Abstract:
The present disclosure relates to a programmable underwater lighting system for pools and spas. A plurality of underwater lights, each having a plurality of LEDs for producing light of various colors, a microprocessor for controlling the plurality of LEDs, and a memory in communication with the microprocessor containing one or more stored control programs, allow for the generation of various lighting effects in a pool or spa. A central controller is provided in communication with the plurality of underwater lights, and allows a user to define or select a desired lighting effect (such as a sequence, a fading effect, a “moving” color pattern, etc.) using a display and a keyboard. Optionally, a handheld remote control could be provided, in wireless communication with the central controller, for allowing a user to remotely control the plurality of lighting fixtures. When a desired lighting effect is defined by a user, the central controller transmits an instruction to each of the plurality of underwater lights instructing each light to execute a specific stored control program in its memory to produce the desired lighting effect. Each of the lights could be in communication with the central controller using a power line and an associated power line carrier data protocol, and each light could be provided with a thermal management system for monitoring the operating temperature of the light and automatically adjusting the brightness of the light to prevent dangerous temperatures.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 60/861,607, filed Nov. 28, 2006, the entire disclosure of which is expressly incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This invention relates to underwater lighting systems, and more particularly for lighting systems used in swimming pools, spas and the like for both safety and aesthetic purposes. 
         [0004]    2. Background of the Invention 
         [0005]    In-ground swimming pools and spas are often installed with lights, typically in a horizontal row a short distance below the waterline. The underwater lighting has a pleasing visual effect and permits safe swimming during nighttime. 
         [0006]    More recently, colored lights have been used, with programmable controllers for turning selected lights on and off, effectively producing an underwater light show for the pool&#39;s users. In a typical application, an underwater light fixture (also called a luminaire) includes an array of light-emitting diodes (LEDs) coupled to a microprocessor. A specific color is obtained by powering different LEDs in combinations of primary colors (e.g. LEDs in red, green and blue). A light fixture is turned on or off in accordance with a programmed sequence by alternately supplying and interrupting power to the light fixture. For example, as shown in  FIG. 1 , a light fixture  110  has an array of LEDs  100  controlled by a microprocessor  115 . Each light fixture has a power relay  116  for interrupting power from a power supply  118 . 
         [0007]    It is desirable to provide a programmable lighting system where the lights may turn on or off, change color and brightness, and/or appear to move, according to programmed sequences (including user-defined sequences) that do not depend on power interruption. 
       SUMMARY OF THE INVENTION 
       [0008]    In accordance with the present invention, a system is provided for programming and displaying lights, especially colored lights, in a swimming pool or spa installation and in associated landscape settings. In particular, a programmable lighting system is provided, including both hardware and software, which permits a user to adjust and control LED light displays; to adjust the speed at which color changes occur in a given light fixture; to use a pre-programmed light show with apparent movement of lights, or to program a new show, and to alter the speed thereof. Furthermore, the system permits the user to exploit these features with wet, dry or sporadic wet/dry fixtures or any combination thereof. Control systems for lighting fixtures may employ an RS-485 communication interface or Power Line Carrier (PLC) technology. In addition, control systems are described for driving LED lighting fixtures at either 12V or 110/120V. 
         [0009]    In accordance with another aspect of the invention, the system includes thermal management hardware and software for maintaining lighting component temperatures within rated safe operating temperatures, even when the temperature of a lighting fixture is non-uniform (for example, when a pool lighting fixture is partially submerged). 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0010]    Important features of the present invention will be apparent from the following Detailed Description of the Invention, taken in connection with the accompanying drawings, in which: 
           [0011]      FIG. 1  is a schematic illustration of a conventional light fixture including an LED array and a microprocessor; 
           [0012]      FIG. 2  schematically illustrates a lighting system constructed in accordance with an embodiment of the invention; 
           [0013]      FIGS. 3A-3E  are schematic illustrations of programmable systems of swimming pool, spa and landscape light fixtures, in accordance with additional embodiments of the invention; 
           [0014]      FIG. 4  is a schematic illustration of power connections between a controller unit and a set of swimming pool lights, in accordance with an embodiment of the invention; 
           [0015]      FIGS. 5 and 6  illustrate power connections in conventional swimming pool lighting installations; 
           [0016]      FIGS. 7A and 7B  are block diagrams of a controller unit in a 12 volt (V) pool lighting system according to an embodiment of the invention, which includes Power Line Carrier (PLC) communications between the controller unit and lighting fixtures; 
           [0017]      FIGS. 8A-8E  are schematic circuit diagrams of components of a 12V pool lighting system according to an embodiment of the invention, which includes serial RS-485 communications between the controller unit and lighting fixtures; 
           [0018]      FIG. 9  is a block diagram of a 12V AC pool lighting system using PLC communications between the controller unit and lighting fixtures, in accordance with an embodiment of the invention; 
           [0019]      FIGS. 10A-10F  are schematic circuit diagrams of components of the system of  FIG. 9 ; 
           [0020]      FIG. 11  is a block diagram of a 12V AC spa lighting system using PLC technology, in accordance with an embodiment of the invention; 
           [0021]      FIGS. 12A and 12B  are block diagrams of a controller unit in a 110/120V AC pool lighting system according to an embodiment of the invention, which utilizes PLC technology for communications between the controller unit and lighting fixtures; 
           [0022]      FIG. 13  is a block diagram of a 110/120V AC pool/spa lighting system using PLC technology, in accordance with an embodiment of the invention; 
           [0023]      FIGS. 14A-14B  are schematic circuit diagrams of a communications module using an RS-485 communications interface; 
           [0024]      FIGS. 15A-15B  are schematic circuit diagrams of a communications module using PLC technology and including a power line transceiver; 
           [0025]      FIG. 16  is a schematic illustration of a thermal management system employing thermistors mounted on an LED circuit board, in accordance with another embodiment of the invention; and 
           [0026]      FIGS. 17A-17C  are schematic circuit diagrams of a 12V communications module using PLC technology and including a power line transceiver. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0027]    Embodiments of the invention will be described with particular reference to lighting system components, programmable lighting displays, powering the lighting fixtures, and control systems for the lighting fixtures. 
         [0028]    Lighting System Components 
         [0029]      FIG. 2  schematically illustrates a lighting system  10  constructed in accordance with the present invention for use in connection with a swimming pool  12  and/or a spa  14 . More particularly, the lighting system  10  includes a plurality of light fixtures  16   a - 16   d ,  18   a - 18   d  mounted to side walls  20 ,  22 , respectively, of the pool  12 , as well as one or more light fixtures  24   a ,  24   b  mounted to side walls  26 ,  28 , respectively, of the spa  14 . The lighting system  10  is also equipped with a control system  30  which is connected to each of the light fixtures  16   a - 16   d ,  18   a - 18   d ,  24   a ,  24   b  for controlling the operation of the light fixtures  16   a - 16   d ,  18   a - 18   d ,  24   a ,  24   b . More particularly, the lighting system  10  is configured to communicate with the light fixtures  16   a - 16   d ,  18   a - 18   d ,  24   a ,  24   b  so as to cause a selected set or sets of the light fixtures to operate in one of a plurality of predetermined fashions, as will be discussed in greater detail hereinbelow. 
         [0030]    System components may be installed in various arrangements, as shown in  FIGS. 3A-3E .  FIG. 3A  illustrates a basic application in which a set of three fixtures (luminaires)  1 - 3  is installed below the waterline of a swimming pool  200 . The three fixtures are individually addressable and may be programmed for a variety of light displays as detailed below.  FIG. 3B  shows a variation in which fixture  1  is installed underwater in a spa  220  connected to pool  210 . It is not necessary for all of the luminaires to be of the same type; for example, as shown in  FIG. 3C , a set of three luminaires may include two underwater fixtures  1 ,  2  in pool  230  and a fixture outside the pool as a landscape feature (called a dry luminaire) A. Another type of luminaire is sporadically both wet and dry, for example a luminaire a′ installed in a fountain  240  as shown in  FIG. 3D . A lighting installation using a combination of wet, dry and wet/dry luminaires is shown schematically in  FIG. 3E . Swimming pool  250  has underwater luminaires  2 - 4 , and also has a spa  260  and a water feature (e.g. waterfall  270 ) connected thereto. This installation includes dry luminaires A-G and wet/dry luminaires a′-i′, arranged as desired with respect to the pool/spa landscaping and the water features. 
         [0031]    It should be noted that the various luminaires (wet, dry and wet/dry luminaires) may be programmed as a single set, or may be divided into subsets programmed separately so that, for example, a different light display may be run simultaneously on the fountain luminaires a′, b′, c′ and on the waterfall luminaires d′-i′. The software for programming the light displays, in accordance with embodiments of the invention, is discussed in more detail below. 
         [0032]    Programmable Lighting Displays 
         [0033]    With reference to  FIG. 2 , each of the light fixtures  16   a - 16   d ,  18   a - 18   d ,  24   a ,  24   b  has a construction and/or operation which are similar to those of light fixtures sold previously by the assignee of the present application, Hayward Industries, Inc., d/b/a Goldline Controls, Inc., under the trademark COLORLOGIC® (hereinafter “the prior COLORLOGIC® light fixtures”). For instance, each of the light fixtures  16   a - 16   d ,  18   a - 18   d ,  24   a ,  24   b  includes a plurality of light emitting diodes (LEDs) as a light generator and is adapted to be submersed underwater for providing underwater illumination. Each of the light fixtures  16   a - 16   d ,  18   a - 18   d ,  24   a ,  24   b  also includes a microprocessor and one or more solid state memories for storing preset light programs. Each of the programs is a list of colors (i.e., a set of steps) to be played back in order and a time between the steps. For example, a program might be specified as a series of one-second steps and the colors red, green, blue and white. The programs can include one or more of “animated” (i.e., color-changing) light programs, such as the light programs utilized in the prior COLORLOGIC® light fixtures under the names “VOODOO LOUNGE”, “TWILIGHT”, “TRANQUILITY”, “GEMSTONE”, “USA”, “MARDI GRAS” and “COOL CABARET”. When one of the color-changing programs is executed, each corresponding light fixture generates a lightshow by sequentially producing lights having predetermined colors. For example, when the “USA” program is triggered, the light fixture sequentially generates a light having the red color, a light having the white (clear) color, and a light having the blue color. In addition, the programs can include one or more fixed light programs, such as those utilized in the prior COLORLOGIC® light fixtures under the names “DEEP BLUE SEA”, “AFTERNOON SKY”, “EMERALD”, “SANGRIA” and “CLOUD WHITE”. When one of the fixed light programs is selected, the light fixtures produces a constant light having a fixed color (e.g., when the “DEEP BLUE SEA” program is selected, the light fixture transmits a constant light having a blue color). 
         [0034]    The control system  30  includes a controller  32  which is similar, in construction and operation, to pool/spa controllers sold by Hayward Industries, d/b/a Goldline Controls, Inc., under the trademark AQUA LOGIC® (hereinafter “the prior AQUA LOGIC® controllers”). For instance, the controller  32  includes a microprocessor and one or more memories. The controller  32  is connected to each of the light fixtures  16   a - 16   d ,  18   a - 18   d ,  24   a ,  24   b  for sending and receiving instructions and/or data to and from the light fixtures  16   a - 16   d ,  18   a - 18   d ,  24   a ,  24   b . Each of the light fixtures  16   a - 16   d ,  18   a - 18   d ,  24   a ,  24   b  is addressable by the controller  32  such that the light fixtures  16   a - 16   d ,  18   a - 18   d ,  24   a ,  24   b  can be controlled selectively and independently by the controller  32 . In this manner, one or more light fixtures  16   a - 16   d ,  18   a - 18   d ,  24   a ,  24   b  can be operated simultaneously by the controller to create a “moving” lightshow, as will be discussed further below. The controller also includes a display (e.g., a liquid crystal display) and a plurality of input keys for user interface. A wireless display keypad  33  may also be provided for remote, wireless user interface. 
         [0035]    The controller  32  can also be configured to control the operation of other pool/spa equipment. Such equipment can include pool and spa heaters, pumps, etc. (not shown in the figures). The controller  32  can be configured to control such equipment in the same basic manner as the prior AQUA LOGIC® controllers. 
         [0036]    The control system  30  also includes a communication device or board  34  for allowing the controller  32  to communicate with the light fixtures  16   a - 16   d ,  18   a - 18   d ,  24   a ,  24   b . The communication device  34  can be housed in a casing together with the controller  32  and can be constructed in any conventional manner which allows networking of the light fixtures  16   a - 16   d ,  18   a - 18   d ,  24   a ,  24   b  with the controller  32 . In an embodiment of the invention, communication device  34  utilizes networking through electrical power lines (e.g., hot and/or neutral lines connected to the light fixtures  16   a - 16   d ,  18   a - 18   d ,  24   a ,  24   b  for delivering electrical power thereto). More particularly, the communication device  34  receives signals from the controller  32  and transmits same to the light fixtures  16   a - 16   d ,  18   a - 18   d ,  24   a ,  24   b  through the power lines and vice versa. Alternatively, the communication device  34  can utilize communication through separate data lines (e.g., RS-485 or Ethernet cables). Other networking means (e.g., wireless and/or optical communications) can be utilized for allowing communication between the controller  32  and the light fixtures  16   a - 16   d ,  18   a - 18   d ,  24   a ,  24   b . The control system  30  may utilize the communication specification and commands discussed in attached Appendices A and B, which are incorporated herein and made part hereof. 
         [0037]    The controller  32  of the present invention is configured such that the light fixtures  16   a - 16   d ,  18   a - 18   d ,  24   a ,  24   b  can be assigned into one or more sets for the purpose of creating desired lightshows. For instance, the light fixtures  16   a - 16   d ,  18   a - 18   d  can be assigned to a set so as to create a lightshow that “moves” along the side wall  20  of the pool (see  FIG. 2 ), or jumps back and forth from the side wall  20  of the pool to the side wall  22  of the pool, as will be discussed in greater detail below. 
         [0038]    The operation of the lightshows can be configured by the user during the initial set-up or configuration of the controller. Once the controller is set up, the user can play with the operation of the programs by changing various parameters of the lightshows associated with the programs. These parameters include the brightness of the set of lights and the speed, direction and motion (program spread) of apparent motion of the lights (discussed further below). 
         [0039]    Lightshows can be “step” shows where the colors change abruptly from one program step to the next, or they can be “fade” shows where the colors blend from one step to the next. The following discussion applies equally to step or fade shows. 
         [0040]    As discussed above, each of the light fixtures includes one or more light programs, each of which is a list of colors (a set of steps) to play back in order, and a time between the steps. For example, a program might be specified as one-second steps and the colors red, green, blue and white. The user may change the speed of the lightshow associated with a particular program (speed up or slow down) by factors of 2 from a minimum of 1/16 normal speed to a maximum of 16 times normal speed. 
         [0041]    Configuration of the Control System 
         [0042]    During configuration, the light fixtures are assigned to a set and assigned a specified sequence in the set. Typically, the user draws a diagram of the pool and the spa and decides which light fixtures should operate as a collection or set of light fixtures. Collections can overlap, and the system is configured to make reasonable sense out of the overlapping cases. 
         [0043]    In a set of light fixtures, the user can decide what sequence each light will be in a show. If the light fixtures  16   a - 16   d ,  18   a - 18   d  (i.e., eight light fixtures in the pool, four on each side) are assigned to a set, the user can choose that the sequence go down both sides of the pool at once by assigning to the light fixtures  16   a - 16   d ,  18   a - 18   d  the sequence of Table 1 (see below). Alternatively, the user can choose that the sequence go around the pool in a circle by assigning the sequence of Table 2 below, or to jump back and forth from side to side by using the sequence of Table 3 below. The setup can be different for each set of light fixtures. The same eight physical light fixtures can be in multiple sets. 
         [0000]    
       
         
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 Sequence Nos. 
                 Light Fixtures 
               
               
                   
               
             
             
               
                 1 
                 Light Fixtures 16a, 18a 
               
               
                 2 
                 Light Fixtures 16b, 18b 
               
               
                 3 
                 Light Fixtures 16c, 18c 
               
               
                 4 
                 Light Fixtures 16d, 18d 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                 Sequence Nos. 
                 Light Fixtures 
               
               
                   
               
             
             
               
                 1 
                 Light Fixture 16a 
               
               
                 2 
                 Light Fixture 16b 
               
               
                 3 
                 Light Fixture 16c 
               
               
                 4 
                 Light Fixture 16d 
               
               
                 5 
                 Light Fixture 18d 
               
               
                 6 
                 Light Fixture 18c 
               
               
                 7 
                 Light Fixture 18b 
               
               
                 8 
                 Light Fixture 18a 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
               
             
           
               
                 TABLE 3 
               
               
                   
               
               
                 Sequence Nos. 
                 Light Fixtures 
               
               
                   
               
             
             
               
                 1 
                 Light Fixture 16a 
               
               
                 2 
                 Light Fixture 18a 
               
               
                 3 
                 Light Fixture 16b 
               
               
                 4 
                 Light Fixture 18b 
               
               
                 5 
                 Light Fixture 16c 
               
               
                 6 
                 Light Fixture 18c 
               
               
                 7 
                 Light Fixture 16d 
               
               
                 8 
                 Light Fixture 18d 
               
               
                   
               
             
          
         
       
     
         [0044]    All the light fixtures in the pool are individually addressable. During the setup phase all light fixtures in a particular set are told which program they will be running, at what speed, and with what “motion parameter”. That is, each light fixture can be a member of several sets, and the sets are allowed to overlap. As mentioned previously, the homeowner may speed up or slow down the lightshows in the range of 1/16 to 16 times normal speed. 
         [0045]    A more detailed discussion of setup steps appears in Appendix C, which is incorporated herein and made part hereof. 
         [0046]    Apparent Movement of Light 
         [0047]    The lighting system  10  of the present invention is adapted to cause a lightshow program of some number of steps, running on a set of light fixtures, appear to have movement. For example, the program can be four distinct colors each displayed for one second. There are four light fixtures on the pool along one wall, each running the same program but they are started up one second apart. Under these conditions, an observer would say that the four colors were moving across the light fixtures. 
         [0048]    If all four light fixtures start the program at the same time, they will all be showing the same colors at the same time, and there will be no apparent movement of color. However, if each light fixture in sequence starts the program a half second apart, the colors will appear to be spread out across two light fixtures as it moves, and fewer colors will be shown at any given time. In this case, the program specified one second steps, and the delay between starting adjacent light fixtures is one second, so the motion is one light at a time. 
         [0049]    The concept of “one program step per light” makes more sense than “one second per light”. For example, what happens to the motion in the case where the user tells the program to run faster? If one maintains a one second delay, the results are completely different. It makes more sense to think about movement in multiples of a program step than in terms of time. 
         [0050]    Motion Parameter 
         [0051]    The motion parameters allows the homeowner to specify how much movement a lightshow should have in a way that is independent of the step time of the program, or of the speedup or slowdown in the show playback that the homeowner might make. 
         [0052]    The control system is configured such that a motion parameter of zero (i.e., OFF) means no motion. That is, all the light fixtures in the set run the same program at the same time (e.g., if all of the light fixtures in the pool are assigned to the same set, the whole pool changes color in a pattern set by the program). Accordingly, if the light fixtures  16   a - 16   d  are assigned to a set and are instructed to execute a program with a set of one-second steps corresponding to the colors red, green, blue and white, the lightshow shown in following Table 4 may be observed. 
         [0000]    
       
         
               
               
               
               
               
             
           
               
                 TABLE 4 
               
               
                   
               
               
                   
                 Light 
                 Light 
                 Light 
                 Light 
               
               
                   
                 Fixture 16a 
                 Fixture 16b 
                 Fixture 16c 
                 Fixture 16d 
               
               
                 Time 
                 (Sequence 
                 (Sequence 
                 (Sequence 
                 (Sequence 
               
               
                 Interval 
                 No. 1) 
                 No. 2) 
                 No. 3) 
                 No. 4) 
               
               
                   
               
             
             
               
                 0 
                 Red 
                 Red 
                 Red 
                 Red 
               
               
                 1 
                 Green 
                 Green 
                 Green 
                 Green 
               
               
                 2 
                 Blue 
                 Blue 
                 Blue 
                 Blue 
               
               
                 3 
                 White 
                 White 
                 White 
                 White 
               
               
                 4 
                 Red 
                 Red 
                 Red 
                 Red 
               
               
                 5 
                 Green 
                 Green 
                 Green 
                 Green 
               
               
                 6 
                 Blue 
                 Blue 
                 Blue 
                 Blue 
               
               
                 7 
                 White 
                 White 
                 White 
                 White 
               
               
                   
               
             
          
         
       
     
         [0053]    The control system can be configured such that a motion parameter of one means that “normal motion” occurs. This means that each light in sequence will be one step ahead of its neighbor. This type of show will have a color moving down the row of light fixtures, one light at a time. For instance, if the light fixtures  16   a - 16   d  are assigned to a set and are instructed to execute a program with a set of one-second steps corresponding to the colors red, green, blue and white, the lightshow illustrated in following Table 5 may be observed. As can be seen in Table 5, the colors red, green, blue and white appear to move down along the light fixture  16   a - 16   d  (see, e.g., the cross-hatched cells in Table 5). 
         [0000]    
       
         
               
               
               
               
               
             
           
               
                 TABLE 5 
               
               
                   
               
               
                 Time 
                 Light 
                 Light 
                 Light 
                 Light 
               
               
                 Interval 
                 Fixture 16a 
                 Fixture 16b 
                 Fixture 16c 
                 Fixture 16d 
               
               
                 (Program 
                 (Sequence 
                 (Sequence 
                 (Sequence 
                 (Sequence 
               
               
                 Steps) 
                 No. 1) 
                 No. 2) 
                 No. 3) 
                 No. 4) 
               
               
                   
               
             
             
               
                 0 
                 Red 
                 White 
                 Blue 
                 Green 
               
               
                 1 
                 Green 
                 Red 
                 White 
                 Blue 
               
               
                 2 
                 Blue 
                 Green 
                 Red 
                 White 
               
               
                 3 
                 White 
                 Blue 
                 Green 
                 Red 
               
               
                 4 
                 Red 
                 White 
                 Blue 
                 Green 
               
               
                 5 
                 Green 
                 Red 
                 White 
                 Blue 
               
               
                 6 
                 Blue 
                 Green 
                 Red 
                 White 
               
               
                 7 
                 White 
                 Blue 
                 Green 
                 Red 
               
               
                   
               
             
          
         
       
     
         [0054]    With the same program illustrated in Table 5, a lightshow which moves along the side walls of the pool can be achieved with the use of the set of light fixtures and sequence shown in Table 1 above. Such a lightshow is illustrated in following Table 6. 
         [0000]    
       
         
               
               
               
               
               
             
           
               
                 TABLE 6 
               
               
                   
               
               
                   
                 Light 
                 Light 
                 Light 
                 Light 
               
               
                 Time 
                 Fixtures 
                 Fixtures 
                 Fixtures 
                 Fixtures 
               
               
                 Interval 
                 16a, 18b 
                 16b, 18b 
                 16c, 18c 
                 16d, 18d 
               
               
                 (Program 
                 (Sequence 
                 (Sequence 
                 (Sequence 
                 (Sequence 
               
               
                 Steps) 
                 No. 1) 
                 No. 2) 
                 No. 3) 
                 No. 4) 
               
               
                   
               
             
             
               
                 0 
                 Red 
                 White 
                 Blue 
                 Green 
               
               
                 1 
                 Green 
                 Red 
                 White 
                 Blue 
               
               
                 2 
                 Blue 
                 Green 
                 Red 
                 White 
               
               
                 3 
                 White 
                 Blue 
                 Green 
                 Red 
               
               
                 4 
                 Red 
                 White 
                 Blue 
                 Green 
               
               
                 5 
                 Green 
                 Red 
                 White 
                 Blue 
               
               
                 6 
                 Blue 
                 Green 
                 Red 
                 White 
               
               
                 7 
                 White 
                 Blue 
                 Green 
                 Red 
               
               
                   
               
             
          
         
       
     
         [0055]    With the light fixtures  16   a - 16   d  and  18   a - 18   d  mounted to the side walls of the pool, the user can choose to have the lightshow movement around the pool in a circle by using the sequence of Table 2 above. Alternatively, the lightshow movement can be set to jump back and forth from side to side by using the sequence of Table 3 above. 
         [0056]    As discussed above, a motion value of zero (i.e., OFF) means all the light fixtures will do the same thing, while a motion value of one means one full step between light fixtures. Motion values falling between zero and one mean that there is less than one full step between adjacent light fixtures. In this case, the program step will overlap two light fixtures. As a result, instead of one light showing one color, it will be spread across several light fixtures. If thought in terms of bands of color, it comes out the following way: motion parameter zero means the band of color covers all the light fixtures, motion parameter one means the band is one light wide, and in between, the band is several light fixtures wide. 
         [0057]    Motion parameters can vary between preset values (e.g., motion values of zero to 1.2). Values less than one mean “overlap”, and values greater than one means “underlap”. For motion values greater than 1, adjacent light fixtures are more than one step apart. 
         [0058]    Motion values can be either negative or positive. Positive motion values mean that the apparent movement will be in the ascending order of the sequence numbers assigned to the light fixtures in the set (see Tables 5 and 6 above). Negative motion values mean that the apparent motion will be in the opposite direction (i.e., in the descending order). 
         [0059]    The control system of the present invention can be configured such that the motion parameter can be adjusted on-the-fly while a lightshow is running. Such adjustment may produce dramatically different visual effects. Additionally, it is noted that the motion parameter could be used with lighting programs having variable step sizes. In such circumstances, the lighting program would include a parameter which indicates a standard shifting time, or a default step size, which could be used for motion calculations by the lighting program. 
         [0060]    The control system also allows the user to select the brightness of the set of lights (e.g., by scaling brightness parameters associated with one or more color values), and to select fixed colors which can each be recalled. These colors are sometimes called “favorite colors”. This is done by allowing the user to change the fixed colors that come with the system. The control system may include one or more programs which permits the user to program one or more custom movement shows. The user can use the “favorite colors” to build a movement show. For instance, the user can pick five custom colors, and put them together into a movement show by using one of these programs. One runs them as a step show, one as a fade show. Color mixing in a light show can be achieved by controlling the brightness of a mix of red, green, and blue values, and overall brightness can be controlled by scaling the color mix (e.g., red, green, and blue values) up or down by desired amounts. 
         [0061]    In order to start one of the light programs stored in the control system, the user presses an aux button (or a timer turns on the aux) on the controller, which is programmed to run a particular program with a particular set of light fixtures during configuration. A message is broadcast by the communication system to all light fixtures assigned to the aux button telling them that they should start the program number they have stored. Each light fixture looks at its sequence number (its place in the show). Its sequence number determines where in the show it starts. In other words, the light applies a formula to its sequence number to see at what step in the lightshow program it should start executing. The determination is in two steps. First, it determines what its offset would be if the motion parameter were one (normal offset), then it calculates a change to that number based on the motion parameter. The formula makes use of the modulo operator, “%”. The formula is the sum of a base offset and a motion offset which are calculated as follows: 
         [0000]      Base offset=(# of program steps−(sequence # % # of program steps)) % # of program steps; 
         [0000]      and 
         [0000]      Motion offset=(1−motion factor)×sequence #, if result is less than zero, add # of program steps. 
         [0000]    The resulting number may be a fractional step number. In this case, the software handles getting the time pointer to an intermediate step. The software runs the light show program very quickly to get to the desired starting location, then goes to normal operation. 
         [0062]    All of this is done in response to a command from the controller to start up an aux button, as part of communications processing. Once the startup is handled, the main software loop handles updating the light shows. The main loop sees if incoming communications data needs to be processed and if the light show program needs to move to next step. 
         [0063]    In view of the foregoing description, it will be appreciated that a user of a programmable lighting system in accordance with an embodiment of the invention may adjust the rate of change of light emitted from a light fixture; adjust the speed of a pre-programmed, color-changing light show; adjust the brightness of the light emitted by a set of lights; build a light show using selected custom colors; and adjust and control the speed of color transitions between light fixtures, thereby orchestrating the apparent movement of colors among multiple lights. The foregoing adjustability, as well as other user-adjustable features, are discussed in attached Appendix D, which is incorporated herein by reference and made part hereof. 
         [0064]    Powering the Lighting Fixtures 
         [0065]    As mentioned above with reference to  FIG. 2 , the various lighting fixtures are powered from controller  32  by hot and/or neutral lines connected to the lighting fixtures. In another embodiment, shown schematically in  FIG. 4 , lighting fixtures  1 - 6  along the sidewalls of pool  40  each have a pair of power lines  41   a ,  41   b  (e.g., in an AC system, one hot line and one neutral line; or, in a transformer or DC system, two power lines) connected to a distribution box  43  which in turn is connected by a pair of power lines  45   a ,  45   b  to controller  42 . The controller includes a communication board (COM)  44 . This arrangement of power lines allows wiring of the lighting fixtures to a centralized location adjacent to the pool. This arrangement is in contrast to the conventional arrangement of  FIG. 5 , in which multiple hot connections  51  are made between the controller  52  and the fixtures while a single neutral connection  53  is shared among the fixtures. The embodiment shown in  FIG. 4  also may be contrasted with the conventional arrangement shown in  FIG. 6 , in which a separate pair of power lines, each including a unique hot connection  61  and neutral connection  63 , is provided from the controller  62  to each light fixture. 
         [0066]    Details of Lighting Systems 
         [0067]    In embodiments of the invention, a pool/spa/landscape lighting system includes a controller and a communication board and delivers power at either 12V AC or 110/120V AC to a set of lighting fixtures, with the controller and communication board connected using an RS-485 communication interface. In other embodiments of the invention, communication from the controller uses Power Line Carrier (PLC) technology. Details of these embodiments are given below. 
         [0068]      FIGS. 7A and 7B  are schematic block diagrams of a 12V AC control system  70  for a pool/spa/landscape lighting installation, including a power supply  71 , controller  72 , and communication board  75 , according to an embodiment of the invention. The controller  72  delivers power to the communication board  75  at 10V DC, and directs signals to the communication board using an RS-485 communication interface  73 . A set of circuit breakers  74  connect line power at 120V AC to 12 V transformers  76  to deliver low-voltage power to the pool lighting fixtures (not shown). As shown schematically in  FIG. 7B , system  70  is divided into a low-voltage region  70 L and a high-voltage region  70 H. The communication board  75  is coupled to the lighting fixtures using a Power Line Carrier coupling  78 , so that both power and signals are carried by the hot and neutral leads to each fixture. 
         [0069]    The communications board  75  includes a microprocessor  77 . The microprocessor has stored therein networking communication software and the protocol for the PLC communications between the communication board and the lighting fixtures. As discussed below, each lighting fixture also includes a microprocessor and a communications circuit which allows for PLC communications with the controller  72 , in addition to thermal management software. The thermal management software controls the intensity of the light according to whether the light is above the waterline or below the waterline. 
         [0070]    As shown in  FIGS. 7A and 7B , the controller  72  includes a display and keypad accessible by a user, so that software menus may be presented to the user (e.g. a list of available lightshow programs), and so that a user may devise new lightshow programs and input them. It is noteworthy that the control system provides one-stage power conversion for the low-voltage lighting fixtures; that is, transformers  76  convert line current directly to 12V AC power for driving the LEDs in the lighting fixtures. 
         [0071]      FIGS. 8A-8E  are schematic circuit diagrams of components of a 12V pool lighting system according to an embodiment of the invention, which includes serial RS-485 communications between the controller unit and lighting fixtures. Microprocessor  77 , shown in FIG.  8 A 1 , outputs POWER ENABLE signals  83  and PWM signals  84  (see FIG.  8 A 2 ) for controlling the LED driver circuits in the various lighting fixtures. The microprocessor links to the controller  72  via the RS-485 interface  73 . 
         [0072]    Additional components of the system are shown in FIGS.  8 B 1 - 8 B 4 . FIG.  8 B 1  shows the respective power and drive connections to arrays of red, blue and green LEDs in the lighting fixtures. FIG.  8 B 2  shows a multiphase clock generator for use in switching the LEDs. FIGS.  8 B 3 - 8 B 4  show a power conversion switching circuit and associated power supply circuitry for use in supplying power to the lighting fixtures, as well as temperature detection and shutdown circuitry (see FIG.  8 B 4 ).  FIGS. 8C ,  8 D and  8 E show the LED driver circuits for the red, green and blue LEDs of the lighting fixtures respectively. Each driver circuit includes an integrated LED driver device  88  (e.g. linear converter LTC3783 from Linear Technology, Inc.). Device  88  turns on and off in accordance with the POWER ENABLE signal from microprocessor  77 . 
         [0073]      FIG. 9  is a schematic block diagram of a 12V AC lighting system, in accordance with another embodiment of the invention, wherein communications between the controller and lighting fixtures is established using PLC communications. An AC power supply  90  is connected to a PLC communications device  91  and an electromagnetic interference (EMI) filter  93 . The PLC communications device  91  and logic power supply  92  are connected to microprocessor  96 . DC power is delivered to the LED driver circuits  97 ,  98 ,  99  (one each for red, green and blue LEDs) via bridge link capacitor circuit  94 , which serves as a rectifier for the AC power supply. The LED driver circuits are also connected to the microprocessor  96  and to multiphase oscillator  95 . 
         [0074]    FIGS.  10 A 1 - 10 A 4  are schematic diagrams showing details of the microprocessor  96  in this embodiment. The microprocessor outputs POWER ENABLE and PWM signals  103 ,  104  to the LED driver circuits, and has a link to an IC transceiver  102  (see FIG.  10 A 4 ) which permits network control over power lines. Such a transcevier may be a PL3120 transceiver from Echelon, Inc., or a Lonworks Transceiver Model G1-011034A-1. 
         [0075]    Details of power supply  92  (including circuit  92   a  for producing 10V DC and 5V DC and circuit  92   b  for producing 3.3V DC), as well as circuit  94 , multiphase clock generator  95 , color LED chains, and associated power supply and test point circuitry, are shown in FIGS.  10 B 1 - 10 B 6  and  10 F. The LED driver circuits  97 ,  98 ,  99  for red, green and blue LEDs are shown in  FIGS. 10C-10E , respectively. Each of these circuits includes a linear boost converter  108  such as LTC3783 from Linear Technology, Inc. 
         [0076]      FIG. 11  is a schematic block diagram for a 12V AC spa lighting system, in accordance with still another embodiment of the invention. The components and connections are similar to the system of  FIG. 9 , except that a voltage doubler  111  is used in place of circuit  94 , so that voltage in the range of 28-36V DC is delivered to the LED driver circuits  112 ,  113 ,  114  for driving red, green and blue LEDs respectively. Circuits  112 ,  113 ,  114  accordingly include a buck converter (DC-DC step down converter) such as UCC3809 from Texas Instruments, Inc. Each driver circuit is configured to drive four LEDs of the respective color. 
         [0077]      FIGS. 12A and 12B  are schematic block diagrams of a 120V AC lighting system, in accordance with a further embodiment of the invention. This system is similar in construction to the system of  FIGS. 7A and 7B , but does not include 12V transformers. System  120  includes power supply  121 , controller  122 , and communication board  125 . The controller  122  delivers power to the communication board  125  at 10V DC, and directs signals to the communication board using an RS-485 communication interface  123 , as in the previous embodiment. A set of circuit breakers  124  connect line power at 120V AC to a set of 120V pool lighting fixtures. In this embodiment, up to 32 lighting fixtures may be controlled from system  120 . As shown schematically in  FIG. 7B , the communication board  125  is coupled to the lighting fixtures using a Power Line Carrier coupling  128 , so that both power and signals are carried by the hot and neutral leads to each fixture. 
         [0078]    The communications board  125  includes a microprocessor  127 . As in the previous embodiment, the microprocessor has stored therein thermal management software; networking communication software; and the protocol for the PLC communications between the communication board and the lighting fixtures. As shown in  FIGS. 12A and 12B , the controller  122  includes a display and keypad accessible by a user, so that software menus may be presented to the user (e.g. a list of available lightshow programs), and so that a user may devise new lightshow programs and input them. 
         [0079]    A 120V AC system is preferable to a 12V AC system in some applications, since it is easier to install and may support more light fixtures than a similarly sized 12V system. However, a 12V system may be required in some localities because of safety concerns. 
         [0080]      FIG. 13  is a schematic block diagram of a 110V AC pool/spa combination lighting system, according to another embodiment of the invention. The components and connections are similar to those shown in  FIG. 9 , except that the LED driver circuits  131 ,  132 ,  133  have buck converters instead of boost converters, for reducing the DC voltage (generally in the range of about 125V to 182V DC). Extra lighting fixtures may be controlled with this system in comparison with the system of  FIG. 9  (e.g. 10 LEDs of each color for a pool, and an additional 4 LEDs of each color for a spa). 
         [0081]      FIGS. 14A-14B  show general schematic views of a communications board according to the present invention using an RS-485 communication interface, for use in the central controller. In this embodiment, communications with the lights is achieved using serial RS-485 wired connections between the lights and the controller. A Linear Technology LTC1535ISW isolated RS-485 transceiver could be used for this purpose, as shown in  FIG. 14B . A similar communications board/circuit could be used in each lighting fixture. 
         [0082]      FIGS. 15A-15B  show general schematic views of a communications board according to the present invention using PLC technology, for use in the central controller of the present invention. In this embodiment, communications with the lights is achieved using PLC communications over power lines interconnecting the controller and the lights. A PL3120 PLC transceiver chip, manufactured by Eschelon, Inc., could be used for this purpose. A similar communications board/circuit could be used in each lighting fixture. 
         [0083]      FIGS. 17A-17C  show general schematic views of communications boards according to the present invention using low-voltage (e.g., 12V) PLC technology, for use in the central controller of the present invention. In this embodiment, communications with the lights is achieved using PLC communications over low-voltage power lines interconnecting the controller and the lights. A PL3120 PLC transceiver chip, manufactured by Eschelon, Inc., could be used for this purpose, with appropriate low-voltage transformers (see  FIG. 17C ). A similar communications board/circuit could be used in each lighting fixture. 
         [0084]    Thermal Management of Lighting Fixtures 
         [0085]    In a further embodiment of the invention, a thermal management system protects the LED lighting fixtures from overheating. A typical pool/spa lighting arrangement relies on water to keep lighting components of a luminaire (specifically, the circuit cards on which the light-emitting devices are mounted) within rated operating temperatures. Such components are susceptible to overheating if the luminaire is not submerged or partially submerged, unless the current delivered to them is interrupted. 
         [0086]    In this embodiment of the invention, a thermal sensor shuts off the microprocessor of the lighting fixture if an abnormally high temperature is detected. In addition, surface mount thermistor components are installed on the LED mounting board, and a software algorithm is used to automatically reduce the LED intensity as needed to maintain safe operating temperatures. Thus, if the luminaire is dry, the LEDs will automatically be dimmed to the extent needed to prevent overheating of any components. 
         [0087]    In an embodiment, four surface-mount thermistors  160  are mounted on the same circuit board  161  as the LEDs in each lighting fixture, as shown in  FIG. 16 . The thermistors are mounted at conveniently spaced locations at the edge of the area on the board where the LEDs are mounted. Thus, with the LEDs placed roughly in a circular area  162  in the center of the circuit board  161 , the thermistors  160  may be at the 12, 3, 6, and 9 o&#39;clock positions. The thermistors are connected to a bias circuit and to analog inputs of the microprocessor (e.g. microprocessor  77  in  FIG. 7A ). An analog to digital converter (ADC) samples the four thermistor inputs and assigns a numeric value to the measured voltage, so that the four measured voltages represent the temperature on the LED circuit board. 
         [0088]    A software algorithm is executed whereby the four temperature readings are compared periodically (with a preset sampling interval), and the highest of the four readings is compared to a firmware threshold variable. If this highest reading is above the threshold, the algorithm causes the light output setting of all three LED channels (red/blue/green) to be reduced according to a proportion of the total output. This proportion (that is, the degree of reduction of the output setting) does not have a fixed value, but rather is computed based on excess temperature and the measured rate of temperature increase. If the temperature of an LED circuit board is rapidly rising, the reduction in the output setting will thus be more dramatic than if the temperature is rising slowly. If the temperature reading is only slightly above the threshold, the degree of reduction will be less than if the reading is substantially above the threshold. 
         [0089]    At the next sampling interval, the algorithm is applied again. If the maximum of the four temperature readings remains above the threshold, the light output setting is reduced further. Conversely, if the maximum temperature reading is below the threshold, the light intensity may be proportionately increased. 
         [0090]    The increase or decrease in the light output setting may be implemented by multiplying the computed proportion by the ‘intensity’ or ‘brightness’ user setting which is stored in memory. The original user setting is thus preserved, so that the output setting chosen by the user may be restored at a later time if the thermal management system temporarily reduces the light output. 
         [0091]    A failsafe circuit may also be provided so that if there is any abnormal interruption in execution of the thermal management software, the luminaire will be shut off. 
         [0092]    The above-describe thermal management system maintains the LED component temperatures within rated safe operating temperatures. If the temperature of a lighting fixture is non-uniform (e.g. a pool lighting fixture partially submerged), the system will nonetheless protect the components by managing the temperature based on the hottest thermistor. It is noteworthy that this system does not require any particular mounting orientation (“upright” or otherwise) for the luminaire. 
         [0093]    It will be appreciated that a programmable lighting system as described above, in its various hardware and software embodiments, permits a user to adjust and control LED light displays; to adjust the speed at which color changes occur in a given light fixture; to use a pre-programmed light show, or to program a new show, and to alter the speed thereof; and to use all of these features with wet, dry or sporadic wet/dry fixtures or any combination thereof. Accordingly, the above-described embodiments offer significant advantages relative to the present state of the art. 
         [0094]    It is noted that the present invention could include an authentication feature which allows the central controller, the communication board in the central controller, and each of the plurality of lights, to ascertain and verify the identities of associated hardware components. For example, the plurality of lights and the communication board could be programmed to bi-directionally communicate with each other so as to verify that only authorized communication boards and lights are being utilized. Similarly, the communication board and the central controller could be programmed to bi-directionally communication with each other so as to verify that only authorized communications boards and central controllers are being utilized. 
         [0095]    Importantly, the user interface (e.g., display and keyboard) of the central controller of the present invention allows a user to create his or her own custom lighting program. This allows the user to specify desired colors from a palette or spectrum of colors, as well as to specify desired sequences, steps, effects, and/or motion parameters. The user can thus create his or her own customized lighting effect in a body of water. 
         [0096]    While the invention has been described in terms of specific embodiments, it is evident in view of the foregoing description that numerous alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the invention is intended to encompass all such alternatives, modifications and variations which fall within the scope and spirit of the invention. What is desired to be protected by Letters Patent is set forth in the appended claims.