DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

[0105] The structure and operation of various methods and systems that are embodiments of the invention will now be described. It should be understood that many other ways of practicing the invention herein are available, and the embodiments described herein are exemplary and not limiting.

[0106] Referring to FIG. 1, a light module 100 is depicted in block diagram format. The light module 100 includes two components, a processor 16 and an LED system 120 , which is depicted in FIG. 1 as an array of light emitting diodes. The term “processor” is used herein to refer to any method or system for processing in response to a signal or data and should be understood to encompass microprocessors, integrated circuits, computer software, computer hardware, electrical circuits, application specific integrated circuits, personal computers, chips, and other devices capable of providing processing functions. The LED system 120 is controlled by the processor 16 to produce controlled illumination. In particular, the processor 16 controls the intensity of different color individual LEDs, semiconductor dies, or the like of the LED system 120 to produce illumination in any color in the spectrum. Instantaneous changes in color, strobing and other effects, more particularly described below, can be produced with light modules such as the light module 100 depicted in FIG. 1 . The light module 100 may be made capable of receiving power and data. The light module 100 , through the processor 16 , may be made to provide the various functions ascribed to the various embodiments of the invention disclosed herein.

[0107] Referring to FIG. 2 , the light module 100 may be constructed to be used either alone or as part of a set of such light modules 100 . An individual light module 100 or a set of light modules 100 can be provided with a data connection 500 to one or more external devices, or, in certain embodiments of the invention, with other light modules 100 . As used herein, the term “data connection” should be understood to encompass any system for delivering data, such as a network, a data bus, a wire, a transmitter and receiver, a circuit, a video tape, a compact disc, a DVD disc, a video tape, an audio tape, a computer tape, a card, or the like. A data connection may thus include any system of method to deliver data by radio frequency, ultrasonic, auditory, infrared, optical, microwave, laser, electromagnetic, or other transmission or connection method or system. That is, any use of the electromagnetic spectrum or other energy transmission mechanism could provide a data connection as disclosed herein. In embodiments of the invention, the light module 100 may be equipped with a transmitter, receiver, or both to facilitate communication, and the processor 16 may be programmed to control the communication capabilities in a conventional manner. The light modules 100 may receive data over the data connection 500 from a transmitter 502 , which may be a conventional transmitter of a communications signal, or may be part of a circuit or network connected to the light module 100 . That is, the transmitter 502 should be understood to encompass any device or method for transmitting data to the light module 100 . The transmitter 502 may be linked to or be part of a control device 504 that generates control data for controlling the light modules 100 . In an embodiment of the invention, the control device 504 is a computer, such as a laptop computer. The control data may be in any form suitable for controlling the processor 16 to control the LED system 120 . In embodiment of the invention, the control data is formatted according to the DMX-512 protocol, and conventional software for generating DMX-512 instructions is used on a laptop or personal computer as the control device 504 to control the light modules 100 . The light module 100 may also be provided with memory for storing instructions to control the processor 16 , so that the light module 100 may act in stand alone mode according to pre-programmed instructions.

[0108] Turning to FIG. 3 , shown is an electrical schematic representation of the light module 100 in one embodiment of the present invention. FIGS. 4 and 5 show the LED-containing side and the electrical connector side of an exemplary embodiment of such a light module 100 . Light module 100 may be constructed, in an embodiment, as a self-contained module that is configured to be a standard item interchangeable with any similarly constructed light module. Light module 100 contains a ten-pin electrical connector 110 of the general type. In this embodiment, the connector 110 contains male pins adapted to fit into a complementary ten-pin connector female assembly, to be described below. Pin 180 is the power supply. A source of DC electrical potential enters light module 100 on pin 180 . Pin 180 is electrically connected to the anode end of light emitting diode (LED) sets 120 , 140 and 160 to establish a uniform high potential on each anode end.

[0109] LED system 120 includes a set 121 of red LEDs, a set 140 of blue LEDs, and a set 160 of green LEDs. The LEDs may be conventional LEDs, such those obtainable from the Nichia America Corporation. These LEDs are primary colors, in the sense that such colors when combined in preselected proportions can generate any color in the spectrum. While use of three primary colors is preferred, it will be understood that the present invention will function nearly as well with only two primary colors to generate a wide variety of colors in the spectrum. Likewise, while the different primary colors are arranged herein on sets of uniformly colored LEDS, it will be appreciated that the same effect may be achieved with single LEDs containing multiple color-emitting semiconductor dies. LED sets 121 , 140 and 160 each preferably contains a serial/parallel array of LEDs in the manner described by Okuno in U.S. Pat. No. 4,298,869, incorporated herein by reference. In the present embodiment, LED system 120 includes LED set 121 , which contains three parallel connected rows of nine red LEDs (not shown), as well as LED sets 140 and 160 , which each contain five parallel connected rows of five blue and green LEDS, respectively (not shown). It is understood by those in the art that, in general, each red LED drops the potential in the line by a lower amount than each blue or green LED, about two and one-tenth V, compared to four volts, respectively, which accounts for the different row lengths. This is because the number of LEDs in each row is determined by the amount of voltage drop desired between the anode end at the power supply voltage and the cathode end of the last LED in the row. Also, the parallel arrangement of rows is a fail-safe measure that ensures that the light module 100 will still function even if a single LED in a row fails, thus opening the electrical circuit in that row. The cathode ends of the three parallel rows of nine red LEDs in LED set 121 are then connected in common, and go to pin 128 on connector 110 . Likewise, the cathode ends of the five parallel rows of five blue LEDs in LED set 140 are connected in common, and go to pin 148 on connector 110 . The cathode ends of the five parallel rows of five green LEDs in LED set 160 are connected in common, and go to pin 168 on connector 110 . Finally, on light module 100 , each LED set in the LED system 120 is associated with a programming resistor that combines with other components, described below, to program the maximum current through each set of LEDS. Between pin 124 and 126 is resistor 122 , six and two-tenths ohms. Between pin 144 and 146 is resistor 142 , four and seven-tenths ohms. Between pin 164 and 166 is resistor 162 , four and seven-tenths ohms. Resistor 122 programs maximum current through red LED set 121 , resistor 142 programs maximum current through blue LED set 140 , and resistor 162 programs maximum current through green LED set 160 . The values these resistors should take are determined empirically, based on the desired maximum light intensity of each LED set. In the embodiment depicted in FIG. 3 , the resistances above program red, blue and green currents of seventy, fifty and fifty mA, respectively.

[0110] As shown in FIG. 6, a circuit 10 for a digitally controlled LED-based light includes an LED assembly 12 containing LED output channels 14 , which are controlled by the processor 16 . Data and power are fed to the circuit 10 via power and data input unit 18 . The address for the processor 16 is set by switch unit 20 containing switches which are connected to individual pins of pin set 21 of processor 16 . An oscillator 19 provides a clock signal for processor 16 via pins 9 and 10 of the same.

[0111] In an embodiment of the invention, data and power input unit 18 has four pins, including a power supply 1 , which may be a twenty-four volt LED power supply, a processor power supply 2 , which may be a five volt processor power supply, a data in line 3 and a ground pin 4 . The first power supply 1 provides power to LED channels 14 of LED assembly 12 . The second processor power supply 2 may be connected to power supply input 20 of processor 16 to provide operating power for the processor 16 and also may be connected to a pin 1 of the processor 16 to tie the reset high. A capacitor 24 , such as a one-tenth microfarad capacitor, may be connected between the processor power supply 2 and ground. The data line 3 may be connected to pin 18 of processor 16 and may be used to program and dynamically control the processor 16 . The ground may be connected to pins 8 and 19 of the processor 16 .

[0112] LED assembly 12 may be supplied with power from the LED power supply 1 and may contain a transistor-controlled LED channel 14 . The LED channel 14 may supply power to at least one LED. As shown in FIG. 1 , the LED assembly 12 may supply multiple LED channels 14 for different color LEDs (e.g., red, green and blue), with each LED channel 14 individually controlled by a transistor 26 . However, it is possible that more than one channel 14 could be controlled by a single transistor 26 .

[0113] As shown in FIG. 7 , LEDs 15 may be arrayed in series to receive signals through each of the LED channels 14 . In the embodiment depicted in FIG. 7, a series of LEDs of each different color (red, green and blue) is connected to an output LED channel 14 from the circuit 10 of FIG. 6 . LEDs 15 may also be arrayed to receive data according to a protocol such as the DMX-512 protocol, so that many individual LEDs 15 may be controlled through programming the processor 16 .

[0114] Referring again to FIG. 6 , gates of transistors 26 are controlled by processor 16 to thereby control operation of the LED channels 14 and the LEDs 15 . In the illustrated example, the output of the microprocessor appears on pins 12 , 13 and 14 of processor 16 , which are then connected to the gates of the LED channels 14 of the LEDs 15 . Additional pins of processor 16 could be used to control additional LEDs. Likewise, different pins of processor 16 could be used to control the illustrated LEDs 15 , provided that appropriate modifications were made to the instructions controlling operation of processor 16 .

[0115] A resistor 28 may be connected between transistor 26 and ground. In the illustrated example, resistor 28 associated with the red LED has a resistance value of sixty-two ohms, and the resistors associated with the green and blue LEDs each have a resistance of ninety ohms. A capacitor 29 may be connected between the first LED power supply 1 and ground. In the illustrated embodiment, this capacitor has a value of one-tenth of a microfarad.

[0116] Processor 16 may be connected to an oscillator 19 . One acceptable oscillator is a crystal tank circuit oscillator which provides a twenty megaHertz clock. This oscillator may be connected to pins 9 and 10 of processor 16 . It is also possible to use an alternative oscillator. Primary considerations associated with selection of an oscillator are consistency, operating speed and cost.

[0117] In an embodiment of the invention, processor 16 is a programmable integrated circuit, or PIC chip, such as a PIC 16C63 or PIC 16C66 manufactured by Microchip Technology, Inc. A complete description of the PIC 16C6X series PIC chip (which includes both the PIC 16C63 and PIC 16C66) is attached to the U.S. Provisional Patent Application filed on Dec. 17, 1997, entitled Digitally Controlled Light Emitting Diode Systems and Methods, to Mueller and Lys, and is incorporated by reference herein. Although the PIC 16C66 is currently the preferred microprocessor, any processor capable of controlling the LEDs 15 of LED assembly 12 may be used. Thus, for example, an application specific integrated circuit (ASIC) may be used instead of processor 16 . Likewise, other commercially available processors may also be used without departing from this invention.

[0118] In an embodiment of the invention depicted in FIG. 8, a total of eighteen LEDs 15 are placed in three series according to color, and the series are arranged to form a substantially circular array 37 . The processor 16 can be used to separately control the precise intensity of each color series of the LEDs 15 , so that any color combination, and thus any color, can be produced by the array 37 .

[0119] The responsiveness of LEDs to changing electrical signals permits computer control of the LEDs via control of the electrical impulses delivered to the LEDs. Thus, by connecting the LED to a power source via a circuit that is controlled by a processor, the user may precisely control the color and intensity of the LED. Due to the relatively instantaneous response of LEDs to changes in electrical impulses, the color and intensity state of an LED may be varied quite rapidly by changes in such impulses. By placing individual LEDs into arrays and controlling individual LEDs, very precise control of lighting conditions can be obtained through use of a microprocessor. The processor 16 may be controlled by conventional means, such as a computer program, to send the appropriate electrical signals to the appropriate LED at any given time. The control may be digital, so that precise control is possible. Thus, overall lighting conditions may be varied in a highly controlled manner.

[0120] With the electrical structure of an embodiment of light module 100 described, attention will now be given to the electrical structure of an example of a power module 200 in one embodiment of the invention, shown in FIG. 9 . FIGS. 10 and 11 show the power terminal side and electrical connector side of an embodiment of power module 200 . Like light module 100 , power module 200 may be self contained. Interconnection with a male pin set 110 is achieved through complementary female pin set 210 . Pin 280 connects with pin 180 for supplying power, delivered to pin 280 from supply 300 . Supply 300 is shown as a functional block for simplicity. In actuality, supply 300 can take numerous forms for generating a DC voltage. In the present embodiment, supply 300 provides twenty-four volts through a connection terminal (not shown), coupled to pin 280 through transient protection capacitors (not shown) of the general type. It will be appreciated that supply 300 may also supply a DC voltage after rectification and/or voltage transformation of an AC supply, as described more fully in U.S. Pat. No. 4,298,869.

[0121] Also connected to pin connector 210 are three current programming integrated circuits, ICR 220 , ICB 240 and ICG 260 . Each of these may be a three terminal adjustable regulator, such as part number LM317B, available from the National Semiconductor Corporation, Santa Clara, Calif. The teachings of the LM317 datasheet are incorporated herein by reference. Each regulator contains an input terminal, an output terminal and an adjustment terminal, labeled I, O, and A, respectively. The regulators function to maintain a constant maximum current into the input terminal and out of the output terminal. This maximum current is pre-programmed by setting a resistance between the output and the adjustment terminals. This is because the regulator will cause the voltage at the input terminal to settle to whatever value is needed to cause one and twenty-five hundredths volts to appear across the fixed current set resistor, thus causing constant current to flow. Since each functions identically, only ICR 220 will now be described. First, current enters the input terminal of ICR 220 from pin 228 . Pin 228 in the power module is coupled to pin 128 in the light module and receives current directly from the cathode end of the red LED system 121 . Since resistor 122 is ordinarily disposed between the output and adjustment terminals of ICR 220 through pins 224 / 124 and 226 / 126 , resistor 122 programs the amount of current regulated by ICR 220 . Eventually, the current output from the adjustment terminal of ICR 220 enters a Darlington driver. In this way, ICR 220 and associated resistor 122 program the maximum current through red LED system 120 . Similar results are achieved with ICB 240 and resistor 142 for blue LED set 140 , and with ICG 260 and resistor 162 for green LED set 160 .

[0122] The red, blue and green LED currents enter another integrated circuit, ICI 380 , at respective nodes 324 , 344 and 364 . ICI 380 may be a high current/voltage Darlington driver, such as part no. DS2003, available from the National Semiconductor Corporation, Santa Clara, Calif. ICI 380 may be used as a current sink, and may function to switch current between respective LED sets and ground 390 . As described in the DS2003 datasheet, incorporated herein by reference, ICI contains six sets of Darlington transistors with appropriate on-board biasing resistors. As shown, nodes 324 , 344 and 364 couple the current from the respective LED sets to three pairs of these Darlington transistors, in the well known manner to take advantage of the fact that the current rating of ICI 380 may be doubled by using pairs of Darlington transistors to sink respective currents. Each of the three on-board Darlington pairs is used in the following manner as a switch. The base of each Darlington pair is coupled to signal inputs 424 , 444 and 464 , respectively. Hence, input 424 is the signal input for switching current through node 324 , and thus the red LED set 121 . Input 444 is the signal input for switching current though node 344 , and thus the blue LED set 140 . Input 464 is the signal input for switching current through node 364 , and thus the green LED set 160 . Signal inputs 424 , 444 and 464 are coupled to respective signal outputs 434 , 454 and 474 on microcontroller IC 2 400 , as described below. In essence, when a high frequency square wave is incident on a respective signal input, ICI 380 switches current through a respective node with the identical frequency and duty cycle. Thus, in operation, the states of signal inputs 424 , 444 and 464 directly correlate with the opening and closing of the power circuit through respective LED sets 121 , 140 and 160 .

[0123] The structure and operation of microcontroller IC 2 400 in the embodiment of FIG. 9 will now be described. Microcontroller IC 2 400 is preferably a MICROCHIP brand PIC16C63, although almost any properly programmed microcontroller or microprocessor can perform the software functions described herein. The main function of microcontroller IC 2 400 is to convert numerical data received on serial Rx pin 520 into three independent high frequency square waves of uniform frequency but independent duty cycles on signal output pins 434 , 454 and 474 . The FIG. 9 representation of microcontroller IC 2 400 is partially stylized, in that persons of skill in the art will appreciate that certain of the twenty-eight standard pins have been omitted or combined for greatest clarity. Further detail as to a similar microcontroller is provided in connection with FIG. 12 for another embodiment of the invention.

[0124] Microcontroller IC 2 400 is powered through pin 450 , which is coupled to a five volt source of DC power 700 . Source 700 is preferably driven from supply 300 through a coupling (not shown) that includes a voltage regulator (not shown). An exemplary voltage regulator is the LM340 3-terminal positive regulator, available from the National Semiconductor Corporation, Santa Clara, Calif. The teachings of the LM340 datasheet are hereby incorporated by reference. Those of skill in the art will appreciate that most microcontrollers, and many other independently powered digital integrated circuits, are rated for no more than a five volt power source. The clock frequency of microcontroller IC 2 400 is set by crystal 480 , coupled through appropriate pins. Pin 490 is the microcontroller IC 2 400 ground reference.

[0125] Switch 600 is a twelve position dip switch that may be alterably and mechanically set to uniquely identify the microcontroller IC 2 400 . When individual ones of the twelve mechanical switches within dip switch 600 are closed, a path is generated from corresponding pins 650 on microcontroller IC 2 400 to ground 690 . Twelve switches create twenty-four possible settings, allowing any microcontroller IC 2 400 to take on one of four thousand ninety-six different IDs, or addresses. In the embodiment of FIG. 9 , only nine switches are actually used because the DMX-512 protocol is employed.

[0126] Once switch 600 is set, microcontroller IC 2 400 “knows” its unique address (“who am I”), and “listens” on serial line 520 for a data stream specifically addressed to it. A high speed network protocol, such as a DMX protocol, may be used to address network data to each individually addressed microcontroller IC 2 400 from a central network controller (not shown). The DMX protocol is described in a United States Theatre Technology, Inc. publication entitled “DMX512/1990 Digital Data Transmission Standard for Dimmers and Controllers,” incorporated herein by reference. Basically, in the network protocol used herein, a central controller (not shown) creates a stream of network data consisting of sequential data packets.

[0127] Each packet first contains a header, which is checked for conformance to the standard and discarded, followed by a stream of sequential characters representing data for sequentially addressed devices. For instance, if the data packet is intended for light number fifteen, then fourteen characters from the data stream will be discarded, and the device will save character number fifteen. If as in the preferred embodiment, more than one character is needed, then the address is considered to be a starting address, and more than one character is saved and utilized. Each character corresponds to a decimal number zero to two hundred fifty-five, linearly representing the desired intensity from Off to Full. (For simplicity, details of the data packets such as headers and stop bits are omitted from this description, and will be well appreciated by those of skill in the art.) This way, each of the three LED colors is assigned a discrete intensity value between zero and two hundred fifty-five. These respective intensity values are stored in respective registers within the memory of microcontroller IC 2 400 (not shown). Once the central controller exhausts all data packets, it starts over in a continuous refresh cycle. The refresh cycle is defined by the standard to be a minimum of one thousand one hundred ninety-six microseconds, and a maximum of one second.

[0128] Microcontroller IC 2 400 is programmed continually to “listen” for its data stream. When microcontroller IC 2 400 is “listening,” but before it detects a data packet intended for it, it is running a routine designed to create the square wave signal outputs on pins 434 , 454 and 474 . The values in the color registers determine the duty cycle of the square wave. Since each register can take on a value from zero to two hundred fifty five, these values create two hundred fifty six possible different duty cycles in a linear range from zero percent to one hundred percent. Since the square wave frequency is uniform and determined by the program running in the microcontroller IC 2 400 , these different discrete duty cycles represent variations in the width of the square wave pulses. This is known as pulse width modulation (PWM).

[0129] In one embodiment of the invention, the PWM interrupt routine is implemented using a simple counter, incrementing from zero to two hundred fifty-five in a cycle during each period of the square wave output on pins 434 , 454 and 474 . When the counter rolls over to zero, all three signals are set high. Once the counter equals the register value, signal output is changed to low. When microcontroller IC 2 400 receives new data, it freezes the counter, copies the new data to the working registers, compares the new register values with the current count and updates the output pins accordingly, and then restarts the counter exactly where it left off. Thus, intensity values may be updated in the middle of the PWM cycle. Freezing the counter and simultaneously updating the signal outputs has at least two advantages. First, it allows each lighting unit to quickly pulse/strobe as a strobe light does. Such strobing happens when the central controller sends network data having high intensity values alternately with network data having zero intensity values at a rapid rate. If one restarted the counter without first updating the signal outputs, then the human eye would be able to perceive the staggered deactivation of each individual color LED that is set at a different pulse width. This feature is not of concern in incandescent lights because of the integrating effect associated with the heating and cooling cycle of the illumination element. LEDS, unlike incandescent elements, activate and deactivate essentially instantaneously in the present application. The second advantage is that one can “dim” the LEDs without the flickering that would otherwise occur if the counter were reset to zero. The central controller can send a continuous dimming signal when it creates a sequence of intensity values representing a uniform and proportional decrease in light intensity for each color LED. If one did not update the output signals before restarting the counter, there is a possibility that a single color LED will go through nearly two cycles without experiencing the zero current state of its duty cycle. For instance, assume the red register is set at 4 and the counter is set at 3 when it is frozen. Here, the counter is frozen just before the “off part” of the PWM cycle is to occur for the red LEDS. Now assume that the network data changes the value in the red register from four to two and the counter is restarted without deactivating the output signal. Even though the counter is greater than the intensity value in the red register, the output state is still “on”, meaning that maximum current is still flowing through the red LEDS. Meanwhile, the blue and green LEDs will probably turn off at their appropriate times in the PWM cycle. This would be perceived by the human eye as a red flicker in the course of dimming the color intensities. Freezing the counter and updating the output for the rest of the PWM cycle overcomes these disadvantages, ensuring the flicker does not occur.

[0130] The microprocessors that provide the digital control functions of the LEDs of the present invention may be responsive to any electrical signal; that is, external signals may be used to direct the microprocessors to control the LEDs in a desired manner. A computer program may control such signals, so that a programmed response to given input signals is possible. Thus, signals may be generated that turn individual LEDs on and off, that vary the color of individual LEDs throughout the color spectrum, that strobe or flash LEDs at predetermined intervals that are controllable to very short time intervals, and that vary the intensity of light from a single LED or collection of LEDs. A variety of signal-generating devices may be used in accordance with the present invention to provide significant benefits to the user. Input signals can range from simple on-off or intensity signals, such as that from a light switch or dial, or from a remote control, to signals from detectors, such as detectors of ambient temperature or light. The precise digital control of arrayed LEDs in response to a wide range of external signals permits applications in a number of technological fields in accordance with the present invention.

[0131] The network interface for microcontroller IC 2 400 will now be described. Jacks 800 and 900 are standard RJ-45 network jacks. Jack 800 is used as an input jack, and is shown for simplicity as having only three inputs: signal inputs 860 , 870 and ground 850 . Network data enters jack 800 and passes through signal inputs 860 and 870 . These signal inputs are then coupled to IC 3 500 , which is an RS-485/RS-422 differential bus repeater of the standard type, preferably a DS96177 from the National Semiconductor Corporation, Santa Clara, Calif. The teachings of the DS96177 datasheet are hereby incorporated by reference. The signal inputs 860 , 870 enter IC 3 500 at pins 560 , 570 . The data signal is passed through from pin 510 to pin 520 on microcontroller IC 2 400 . The same data signal is then returned from pin 540 on IC 2 400 to pin 530 on IC 3 500 . Jack 900 is used as an output jack and is shown for simplicity as having only five outputs: signal outputs 960 , 970 , 980 , 990 and ground 950 . Outputs 960 and 970 are split directly from input lines 860 and 870 , respectively. Outputs 980 and 990 come directly from IC 3 500 pins 580 and 590 , respectively. It will be appreciated that the foregoing assembly enables two network nodes to be connected for receiving the network data. Thus, a network may be constructed as a daisy chain, if only single nodes are strung together, or as a tree, if two or more nodes are attached to the output of each single node.

[0132] From the foregoing description, one can see that an addressable network of LED illumination or display units can be constructed from a collection of power modules each connected to a respective light module. As long as at least two primary color LEDs are used, any illumination or display color may be generated simply by preselecting the light intensity that each color LED emits. Further, each color LED can emit light at any of 255 different intensities, depending on the duty cycle of PWM square wave, with a full intensity generated by passing maximum current through the LED. Further still, the maximum intensity can be conveniently programmed simply by adjusting the ceiling for the maximum allowable current using programming resistances for the current regulators residing on the light module. Light modules of different maximum current ratings may thereby be conveniently interchanged.

[0133] In an alternative embodiment of the invention, a special power supply module 38 is provided, as depicted in FIG. 12 . The power supply module 38 may be disposed on any platform of the light module 100 , such as, for example, the platform of the embodiment depicted in FIGS. 4 and 5 . The output of the power supply module 38 supplies power to a power and data input, such as the power and data input 18 of the circuit 10 of FIG. 6 . The power supply module 38 is capable of taking a voltage or current input in a variety of forms, including an intermittent input, and supplying a steady, clean source of power to the circuit 10 . In the embodiment depicted in FIG. 12 , the power supply module includes inputs 40 , which may be incoming electrical signals that would typically be of alternating current type. Incoming signals are then converted by a rectifying element 42 , which in an embodiment of the invention is a bridge rectifier consisting of four diodes 44 . The rectifying element 42 rectifies the alternating current signal into a clean direct current signal. The power supply module 38 may further include a storage element 48 , which may include one or more capacitors 50 . The storage element stores power that is supplied by the rectifying element 42 , so that the power supply module 38 can supply power to the input 18 of the circuit 10 of FIG. 6 , even if power to the input 40 of the power supply module 38 is intermittent. In the illustrated example, one of the capacitors is an electrolytic capacitor with a value of three hundred thirty microfarads.

[0134] The power supply module 38 may further include a boost converter 52 . The boost converter takes a low voltage direct current and boosts and cleans it to provide a higher voltage to the DC power input 18 of the circuit 10 of FIG. 6 . The boost converter 52 may include an inductor 54 , a controller 58 , one or more capacitors 60 , one or more resistors 62 , and one or more diodes 64 . The resistors limit the data voltage excursions in the signal to the processor of the circuit 10 . The controller 58 may be a conventional controller suitable for boost conversion, such as the LTC1372 controller provided by Linear Technology Corporation. The teachings of the LTC1372 data sheet are incorporated by reference herein.

[0135] In the illustrated embodiment, the boost converter 52 is capable of taking power at approximately ten volts and converting it to a clean power at twenty-four volts. The twenty-four volt power can be used to power the circuit 10 and the LEDs 15 of FIG. 6 .

[0136] In certain embodiments of the invention, power and data are supplied to the circuit 10 and the LEDs 15 by conventional means, such as a conventional electrical wire or wires for power and a separate wire, such as the RS-485 wire, for data, as in most applications of the DMX-512 protocol. For example, in the embodiment of FIG. 4 and FIG. 5, a separate data wire may provide data to control the LEDs 15 , if the platform 30 is inserted into a conventional halogen fixture 34 that has only electrical power.

[0137] In another embodiment, electrical power and serial data are simultaneously supplied to the device, which may be a lighting device such as the LED-based lighting device of FIG. 1 or may be any other device that requires both electrical power and data. Electrical power and data may be supplied to multiple lighting devices on a single pair of wires. In particular, in this embodiment of the invention, power is delivered to the device (and, where applicable, through the power supply module 38 ) along a two wire data bus such as the type normally used for lighting in applications where high power is required, such as halogen lamps.

[0138] In an embodiment of the invention, the power supply module 38 recovers power from data lines. In order to permit power recovery from data lines, a power data multiplexer 60 is provided, which amplifies an incoming data stream to produce logical data levels, with one or more of the logical states having sufficient voltage or current that power can be recovered during that logical state. Referring to FIG. 13 , in an embodiment of the invention, a data input 64 is provided, which may be a line driver or other input for providing data. In embodiment of the invention, the data is DMX-512 protocol data for control of lighting, such as LEDs. It should be understood that the power data multiplexer 60 could manipulate data according to other protocols and for control of other devices.

[0139] The power data multiplexer 60 may include a data input element 68 and a data output element 70 . The data output element 70 may include an output element 72 that supplies combined power and data to a device, such as the power supply module 38 of FIG. 12 , or the input 18 of the circuit 10 of FIG. 6 . The data input element 68 may include a receiver 74 , which may be an RS-485 receiver for receiving DMX-512 data, or any other conventional receiver for receiving data according to a protocol. The data input element 68 may further include a power supply 78 with a voltage regulator 80 , for providing regulated power to the receiver 74 and the data output element 70 . The data input element 68 supplies a data signal to the data output element 70 . In the illustrated embodiment of FIG. 12, a TTL data signal is supplied. The data output element 70 amplifies the data signal and determines the relative voltage direction of the output. In the illustrated embodiment, a chip 82 consists of a high speed PWM stepper motor driver chip that amplifies the data signal to a positive signal of twenty four volts to reflect a logical one and to negative signal of twenty four volts to reflect a logical zero. It should be understood that different voltages could be used to reflect logical ones and zeros. For example, zero volts could represent logical zero, with a particular positive or negative voltage representing a logical one.

[0140] In this embodiment, the voltage is sufficient to supply power while maintaining the logical data values of the data stream. The chip 82 may be any conventional chip capable of taking an input signal and amplifying it in a selected direction to a larger voltage. It should be understood that any circuit for amplifying data while maintaining the logical value of the data stream may be used for the power data multiplexer 60 .

[0141] The embodiments of FIGS. 12 and 13 should be understood to encompass any devices for converting a data signal transmitted according to a data protocol, in which certain data are represented by nonzero signals in the protocol, into power that supplies an electrical device. The device may be a light module 100 , such as that depicted in FIG. 1 .

[0142] In an embodiment of the invention, the data supplied to the power data multiplexer 60 is data according to the USITT DMX-512 protocol, in which a constant stream of data is transmitted from a console, such as a theatrical console, to all devices on the DMX-512 network. DMX-512 formats are enforced upon the data. Because of this one can be assured that the power data multiplexer 60 , either in the embodiment depicted in FIG. 13 , or in another embodiment, can amplify the DMX-512 signal from the standard signal voltage and/or electrical current levels to higher voltages, and usually higher electrical currents.

[0143] The resulting higher power signal from the power data multiplexer 60 can be converted back into separated power by the power supply module 38 , or by another circuit capable of providing rectification with a diode and filtering with a capacitor for the power.

[0144] The data stream from the power data multiplexor 60 can be recovered by simple resistive division, which will recover a standard data voltage level signal to be fed to the input 18 . Resistive division can be accomplished by the resistors 84 of FIG. 12 .

[0145] The power data multiplexer 62 , when combined with the power supply module 38 and the array 37 mounted on a modular platform 30 , permits the installation of LED-based, digitally controlled lighting using already existing wires and fixtures. As the system permits the device to obtain power and data from a single pair of wires, no separate data or power wires are required. The power data multiplexor 60 can be installed along a conventional data wire, and the power supply module 38 can be installed on the platform 30 . Thus, with a simple addition of the power data multiplexor 60 and the insertion of the modular platform 30 into a conventional halogen fixture, the user can have LED based, digitally controlled lights by supplying DMX-512 data to the power data multiplexor 60 .

[0146] It should be understood that the power supply module 38 can be supplied with standard twelve volt alternating current in a non-modified manner. That is, the power supply module can supply the array 37 from alternating current present in conventional fixtures, such as MR-16 fixtures. If digital control is desired, then a separate data wire can be supplied, if desired.

[0147] Another embodiment of a power data multiplexor 60 is depicted in FIG. 14 . In this embodiment, a power supply of between twelve and twenty-four volts is used, connected to input terminals 899 .

[0148] The voltage at 803 is eight volts greater than the supply voltage. The voltage at 805 is about negative eight volts. The voltage at 801 is five volts. The power data multiplexor 60 may include decoupling capacitors 807 and 809 for the input power supply. A voltage regulator 811 creates a clean, five volt supply, decoupled by capacitor 813 . A voltage regulator 815 , which may be an LM317 voltage regulator available from National Semiconductor, forms an eighteen volt voltage regulator with resistors 817 and 819 , decoupled by capacitors 821 and 823 . The teachings of the LM317 data sheet are incorporated by reference herein. This feeds an adjustable step down regulator 823 , which may be an LT1375 step down regulator available from Linear Technology of Milpitas Calif., operated in the voltage inverting configuration. The teachings of the LT1375 data sheet are incorporated by reference herein. The resistances of resistors 817 and 819 have been selected create negative eight volts, and a diode 844 is a higher voltage version than that indicated in the data sheet, inductor 846 is may be any conventional inductor, for example, one with a value of one hundred uH to allow a smaller and cheaper capacitor to be used for the capacitor 848 , supply has been further bypassed with capacitor 852 . Diode 854 may be a plastic packaged version 1N914, and frequency compensating capacitor 856 sized appropriately for changes in other components according to data sheet formulas. The circuit generates negative eight volts at 805 .

[0149] Also included may be a step up voltage regulator 825 , which may be an LT1372 voltage regulator available from Linear Technology of Milpitas, Calif. The teachings of the LT1372 data sheet are incorporated by reference herein. The step up voltage regulator may be of a standard design. Diode 862 may be a diode with higher voltage than that taught by the data sheet. Inductor 864