfer to a board or substrate of the respective LED module, whereby a heated zone is defined peripherally about and across a collective matrix of LED chips at each LED module, defining a zone at which heat is concentrated for the respective LED module. The chips of the LED modules may be arranged with respect to each other so that the heated zones are spaced from each other relative to the wall of the heatsink. The lamp may define a light of a light tower, such as a portable light tower. This may allow for distributing localized concentrations of high heat transmission from the LED modules to the heatsink across a relatively large surface area of the heatsink. This may allow for efficient cooling of LED modules in a light tower having LED-based lights. 
     A first one of the multiple LED modules may be controlled based on a temperature within the lamp and a second one of the multiple LED modules may not be controlled based on the temperature within the lamp. The control of the first one of the multiple LED modules may be done based on the temperature of the first one of the multiple LED modules itself. 
     The multiple LED modules may define a pair of unregulated LED modules that are not controlled based on a temperature of the respective LED modules and at least one regulated LED module that is controlled based on a temperature of the respective at least one LED module. The at least one regulated LED module may be arranged between the pair of unregulated LED modules. The multiple LED modules may define a pair of regulated LED modules that are controlled based on a temperature of the pair of regulated LED modules. The pair of regulated LED modules may be arranged between the pair of unregulated LED modules or the regulated and unregulated LED modules may be arranged in an alternating sequence with respect to each other. Controlling fewer than all of the LED modules may allow for running fewer wires from the LED modules to a power source that would otherwise be required if all of the LED modules were regulated. 
     Temperature of the LED modules may be controlled while ensuring that the lamp emits a sufficient amount of light by including at least one regulated LED module and at least one unregulated LED module arranged within a reflector of a light tower for directing light to a location to be illuminated. Electrical power may be delivered to the at least one regulated LED so as to illuminate the at least one regulated LED. Electrical power may be delivered to the at least one unregulated LED module so as to illuminate the at least one unregulated LED module. A temperature within the lamp may be detected. An amount of electrical power delivered to the regulated LED module(s) may be reduced based at least in part on the detected temperature while maintaining an amount of electrical power delivered to the unregulated LED module(s). The reduction may be an on/off type modulation or a throttling-type or dimming-type reduction in the amount of electrical power delivered to the regulated LED module(s). 
     The wall of the heatsink may define upper and lower portions, and heated zones of adjacent LED modules may be on opposing ones of the upper and lower portions of the wall of the heatsink. The wall of the heatsink may define a heatsink front wall and the reflector may include a reflector back wall. The heatsink front wall and the reflector back wall may engage so as to transmit heat between each other. The reflector back wall may include an opening in which the multiple LED modules are arranged. This may allow for a compact configuration with efficient heat transfer between the heatsink and other components of the lamp. 
     The heatsink may cover the back wall opening of the reflector and be secured to the reflector by multiple fasteners that are spaced from each other and are arranged outwardly of the back wall opening of the reflector. A gasket may be arranged to provide a watertight seal between the heatsink and the reflector. The gasket may be arranged outwardly of the back wall opening on the reflector and the multiple fasteners. A backing plate may be arranged toward the reflector opening so that the reflector back wall is sandwiched between the backing plate and the heatsink. This may allow for a liquid tight seal and a relatively large amount of face-to-face surface area between a plate and reflector. Providing a gasket outboard of the mounting bolts may help maintain seal at the bolts, allowing for use of a gasket with a relatively small cross-sectional area. This may allow for a high clamping force and deflection of the gasket and may relatively reduce a thermal barrier between a clamping engagement defined between the heatsink and the reflector and relatively increase a surface area of the engaging surfaces of the heatsink and reflector. This may allow for a thermal transfer relationship between the heatsink and the reflector which may allow the reflector to perform supplemental heat dissipation. 
     A pair of mounts may be arranged on opposing sides of the reflector toward the reflector back wall with a pivot axis of the lamp defined through an intermediate portion of the pair of mounts. Each of the mounts may define front and back edges and the pivot axis of the lamp may extend closer to the back edges than the front edges of the mounts. This may allow for the center of gravity of the lamp to be aligned with the pivot axis of the lamp so as to minimize forces required to resist offset center of gravity torque components which may otherwise occur with a heatsink extending rearwardly from the lamp. 
     In one preferred method of operating a high intensity lighting system having at least one lamp with a plurality of light emitting LED modules to maintain a desired minimum light output level from the lamp under high temperature operating conditions, electrical power is delivered to the LED modules causing light to be outputted from the lamp, a temperature of the lamp is detected, and the delivery of the electrical power to the LED modules is controlled when the detected lamp temperature exceeds a threshold temperature that provides enough electrical power to maintain a light output level at or above the minimum light output level while enabling cooling to occur that reduces the detected temperature to below the threshold temperature. In one such preferred control method, electrical power delivered to at least one of the LED modules is reduced while the detected temperature is monitored while electrical power delivered to at least one other LED module is not reduced enabling cooling of one or more LED modules of the lamp to occur while causing the lamp to output a desired minimum light output level while this is being done. If desired, delivery of electrical power to at least one of the LED modules of a lamp can be done while delivery of electrical power is maintained to at least one of the other LED modules of the lamp can be done when controlling electrical power delivery when a lamp temperature greater than the threshold temperature is detected. 
     When electrical power is delivered at the same time to each one of the plurality of LED modules of a lamp, such as during lamp startup and when the detected temperature is below the threshold temperature, light is outputted at the same time from all of the LED modules of the lamp causing the lamp to output light at a first lumen output level that is greater than the minimum light output level, i.e., minimum lumen output level. When the same amount or magnitude of electrical power is delivered to each one of the plurality of LED modules of a lamp at the same time, such as during lamp startup and when the detected temperature is below the threshold temperature, a maximum lumen output level of light is outputted from each LED module of the lamp at the same time causing the lamp to output light at a maximum lumen output level that is greater than the minimum light output level, i.e., minimum lumen output level. 
     A controller preferably is used to monitor lamp temperature preferably by detecting a temperature of the lamp within a zone of or onboard the lamp that encompasses at least one of the LED modules of the lamp and which can encompass a plurality of the LED modules of the lamp. Where one or more of the LED modules of the lamp are equipped with an onboard temperature sensor, e.g., thermocouple, temperature detection can be accomplished by the controller monitoring the temperature of at least one of the LED modules by detecting the temperature of the onboard temperature sensor of at least one of the LED modules. In one preferred embodiment, a temperature sensor. e.g., thermocouple, used to detect lamp temperature can be mounted to part of the lamp adjacent to one or more of the LED modules. Where mounted to part of the lamp, such a temperature sensor can be mounted to a housing or fixture of the lamp close enough to at least one of the LED modules of the lamp to enable detected lamp temperature to be indicative of the temperature of at least one of the adjacent LED modules. Such a temperature sensor preferably is located close enough to at least one of the LED modules of the lamp and preferably is located close enough to all of the LED modules of the lamp so that the temperature sensor is used to detect the temperature of the lamp in a heat detection zone encompassing at least one of the LED modules of the lamp that preferably encompasses all of the LED modules of the lamp or a heat detection zone within a heated zone encompassing at least one of the LED modules of the lamp that preferably encompasses all of the LED modules of the lamp. 
    
    
     
       DRAWING DESCRIPTION 
       Preferred exemplary embodiments of the invention are illustrated in the accompanying drawings in which like reference numerals represent like parts throughout, and in which: 
         FIG. 1  is a simplified schematic front elevation view of a temperature controlled high output lighting system constructed in accordance with the present invention; 
         FIG. 2  is a perspective view of a portable light tower equipped with a lighting system constructed in accordance with the present invention; 
         FIG. 3  is a perspective view of the portable light tower of  FIG. 1  shown in a first storage or transport position; 
         FIG. 4  is a close-up perspective view of a lighting system of the portable light tower of  FIG. 2 ; 
         FIG. 5  is a perspective exploded view of a lighting system in accordance with the present invention; 
         FIG. 6  is a perspective exploded view of a variant of the lighting system of  FIG. 5 ; 
         FIG. 7  is a partially schematic simplified front elevation view of a lighting system in accordance with the present invention; 
         FIG. 8  is a partially schematic simplified front elevation view of a variant of the lighting system of  FIG. 7 ; 
         FIG. 9  is a partially schematic simplified front elevation view of another variant of the lighting system of  FIG. 7 ; 
         FIG. 10  is a partially schematic simplified front elevation view of a variant of the lighting system of  FIG. 9 ; and 
         FIG. 11  is a diagram depicting a method of using a lighting system in accordance with the present invention. 
     
    
    
     Before explaining one or more embodiments of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments, which can be practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting. 
     DETAILED DESCRIPTION 
       FIG. 1  illustrates a simplified schematic representation of a thermally responsive LED lighting control system  5  for use with indoor and/or outdoor lighting systems and applications having an LED lighting system  7  and a temperature responsive lighting power control system  9 . Control system  9  is operably connected to and controls the LED lighting system  7  based on temperature to ensure that a minimum acceptable lighting output value is provided at all times while thermally protecting the LED lighting system  7 , as explained in greater detail elsewhere herein. The LED lighting control system  5  includes a luminaire or lamp  11 , only a portion of which is shown in  FIG. 1 , in which the LED lighting system  7  is mounted. The LED lighting system  7  includes multiple LED modules  13  mounted inside of the luminaire  11 . Each of the LED modules  13  has an electrical connector  10  and electrical conductors  10   a  extending from and electrically connecting the control system  9  to a matrix or array of LED chip assemblies  15  mounted to a substrate or board  13   a  of each corresponding LED module  13 . Each of the LED chip assemblies  15  includes an LED chip  15   a  which is mounted to the board  13   a  and an LED  15   b  mounted to the LED chip  15   a  that emits light when electrically powered. 
     In at least one preferred embodiment, each LED module  13  of LED lighting system  7  has a plurality of pairs, i.e., at least three, of rows with each one of the rows having a plurality of pairs, i.e., of LEDs  15   b . In such a preferred embodiment, each one of the LEDs  15   b  can be part of an LED chip assembly  15  formed of a chip  15   a  that carries LED  15   b.    
     Still referring to  FIG. 1 , a heat detection zone  17  is defined within the luminaire  11  from which a temperature inside of the luminaire  11  is detected and used by the control system  9  to regulate power to at least one of the LED modules  13  to thermally regulate one or more of the LED modules  13 . Based on the detected temperature inside of the luminaire  11 , the control system  9  regulates the amount of electrical power delivered to at least one of the LED modules  13  in controlling the temperature of the LED system  7  to thermally protect the LED modules  13 . Based on the detected temperature inside of the luminaire  11 , the control system  9  controllably reduces the amount of electrical power delivered to at least one of the LED modules  13  to reduce the temperature of the LED system  7  if the detected temperature becomes too high. 
     In a preferred method of controlling temperature, the control system  9  regulates the amount of electrical power delivered to at least one of the LED modules  13  of the luminaire  11  by attenuating the voltage of the delivered electrical power in response to detected temperature. In another preferred method of controlling temperature, the control system  9  regulates the amount of electrical power delivered to at least one of the LED modules  13  of the luminaire  11  by attenuating the current of the delivered electrical power in response to detected temperature. If desired, the control system  9  can selectively vary or control the amount of electrical power delivered to at least one of the LED modules  13  of the luminaire  11  using pulse width modulation (PWM) to maintain a desired minimum light output while thermally regulating one or more of the LED modules  13 . 
     The control system  9  can be or include a regulated power supply capable of receiving and regulating electrical power from a power source at one voltage and/or amperage to deliver the electrical power to at least one of the LED modules  13  of the luminaire  11  at another voltage and/or current. If desired, the control system  9  can be electrically connected to a separate regulated power supply (not shown) capable of receiving and regulating electrical power from a power source at one voltage and/or amperage to deliver the electrical power to at least one of the LED modules  13  of the luminaire  11  at another voltage and/or current. As discussed in more detail below, the power source from which electrical power is ultimately supplied can be in the form of utility electrical power, e.g., 110-125 volts AC, one or more batteries, e.g., 6 volt and/or 12 volt lead-acid and/or gel batteries, an electrical generator that supplies electrical power at voltages ranging from about 12 volts to 125 volts AC, one or more solar cells, or the like. 
     In the embodiment shown in  FIG. 1 , the heat detection zone(s)  17  is defined at a location in the luminaire  11  where at least one of the LED modules  13  and a temperature sensor  18  is disposed. The temperature sensor  18  can be a thermocouple or another type of sensor from which a temperature can be sensed or measured that is located within the heat detection zone(s) in close enough proximity to at least one adjacent LED module  13  that the detected temperature provided by the sensor  18  is indicative or representative of an LED module operating temperature of the at least one adjacent LED module  13 . While the temperature sensor  18  can be mounted directly to the luminaire  11  or located between the at least one adjacent LED module  13  and the luminaire  11 , the temperature sensor  18  preferably is disposed onboard the at least one adjacent LED module  13 . 
     Where the temperature sensor  18  is disposed onboard an adjacent LED module  13 , the temperature sensor  18  can be a thermocouple or other type of temperature sensor located within a heat detection zone  17  located close enough to a heated zone  19  of the adjacent LED module  13  that heats up to a temperature of at least ten degrees Fahrenheit above the ambient temperature of air outside the luminaire  11  when electrical power is supplied to the LED module  13 . 
     As is also shown in  FIG. 1 , the heated zone  19  of the LED module  13  is defined by an area corresponding to a portion of the board  13   a  of the LED module  13  that increases in temperature more than other portions of the LED module  13  when electrical power is delivered to the module  13  at a sufficient voltage and amperage to cause the module  13  to emit light. With continued reference to  FIG. 1 , the heated zone  19  is shown as a dashed line that bounds or encircles the outer periphery of the matrix or array of LED chip assemblies  15  of the LED module  13 . The heated zone  19  is defined peripherally about and extends across the collective matrix or array of all of the LED chip assemblies  15  of the LED module  13 . 
     In one preferred embodiment, the heated zone  19  is an area of the LED module  13  that extends peripherally around all of the LEDs  15   b  of the LED module  13  and encompasses the portion of the LED module  13 , namely the board  13   a  of the LED module  13 , that heats up to a heats up to a temperature of at least five degrees Fahrenheit greater than the ambient temperature of air outside the luminaire  11  when electrical power is supplied to the LED module  13 . In another preferred embodiment, the heated zone  19  is an area of the LED module  13  that extends peripherally around all of the LEDs  15   b  of the LED module  13  and encompasses that portion of the LED module  13 , namely the board  13   a  of the LED module  13 , that heats up to a heats up to a temperature of at least ten degrees Fahrenheit above the ambient temperature of air outside the luminaire  11  when electrical power is supplied to the LED module  13 . 
     As is shown in  FIG. 1 , the shape of the heated zone  19  substantially conforms to that of the shape, e.g., outer peripheral shape, of the matrix or array of the LEDs  15   b  of the LED module  13 . As such, the generally rectangular shape of each one of the heated zones  19  shown in  FIG. 1  substantially conforms to or is substantially the same as the generally rectangular shape of the matrix or array of LEDs  15   b  of the corresponding module  13 . 
     While the heat detection zone  17  of an LED module  13  can be located outside of the heated zone  19  of the module  13 , the heat detection zone  17  is in thermally conductive communication with the heated zone  19  so that a temperature detected at such remote heat detection zone  17  correlates to a temperature of the heated zone  19  of the LED module  13  and preferably correlates to a detected temperature of the temperature sensor  18 . Regardless of where the heat detection zone  17  and/or temperature sensor  18  is located within the luminaire  11 , the control system  9  is configured to vary or modulate electrical power delivered to at least one of the LED modules  13  based on a detected temperature in the heat detection zone  17  in a manner that reduces the amount of electrical power delivered in order to reduce the temperature of at least one of the LED modules  13 . The control system  9  is configured to do so while still supplying enough electrical power to at least one of the other LED modules  13  to substantially continuously maintain a minimum acceptable lumen or lux light output emitted from the luminaire  11 . By throttling down the amount of electrical power supplied to at least one of the LED modules  13  in response to detected temperature while still supplying enough electrical power to at least one of the other LED modules  13  to maintain the desired minimum acceptable lumen or lux light output from the luminaire  11 , effective operation of the luminaire  11  is maintained while thermally protecting the LED modules  13  by preventing them from overheating. 
     In a preferred embodiment and method of controlling a luminaire  11  having at least a plurality of LED modules  13 , electrical power supplied to at least one of the LED modules  13  is throttled down or otherwise attenuated in proportion to the amount the detected temperature exceeds a predetermined threshold temperature thereby providing an opportunity to cool or reduce the operating temperature of at least one of the LED modules  13  of the luminaire  11 . Once the detected temperature drops below the threshold temperature after cooling takes place, throttling or attenuation of electrical power delivered to each and every one of the LED modules  13  of the luminaire  11  ceases causing the luminaire  11  to resume full lumen or lux light output. 
       FIGS. 2 and 3  illustrate the thermally responsive LED lighting control system  5  incorporated into an exemplary but preferred high output lighting system in the form of an outdoor portable light tower  20 . Light tower  20  is equipped with at least one and, typically, a plurality of luminaires  11  shown in  FIGS. 2 and 3  as spaced apart outdoor tower lights  22  arranged in a bank or array  24  of lights  22  having a plurality of rows of lights  22  with each row of lights  22  having a plurality of lights  22 . Each luminaire  11  or light  22  shown in  FIGS. 2 and 3  includes a light fixture  26  with a substantially transparent lens  28  removably attached to a casing  29  having a reflector  30  providing a substantially weather tight enclosure in which a source of light, namely LED lighting system  7 , is disposed. The light fixture casing  29  preferably is made of aluminum or an aluminum to produce a strong, weather resistant, corrosion resistant and lightweight luminaire  11  or light  22  that relatively efficiently conducts heat away from the LED modules  13  of the LED lighting system  7  during lighting system operation and helps dissipate the heat to the ambient air outside of the light fixture  26  that surrounds the fixture  26 . In a preferred embodiment, the casing  29  and/or reflector  30  is cast of aluminum or an aluminum alloy. The lens  28  can be made of glass, such as tempered glass, but preferably is made of a plastic, preferably polycarbonate, but can be made of another suitable type of plastic. 
     The light tower  20  includes an upright mast  36  that can be of telescoping construction, such as is depicted in  FIGS. 2 and 3 . As is shown in  FIG. 2 , the mast  36  extends uprightly from a mount  38  that can be part of a base  40  attached to a wheeled trailer or other transport vehicle  42 , such as a trailer/transport vehicle  42  equipped with a source of electrical power. Such a source of electrical power can be in the form of electrical charge storage devices, such as one or more batteries or the like, can be in the form of a generator, such as an internal combustion engine powered generator, or can be configured in another manner, such as with solar cells or the like, to provide electrical power to charge the batteries, and ultimately supply electrical power to each luminaire  11  or light  22 . 
     A mount  38  and/or base  40  can pivotally support the mast  36  of the tower  20  in a manner that allows the tower  20  to be movable between a generally upright orientation, such as the upright operating position shown in  FIG. 2 , and a transport or storage orientation, such as the generally horizontal storage/transport position shown in  FIG. 3 . To provide increased stability when the mast  36  of the tower  20  is disposed in its upright operating position, one or more removable outriggers  44  can be extended from the base  40  or another portion of the vehicle  42 . Tongue  46  is also configurable, such as in the manner depicted in  FIG. 2 , to further help increase stability. As is shown in  FIG. 3 , mast  36  can be received in a cradle  45  spaced from a pivot  47  of mount  38  when disposed in the generally horizontal storage position with the cradle  45  carried by part of vehicle  42 , such as a housing  49  that encloses the onboard source of electrical power. A bracket  48  attaches the luminaires  11  or lights  22  to a crossbar  50  of a carriage  52  disposed at or adjacent the upper or free end of the mast  36  of the tower  20 . Bracket  48  can be constructed and arranged to pivotally attach to opposite sides of the fixture  26  or casing  29  of each luminaire  11  or light  22  in a manner that can permit the angle of the luminaire  11  or light  22  to be adjusted, as well as to allow pivoting of each luminaire  11  or light  22  to a storage position. 
     Referring now to  FIG. 4 , in this embodiment, the luminaire  11  or light  22  includes a light fixture casing  29  that defines a generally oval shape that can include or integrally form or provide a reflector  30  that can also be generally oval in shape. A pair of light fixture mounts  54  extend outwardly from opposite sides  56 ,  58  of the casing  29 . Each mount  54  is shown arranged toward a casing back wall  60  and is shown as an ear mount with back and front edges  62 ,  64  defined at back and front portions  66 ,  68 , respectively. The back portion  66  tapers toward the front portion  68  so that the back and front portions  66 ,  68  provide a generally flat face  70  with a triangular perimeter shape. A stud  72  extends from each of the mounts  54  to connect the light  22  to a corresponding arm  74  of the bracket  48 . A pivot axis  76 , about which the light  22  can pivot, is defined through the studs  72 . The studs and pivot axis  72 ,  76  are arranged at intermediate portions of the mount  54  and may be closer to the back edges  62  than the front edges  64  for minimizing forces required to resist offset center of gravity torque components. Pivoting the lights  22  about the pivot axes  76  allows for directing light emitted from the luminaire  11  or light  22  toward a desired area to be illuminated. 
     The emitted light is produced by a light source that preferably is in the form of an LED lighting system  7 , shown in  FIG. 4  as having two LED modules  13  mounted to part of the casing  29  within the light fixture  26  and covered by lens  28 . The LED lighting system  7  can be in the form of a module, board or the like that carries the LED modules  13  with the LED lighting system  7  substantially weather tightly sealed by the lens  28  within the casing  29  such that the LED lighting system  7  is housed within the light fixture  26 . 
     Referring now to  FIGS. 5 and 6 , gaskets  82  are arranged for providing a substantially weather tight and/or water tight seal between the mounts  54  and the light fixture casing  29 . Where the reflector  30  is integrally formed of or with the casing  29  such as is shown in  FIGS. 5 and 6 , the gaskets  82  can be arranged for providing a substantially weather tight and/or water tight seal between the mounts  54  and the reflector  30 . Toward an opening  84  at a forward facing end  31 a of the reflector  30  from which light beams are emitted from the light  22  during operation, the lens  28  is sealed against the casing  29  by way of a rubber ring as a gasket  86  is compressed against an outer perimeter of the lens  28  with a ring clamp  88 . A rearward facing end  31 b of the reflector  30  includes a reflector back wall  90  that defines a recessed shelf  92  with an opening  94  defined inwardly of an inner perimeter  96 . 
     The luminaire  11  or light  22  preferably also includes a heatsink  98  that conducts heat away from each one of the LED modules  13  of an LED lighting system  7  received within the light fixture casing  29 . The LED lighting system  7  is in contact with the heatsink  98  causing heat generated by the LED modules  13  of the LED lighting system  7  during operation to be transferred via thermal conduction away from the LED lighting system  7  where the heat is dissipated to the ambient air outside of the luminaire  11  or light  22 . The LED lighting system  7  preferably is mounted to the heatsink  98  such that the LED lighting system  7  is in direct contact with the heatsink  98  conducting heat generated by the LED modules  13  of the LED lighting system  7  to ambient. A thermally conductive paste, such as ARTIC SILVER or the like, can be disposed between the LED lighting system  7  and the heatsink  98 . If desired, each one of the LED modules  13  of the LED lighting system  7  can be in direct contact with the heatsink  98 , can have thermally conductive paste between each LED module  13  and the heatsink  98 , and can be fixed directly to the heatsink  98  if desired. The heatsink  98  has a plurality of pairs of spaced apart and outwardly extending heat transfer fins  111  that extend outwardly into the ambient air exteriorly surrounding the fixture  26  of the luminaire  11  or light  22 . 
     The LED lighting system  7  can be pre-assembled to the heatsink  98  by being fixed to the heatsink  98  forming a pre-assembled module that can be plugged into an opening in the light fixture casing  29  during assembly of the luminaire  11  or light  22 . The heatsink  98  is formed, e.g., cast, of a metal that preferably is aluminum or an aluminum alloy helping to more efficiently conduct and dissipate heat produced by the LED modules  13  of LED lighting system  7  when emitting light during luminaire or light operation. 
     A wall of the heatsink  98 , shown as a front wall  100 , covers the back wall opening  94  of the casing  29  and/or reflector  30 . Fins  111  of the heatsink  98  extend in an opposite direction relative to the front wall  100 , extending outwardly with respect to the reflector back wall  90 . The heatsink front wall  100  faces toward the opening  84  of the reflector  30  and an outwardly facing surface of the reflector back wall  90 . A backing plate  102  is arranged within the opening  94  and sits within a recess  104  of the recessed shelf  92 . The backing plate  102  defines outer and inner perimeters  106 ,  108  that are generally rectangular in shape. An opening  110  is defined within the inner perimeter  108  of the backing plate  102 . The opening  110  is aligned with the opening  94  of the reflector back wall  90 . Multiple fasteners  112  are spaced from each other and are arranged outwardly of the back wall and backing plate openings  94 ,  110 . The fasteners  112  extend through bores  114 ,  116  of the backing plate  102  and reflector back wall  90  and are threadably received in bores  118  of the heatsink front wall  100 , so that the reflector back wall  90  is sandwiched between the backing plate  102  and the heatsink  98 . A gasket  120  provides a seal between the back wall  90  and the heatsink  98  to establish a watertight seal toward the rearward facing end  31 b of the reflector  30 . The gasket  120  is arranged outwardly of the back wall and backing plate openings  94 ,  110  and the fasteners  112 . The heatsink front wall  100  may include a groove  122  that receives the gasket  120  for locating the gasket  120  in an outboard or outwardly disposed position with respect to the fasteners  112 . Water drain valves (not shown) may be arranged at the light  22  to allow water to drain out of the reflector  30 . 
     Still referring to  FIGS. 5 and 6 , a platform  124  extends from a middle portion  126  of the heat sink front wall  100  and has an outer perimeter  128  that corresponds to the inner perimeter  96  of the reflector back wall  90  to allow the platform  124  to nest within the inner perimeter  96 . The outer perimeter  128  of platform  124  may engage the inner perimeter  96  of the reflector back wall  90  and/or inner perimeter  108  of the backing plate  102  to allow thermal transfer between the heatsink  98  and the reflector  30 , in addition to respective interfacing surfaces of the heatsink front wall  100  and the reflector back wall  90 . This can and preferably does help facilitate dissipation of heat from the LED modules  13  that are secured to the platform  124  by fasteners  130 .  FIG. 5  shows an embodiment in which two LED modules  13  are secured to the platform  124  and  FIG. 6  shows an embodiment in which four LED modules  13  are secured to the platform  124 , although it is understood that other numbers of LED modules may be provided within the LED system  7 . Regardless of how many LED modules  13  are provided within the LED system  7 , each of the LED modules  13  receives power from a respective power source of the control system  9 , shown as an LED driver  132  by way of conductors  10   a . Each of the conductors  10   a  may include multiple wires or other conductors for transmitting electrical power and signals. The LED driver(s)  132  may be arranged at a location that is remote from the reflector  30 , shown in the embodiments as arranged within the housing  49 , although it is understood that the LED driver(s)  132  may be arranged at another location within the light tower  20 . 
     Referring now to  FIGS. 7-10 , the thermally responsive LED lighting control system  5  has a temperature control system  136  that includes a heatsink  98  that removes heat from the LED modules  13  during lighting system operation and a temperature controlling arrangement  138  that is defined at least in part by the temperature responsive lighting power control system  9 . In one embodiment, the temperature controlling arrangement  138  cooperates with a controller  140  of the control system  9  to provide power to or otherwise control at least one LED driver  132  and the corresponding LED modules  13 . The controller  140  may include a processor, e.g. microcontroller, an industrial computer or, e.g., a programmable logic controller (PLC), along with corresponding software, firmware, and/or suitable onboard memory and/or data storage for storing such software, firmware, detected temperature data and the like including interconnecting conductors for power and signal transmission to the LED driver(s)  132  for maintaining the temperature of the LED modules  13  below a maximum allowable temperature, as explained in greater detail elsewhere herein. 
     Still referring to  FIGS. 7-10 , each of the LED modules  13  includes multiple LED chip assemblies  15  arranged to project light out of the light fixture opening  84  and a connector  10  and conductors  10   a  electrically connecting the LED chip assemblies  15  to the LED driver(s)  132  of the control system  9 . The heat detection zones  17  are provided at locations for measuring temperature of the LED modules  13  by way of a temperature sensor  18 , such as at the heat detection zones  17  defined within heated zones  19  upon the LED modules  13  and/or interface of the LED modules  13  and wall  100  of heatsink  98 . In another embodiment, the detection zones  17  are provided at locations for indirectly measuring temperature of the LED modules  13 . In such embodiments configured for indirectly measuring temperature, the detection zones  17  are spaced from the LED modules  13 , but within a path of thermal conductivity with the heated zone  19 , for example, upon the wall  100  of this heatsink  98 , but spaced from the LED modules  13 . The heated zones  19  of the LED modules  13  are defined at the heatsink  98  at locations that correspond to the respective matrices of LED chip assemblies  15  of the LED modules  13 . The heated zones  19  define localized areas of relatively high heat transmission from the LED modules  13  to the heatsink  98 . The LED modules  13  are arranged with respect to each other upon the heatsink  98  so that the heated zones  19  are spaced from each other, shown as adjacent heated zones  19  being in an alternating relationship relative to upper and lower portions  148 ,  150  of the wall  100  of the heatsink  98 . 
     Still referring to  FIGS. 7-10 , in at least one embodiment, the temperature control system  136  is configured to ensure that a minimum acceptable lumen or lux lighting output value is provided at all times by the LED system  7  while controlling electrical power supplied to at least one of the LED modules  13  to thermally protect the LED modules  13 . The temperature control system  136  preferably is configured to reduce the amount of electrical power supplied to at least one of the LED modules  13  of the LED lighting system  7  of the luminaire  11  or light  22  when a temperature in a detection zone  17  exceeds a preset threshold temperature by attenuating the voltage and/or current of the electrical power supplied to at least one of the LED modules  13 . Attenuation of the electrical power supplied to at least one of the LED modules  13  of the LED lighting system  7  can be and preferably is increased proportional to the number of degrees the detection temperature is over or greater than the predetermined threshold temperature. In one temperature control system control method, the voltage and/or current of the electrical power supplied to at least one of the LED modules  13  of the LED system  7  is attenuated by decreasing the magnitude of the voltage and/or current linearly as the detected temperature exceeds the threshold temperature. In another temperature control system control method, the voltage and/or current of the electrical power supplied to at least one of the LED modules  13  of the LED system  7  is attenuated by decreasing the magnitude of the voltage and/or current stepwise either linearly or in proportion relative to the amount that the detected temperature exceeds the threshold temperature. 
     As discussed in more detail below, in at least one of the aforementioned control methods the temperature control system  136  is configured to carry out, the LED system  7  has at least a plurality of LED modules  13  arranged side-by-side adjacent one another with at least one of the LED modules  13  being a regulated module that is regulated by attenuating electrical power supplied thereto when the detected temperature exceeds a predetermined threshold temperature with at least one of the other LED modules  13  being unregulated such that electrical power supplied thereto is not regulated such that the electrical power supplied to each unregulated LED module  13  remains substantially constant. In at least one of the aforementioned control methods that the temperature control system  136  is configured to carry out, the LED system  7  has at least a plurality of pairs, i.e., at least three, LED modules  13  arranged side-by-side adjacent one another with at least one of the LED modules  13  being a regulated LED module that is regulated by attenuating electrical power supplied thereto when the detected temperature exceeds a predetermined threshold temperature with at least a plurality of the other LED modules  13  being unregulated LED modules such that electrical power supplied thereto is not regulated such that the electrical power supplied to each unregulated LED module  13  remains substantially constant. 
     In at least one such control method that the temperature control system  136  is configured to carry out, the LED system  7  has at least a plurality of pairs, i.e., at least three, LED modules  13  arranged side-by-side adjacent one another with at least one of the LED modules  13  disposed in between a pair of the LED modules  13  being a regulated module and the LED module  13  on either side of the regulated module being an unregulated module. In one such control method that the temperature control system  136  is configured to carry out, the LED system  7  has three LED modules  13  arranged side-by-side adjacent one another in the manner shown in  FIG. 8  with the outer LED modules  13  being unregulated modules and the inner LED module  13  disposed between the outer LED modules being a regulated module. 
     In at least one other such control method that the temperature control system  136  is configured to carry out, the LED system  7  has four LED modules  13  arranged side-by-side adjacent one another such as in the manner shown in  FIGS. 9  and/or  10  with at least one of the inner LED modules  13  disposed in between a pair of the LED modules being a regulated module and the LED module on either side of the inner regulated module being an unregulated module. In one such LED lighting system  7  equipped with four LED modules  13  arranged side-by-side adjacent one another in the manner shown in  FIG. 9  and/or  FIG. 10  has a pair of outer LED modules  13  between which is disposed a pair of inner LED modules  13  with the inner LED modules  13  being regulated LED modules and the outer LED modules being unregulated LED modules. In another such LED lighting system  7  equipped with four LED modules  13  arranged side-by-side adjacent one another in the manner shown in  FIG. 9  and/or  FIG. 10  has alternating regulated and unregulated LED modules such that one of the first and third LED modules  13  and the second and fourth LED modules  13  are regulated LED modules and the other one of the first and third LED modules  13  and the second and fourth LED modules  13  are unregulated LED modules. 
     Referring now to  FIG. 7 , in this embodiment, the LED system  7  includes two LED modules  13 . A minimum lighting value such as a minimum acceptable lighting value can be provided by a single one of LED modules  13 , represented as an unregulated LED module  80   a.  During use of the thermally responsive LED lighting control system  5 , the unregulated LED module  80   a  may receive electrical power from an unregulated LED driver  132   a  of the control system  9  for constantly illuminating the unregulated LED module  80   a . Heat is constantly produced in the heated zone  19  of the unregulated LED module  80   a  and is constantly drawn into the heatsink  98  at the heated zone  19  and dissipated through the heatsink  98  for thermal transfer to the surrounding air and cooling of the LED modules  13 . A regulated LED module  80   b  may receive electrical power from a regulated LED driver  132   b  of the control system  9  for variably illuminating the regulated LED module  80   b  based on a detected temperature. The temperature sensor  18  may be arranged at the regulated LED module  80   b  and operably connected to the temperature control system  136  for detecting a temperature that is evaluated by the temperature control system  136  for regulating the regulated LED module  80   b . The temperature sensor  18  may be arranged at a different location on the regulated LED module  80   b  or other location(s), such as at the unregulated LED module  80   a , on the heatsink  98 , reflector  30 , or other location within the light  22 . The unregulated and regulated LED modules  80   a ,  80   b  are shown spaced from each other by a distance that is at least as wide as the LED modules  13 , with the unregulated module  80   a  arranged toward a first or left side  154  of the heatsink  98  and the regulated module  80   b  arranged toward a second or right side  156  and within an intermediate portion  158  of the heatsink  98 . In one embodiment, the unregulated module  80   a  is arranged within the intermediate portion  158  and the regulated module  80   b  is arranged toward the first or second side  154 ,  156  of the heatsink  98 . The unregulated and regulated LED modules  80   a ,  80   b  may be arranged both within the intermediate portion  158  of the heatsink  98 , or both outside of the intermediate portion  158  and toward the first or second side  154 ,  156  of the heatsink  98 . 
     Referring now to  FIG. 8 , this embodiment differs from that of  FIG. 7  in that LED system  7  includes three LED modules  13 . A minimum lighting value such as a minimum acceptable lighting value is provided by two unregulated LED modules  80   a  arranged toward the first and second sides  154 ,  156  of the heatsink  98 . The unregulated LED modules  80   a  are powered by an unregulated LED driver 132   a  of the control system  9  for constantly illuminating the unregulated LED modules  80   a . A single regulated LED module  80   b  receives electrical power from a regulated LED driver  132   b  of the control system  9  for variably illuminating the regulated LED module  80   b  based on a detected temperature. The regulated LED module  80   b  is arranged between the unregulated LED modules  80   a . The heated zones  19  of the unregulated LED modules  80   a  are arranged at the upper portion  148  of the wall  100  of the heatsink  98 . The heated zone  19  of the regulated LED module  80   b  is arranged toward the lower portion  150  of the wall  100  of the heatsink  98 . In one embodiment, the heated zones  19  at the unregulated and regulated LED modules  80   a ,  80   b  are arranged at the lower and upper portions  150 ,  148  of the wall  100  of the heatsink  98 , respectively. 
     Referring now to  FIG. 9 , this embodiment differs from those of  FIGS. 7 and 8  in that the LED system  7  includes four LED modules  13 . A minimum lighting value such as a minimum acceptable lighting value is provided by two unregulated LED modules  80   a  arranged toward the first and second sides  154 ,  156  of the heatsink  98 . The unregulated LED modules  80   a  are powered by an unregulated LED driver 132   a  of the control system  9  for constantly illuminating the unregulated LED modules  80   a . Two regulated LED modules  80   b  receive electrical power from a regulated LED driver  132   b  of the control system  9  for variably illuminating the regulated LED modules  80   b  based on a detected temperature. The regulated LED modules  80   b  are arranged between the unregulated LED modules  80   a . The heated zone  19  of the unregulated LED module  80   a  toward the first side  154  of the heatsink  98  is arranged at the upper portion  148  of the wall  100  of the heatsink  98 . The heated zone  19  of the unregulated LED module  80   a  toward the second side  156  of the heatsink  98  is arranged at the lower portion  150  of the wall  100  the heatsink  98 . The heated zones  19  of the unregulated LED modules  80   a  may be arranged in the opposite orientation as that shown in  FIG. 9 . The heated zone  19  of the regulated LED module  80   b  nearest the first side  154  of the heatsink  98  is arranged at the lower portion  150  of the wall  100  of the heatsink  98 . The heated zone  19  of the regulated LED module  80   b  nearest the second side  156  of the heatsink  98  is arranged at the upper portion  148  of the wall  100  of the heatsink  98 . The heated zones  19  of the regulated LED modules  80   b  may be arranged in the opposite orientation as that shown in  FIG. 9 . 
     Referring now to  FIG. 10 , this embodiment differs from those of  FIGS. 7 and 8  in that the LED system  7  includes four LED modules  80 . The LED system  7  of  FIG. 10  is similar to that shown in  FIG. 9  in that a minimum lighting value such as a minimum acceptable lighting value is provided by two unregulated LED modules  80   a . The unregulated and regulated LED modules  80   a ,  80   b  are arranged in an alternating series across the heatsink  98 , as are the respective heated zones  19 . In this arrangement, an unregulated LED module  80   a  is provided at one of the first and second sides  154 ,  156  of the heatsink  98 . A regulated LED module  80   b  is provided at the other one of the first and second sides  154 ,  156  of the heatsink  98 . Each of an unregulated and a regulated LED module  80   a ,  80   b  is arranged in the intermediate portion  158  of the heatsink  98 . 
     Referring again to  FIGS. 7-10 , in one embodiment, the heatsink  98  defines a cooling capacity value that is greater than a heat-generating capability of the unregulated LED modules  80   a , but may be less than a summed heat-generating capability of the unregulated LED modules  80   a  combined with the heat-generating capability of the regulated LED modules  80   b . In this way, the heatsink  98  is always able to provide sufficient cooling for the LED system  7 , when the unregulated LED modules  80   a  are continuously operating. Operation of the regulated LED modules  80   b  is regulated to energize the regulated LED modules  80   b  to supplement illumination when the system temperature is below the maximum safe operating limit of the LED modules  13  and to reduce power to the regulated LED modules  80   b  when the system temperature reaches a threshold level while maintaining continuous operation of the unregulated LED modules  80   a . This allows for uninterrupted illumination from the LED system  7  while regulating temperature of the light source  70 . 
     Referring now to  FIG. 11  and with further reference to  FIGS. 1-2  and  7 - 10 , an exemplary method  160  of providing a high intensity lighting system controlled by a thermally responsive LED lighting control system  5  constructed in accordance with the present invention is depicted. As represented at block  162 , electrical power is delivered to at least one regulated LED  80   b  module so as to illuminate the LEDs of the regulated LED  80   b  module(s). This may be done by way of a regulated LED driver  132   b . As represented at block  164 , electrical power is delivered to at least one unregulated LED  80   a  module so as to illuminate the LEDs  15   b  ( FIG. 1 ) of the unregulated LED  80   a  module(s). This may be done by way of an unregulated LED driver  132   a . As represented at block  166 , a temperature within the light  22  is detected. This may include using one or more temperature sensors  18  to detect a temperature at a heat detection zone  17  which may be at a heated zone  19  of one or more of the LED modules  13  or a different location within the lamp  11 , such as at the heatsink  98 , reflector  30 , or other portion of the lamp  11 . As represented at block  168 , electrical power delivered to the regulated LED module  80   b  is reduced based at least in part on the detected temperature while maintaining an amount of electrical power delivered to the unregulated LED module  80   a . This may be done when the detected temperature reaches an upper threshold level, such as a maximum allowable use temperature for the LED modules  13  or a sub-threshold value such as temperature below but approaching the maximum allowable use temperature. The maximum allowable use temperature for the LED modules  13  and the upper threshold level value may be defined as a temperature above which solder joints or other components of the LED modules  13  become compromised, such as about 85° C., at which the control system  9  reduces power delivery to the regulated LED module(s)  80   b . A sub-threshold value may be used by the control system  9  to reduce power delivery to the regulated LED module(s)  80   b  at a detected temperature value that is less than the maximum allowable use temperature for the LED module  13 . For example, if a maximum allowable use temperature for the LED modules  13  is about 85° C., then the control system  9  may use a sub-threshold value of about 83° C. or about 80° C. to reduce power delivery to the regulated LED module(s)  80   b  to attenuate transfer of additional heat from the regulated LED modules  80   b  below the temperature at which the integrity of the LED modules  13  may become compromised. 
     The upper threshold level may also correspond to a temperature or rate of temperature change at which the heatsink  98  becomes heat soaked and can no longer shed heat faster than the heatsink  98  is absorbing heat. The reduction may be an on/off-type modulation or a throttling-type or dimming-type reduction in the amount of electrical power delivered to the regulated LED module(s)  80   b . The reduction may continue until the detected temperature drops below the upper threshold level or the reduction may continue until the detected temperature reaches a lower threshold level, at which point the regulated LED module(s)  80   b  are reenergized. The lower threshold level may be a temperature at or below which the heatsink  98  is able to suitably shed heat while maintaining the LED modules  13  at or below their maximum heat generating level. This defines a modulated cooling range between a thermal shutoff value at a value of an upper threshold level and a thermal-safe repower value. The modulated cooling range may be defined between a thermal shut off value and a thermal-safe repower value of between about 85° C. and 70° C. The upper threshold level and safe repower values may be defined by an upper threshold level value of 85° C. and a thermal-safe repower value of 80° C., an upper threshold level value of 83° C. and a thermal-safe repower value of 78° C., an upper threshold level value of 80° C. and a thermal-safe repower value of 75° C., or other ranges defined between combinations of upper threshold level and thermal-safe repower values of between about 85° C. and about 70° C. Block  170  represents the detected temperature being at or below the lower threshold level so that power is delivered to both the unregulated and regulated LED modules  80   a ,  80   b . Temperatures are subsequently and repeatedly detected, as are the above evaluations and controlling or regulating of the regulated LED module(s)  80   b  during use of the light tower  20 . 
     There are many possible variations contemplated regarding the construction of LED system  7  and the temperature control system  136 . For example, different numbers of unregulated and regulated LED modules  80   a ,  80   b  may be provided, such as more regulated LED modules  80   b  and unregulated LED modules  80   a  within a LED system  7 . The LED modules  13  may be arranged in a generally sideways or horizontal-type orientation, instead of the generally upright or vertical type orientation as shown. The unregulated LED modules  80   a  may be modulated by the control system  9  based on detected system temperature, but to a lesser extent than the regulated LED modules  80   b  modulated to ensure output or emission of an acceptable minimum lumen or lux lighting value as a result of operation of the thermally responsive LED lighting control system  5 . The lamp  11  may have a single LED module  13  that illuminates for providing light from the lamp  11 . The sole LED module  13  is modulated by the control system  9  for maintaining the LED module  13  at or below the threshold temperature value by controlling the amount of electrical power delivered to the LED module  13 , which may include modulating power delivered to all of the LEDs  15   b  or a subset of fewer than all of the LEDs  15   b  based on detected temperature within the lamp  11 , while maintaining at least some illumination from the lamp  11 . 
     In one preferred method of operating a lighting system such as a high output or high intensity lighting system shown in one or more of  FIGS. 2 ,  4 - 10  controlled by a thermally responsive LED lighting control system  5  where the high output or high intensity lighting system has at least one luminaire  11  with a plurality of light emitting LED modules  13  to maintain a desired minimum light output level from the lamp  11  under high temperature operating conditions, electrical power is delivered to the LED modules  13  causing light to be outputted from the lamp  11  at a first light output level, a temperature of the lamp  11  is detected, and the delivery of the electrical power to the LED modules  13  is controlled when the temperature exceeds a threshold supplying sufficient electrical power to maintain at least the minimum output level while allowing cooling to occur to reduce lamp temperature below the threshold. Where a high intensity lighting system controlled by a thermally responsive LED lighting control system  5  of the present invention has a plurality of such luminaires  11  each equipped with at least a plurality of LED modules  13 , electrical power delivery to each lamp  11  preferably is independent controlled to regulate the temperature of each lamp  11  independently of every other lamp  11 . 
     In one implementation of such a control method carried out when the threshold temperature is exceeded, electrical power delivered to at least one of the LED modules  13  of the lamp  11  is reduced while electrical power delivered to at least one other LED module  13  of the lamp  11  is not reduced such that the reduction of electrical power to the at least one of the LED modules  13  of the lamp  11  enables cooling of one or more LED modules  13  of the lamp  11  to occur reducing the lamp light output level below the maximum or first light output level while maintaining the lamp light output at or above the desired minimum light output level. In another control method implementation, delivery of electrical power to at least one of the LED modules  13  of the lamp  11  is ceased while delivery of electrical power to at least one other LED module  13  of the lamp  11  is maintained outputting light from the at least one other LED module  13  of the lamp  11  sufficient for the lamp light output level to meet or exceed the desired minimum light output level. 
     In one preferred control method implementation, the lamp  11  has a plurality of pairs of LED modules  13 , i.e., at least three LED modules  13 , with delivery of electrical power controlled when the threshold temperature is exceed by reducing electrical power to one of the plurality of pairs of LED modules  13  while not reducing electrical power to a plurality of the plurality of pairs of LED modules  13 . In one such control method implementation, delivery of electrical power is controlled to maintain delivery to a plurality of the plurality of pairs of LED modules  13  while stopping delivery of electrical power to at least one of the plurality of pairs of LED modules  13 . 
     When electrical power is delivered at the same time to each one of the plurality of LED modules  13  of a lamp  11 , such as during lamp startup and when the detected temperature is below the threshold temperature, light is outputted at the same time from all of the LED modules  13  of the lamp  11  causing the lamp  11  to output light at a first lumen output level that is greater than the minimum light output level, i.e., minimum lumen output level. When the same amount or magnitude of electrical power is delivered to each one of the plurality of LED modules  13  of a lamp  11  at the same time, such as during lamp startup and when the detected temperature is below the threshold temperature, a maximum lumen output level of light is outputted from each LED module  13  of the lamp  11  at the same time causing the lamp  11  to output light at a maximum lumen output level that is greater than the minimum light output level, i.e., minimum lumen output level. 
     A controller  140 , such as a control circuit equipped with a processor, e.g., microprocessor, microcontroller, etc., is used to monitor lamp temperature preferably by substantially continuously detecting a temperature of the lamp  11  during lamp operation within a zone of the lamp  11  that encompasses at least one of the LED modules  13  of the lamp  11  and which can encompass a plurality of the LED modules  13  of the lamp  11  thereby enabling LED module temperature(s) to be monitored. Such a controller  140  can be disposed onboard the lamp  11  or located remote from the lamp  11  but electrically connected thereto. Where one or more of the LED modules  13  of the lamp  11  are equipped with an onboard temperature sensor  18 , e.g., thermocouple, temperature detection can be accomplished by the controller monitoring the temperature of at least one of the LED modules  13  by detecting the temperature of the onboard temperature sensor  18  of at least one of the LED modules  13 . 
     The controller  140  can be configured to detect lamp temperature and control delivery of electrical power to the LED modules  13  of the lamp  11  when the threshold temperature is exceeded to reduce electrical power delivered to one or more LED modules  13  of the lamp sufficient to reduce the detected temperature without reducing lamp light output below a desired minimum light output level. In one preferred method implementation and embodiment, electrical power to one or more of the LED modules  13  of the lamp  11  is reduced or ceased until the detected temperature drops below the threshold while continuing to deliver electrical power to one or more of the LED modules  13  of the lamp  11  sufficient to output a light level of at least 40% of the total rated light output level of all of the LED lamps or modules  13  of the lamp  11  when all LED modules  13  are output light at the same time. Where a lamp  11  has three LED modules  13  each rated to output at least 4000 lumens for a total rated light output level of 12,000 lumens, delivery of electrical power to at least one of the LED modules  13  is controlled when threshold temperature is exceeded to reduce the lamp light output level below the total rated light output level of 12,000 lumens but maintain a lamp light output level that is at least 4800 lumens that is at least 40% of the total rated light output level of the lamp when all three LED modules  13  are operating. 
     In another preferred method implementation and embodiment, electrical power to one or more of the LED modules  13  of the lamp  11  is reduced or ceased until the detected temperature drops below the threshold while continuing to deliver electrical power to one or more of the LED modules  13  of the lamp  11  sufficient to output a light level of at least 50% of the total rated light output level of all of the LED lamps or modules  13  of the lamp  11  when all LED modules  13  are output light at the same time. Where a lamp  11  has three LED modules  13  each rated to output at least 4000 lumens for a total rated light output level of 12,000 lumens, delivery of electrical power to at least one of the LED modules  13  is controlled when threshold temperature is exceeded to reduce the lamp light output level below the total rated light output level of 12,000 lumens but maintain a lamp light output level that is at least 6000 lumens that is at least 50% of the total rated light output level of the lamp  11  when all three LED modules  13  are operating. 
     Various alternatives are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter regarded as the invention. It is also to be understood that, although the foregoing description and drawings describe and illustrate in detail one or more preferred embodiments of the present invention, to those skilled in the art to which the present invention relates, the present disclosure will suggest many modifications and constructions, as well as widely differing embodiments and applications without thereby departing from the spirit and scope of the invention.