Abstract: An invisible, light-transmissive display system with a light resistant material is provided. Substantially invisible, tapered, light-transmissive holes are penetrated in a light-transmissive pattern through at least a portion of the light resistant material using a laser beam having a focal width less than the smallest diameter of the tapered holes.

Abstract: An illumination system (10) comprises: —a light source (11); —a controller (12) controlling the power output of the light source; —a light sensor (16) wirelessly communicating with the controller. In a normal mode, the controller controls the light source such that the light level remains substantially constant. In a change mode, the controller controls the light source such that the light level is gradually changed with a predetermined change rate (R) such as to decrease a deviation from a target level (LT). The controller switches from its normalmode to its change mode on the basis of input signals received from the light sensor. The light sensor measures a light level, and decides whether or notto communicate a signalto the controller. The light sensor refrains from transmitting a signal when receiving the signal will not cause the controller to change its control behaviour.

Abstract: The invention provides an illumination arrangement (1) for illuminating horticultural growths (100) with for instance LEDs as a light source. These LEDs are placed in a lighting unit (10). The lighting unit may especially have the ability to direct substantially all light from the light source (here the LEDs) to the horticultural growths (in the greenhouse). Additionally, a horticultural growth-recognition system (50) can be implemented in the illumination arrangement, so that the system can adapt for instance its beam (11) to the location of the horticultural growth(s) (in the case of growth or moving of plants, etc).

Abstract: Systems and methods for transmitting and processing interrupts by embedding interrupt information into a serial data stream are disclosed. An event is detected and converted into an interrupt signal. The interrupt signal is converted into a special interrupt character or symbol sequence. The special interrupt character or symbol sequence is embedded into a serial data stream at the next available character or symbol boundary and transmitted to a receiving controller. The receiving controller strips the special interrupt character or symbol sequence from the serial data stream and raises a corresponding interrupt. The receiving controller processes the interrupt by interrupting normal processing to run an interrupt subroutine. Once the receiver has detected and raised an interrupt, it can return an acknowledgement character or symbol sequence by the same mechanism.

Abstract: A camouflage panel arranged to be attachable to an outer area of a submarine is disclosed. The panel comprises a light emitter operable such that light is emitted from a surface of the panel. The intensity and colour of the emitted light being controllable in response to a control signal received from a sensor arranged to sense the intensity and colour of light in the region of the submarine. Apparatus comprising a number of such panels is also disclosed.

Abstract: In illustrative implementations of this invention, a lighting system comprises a plurality of LEDs, fluorescent lights, incandescent lights, a processor, a sensor node and a human-computer interface. The sensor is adapted to be moved by a user and placed in the location that a user wants to illumine. The LED lights are adapted to emit pulse-width modulated (PWM) light, controlled by signals from the processor. The lighting system is adapted to optimize parameters (such as efficacy or color rendering index) selected by the user, subject to certain constraints (such as desired illuminance or color temperature). According to principles of this invention, if a sensor is moved, attenuation may be measured and the inverse square law may be used to determine how constraints in an optimization algorithm need to be updated.

Abstract: An actuator rod position indication device is described, where a unit having a separate enclosing housing on one surface of said housing has mounted a magnetic field sensor, such that a magnet provided on an actuator rod's free end will be moved substantially linearly closer to and further from said sensor during operation of the actuator, where the sensor detects the magnetic field strength between the magnet on the actuator rod and the sensor and uses this information as input in a processor, comprising a storage, in which storage pre-defined activation values are stored, such that when the input corresponds to one of the stored values, an output specific to that value is generated.

Abstract: An automated method of sampling an electrical condition of each of a plurality channels, the method comprising: driving each of the plurality of channels with a modulated signal; providing a settable flag associated with each of the plurality of channels; selecting one of the plurality of channels; identifying if the settable flag associated with the selected one of the plurality of channels is set; and in the event that the settable flag associated with the selected one of the plurality of channels is not set, and a function of the modulated signal of the selected one of the plurality of channels is active and stable: sampling an electrical condition of the selected one of the plurality of channels; and setting the provided settable flag associated with the selected one of the plurality of channels.

Abstract: A plurality of LEDs arranged in groups, each group comprising at least one LED, a control circuit for driving the LEDs, the control circuit comprising a sensing device for sensing an operative parameter of the LEDs. The control circuit is arranged to: a) operate at least one group of the LEDs: b) sense by the sensing device a value of the operative parameter of the at least one group; c) repeat a) and b) for at least a different one of the groups; d) assign to each of the groups of LEDs a value of the operative parameter from the sensed operative parameter values; and e) control the driving of the groups of LEDs from the assigned operative parameter values.

Abstract: A system and method involving lighting fixtures, a control network, a controller and other devices such as light sensors, input devices and network adapters for coordinating precise brightness and color schedules among the lighting fixtures while maintaining a high color reliability including provisions for managing a plurality of lighting fixtures. The lighting fixtures contain lighting elements selected such that when controlled properly, operating along a daytime locus, the resultant light output closely resembles sunlight on a cloudless day in spectral characteristics, and wherein the total flux of blue light can be adjusted from a relative level of 1-100% the maximum blue flux of the lighting fixture by controlling individual lighting elements.

Abstract: Sensor devices (1) are provided with trigger signal generators (2) for repeatedly generating trigger signals and light detectors (12) for detecting light parameters such as intensities and colors and color temperatures and patterns and fluctuations of light (43) at a location and transmitters (9) for, in response to trigger signals, transmitting control signals based on detections to control devices (20) for controlling light sources (40) to influence the light (43) at the location. The sensor devices (1) may further comprise theme code generators (3), location code generators (4), processors (5), scanners (10), and position detectors (6).

Abstract: The present disclosure relates to a duty cycle adjusting circuit of a lighting system and method thereof for sensing light of a first color and a second color emitted by a light emitting device of the first color and a light emitting device of the second color to generate corresponding intensity values. Then a first pulse width correcting value and a second pulse width correcting value can be calculated for adjusting a first duty cycle and a second duty cycle of a driving current to adjust the illuminating intensity of the light emitting devices of the first and the second colors. Through these adjusting steps, the light of the first and the second colors is within a predetermined range of color temperature. Therefore, light source for stable light in color temperature is provided.

Abstract: An electrically powered flame simulator comprises at least two light sources, an integrated circuit electrically connected to the light sources for intermittently illuminating at least one of the light sources independently of other light sources such that the light sources together provide the effect of a flickering movement, and a power source for providing power to the integrated circuit. The flame simulator may be mounted in a decorative or ornamental device such as a candle or fire log, or used on decorative clothing, or may be part of a hazzard or warning system. One or more solid state light sources may also be used.

Abstract: A light source having first and second LEDs and a phosphor layer that converts light generated by the first LED is disclosed. The first LED emits light at a first wavelength. The layer of phosphor is illuminated by the first LED, the phosphor being excited by light of the first wavelength to convert light of the first wavelength to a band of wavelengths having wavelengths between the first wavelength and a second wavelength. The second LED emits light at a third wavelength that is greater than the first wavelength. The phosphor is not substantially excited by light of the third wavelength. The combined light from the phosphor, and first and second LEDs is perceived as being white by a human observer.

Abstract: A solid state lighting apparatus according to some embodiments includes a circuit including a plurality of light emitting devices, and a configurable shunt configured to bypass at least some current around at least one light emitting device of the plurality of light emitting devices. The configurable shunt may include, for example, a tunable resistor, a fuse, a switch, a thermistor, and/or a variable resistor.

Abstract: A lighting device at least has: a plurality of light emitting elements that emit light by a forward direction current; a direct-current power supply; a first wiring and a second wiring for supplying electrical power to the plurality of light emitting elements from the direct-current power supply; and a switch for switching the polarity of the electrical power to be supplied to the first wiring and the second wiring; in which the plurality of light emitting elements include forward direction connection in which the forward direction current flows when the electrical power having a positive polarity is applied to the first wiring and reverse direction connection in which the forward direction current flows when the electrical power having a positive polarity is applied to the second wiring and being connected between the first wiring and the second wiring.

Abstract: A lighting system is presented that includes a replaceable illumination module removably coupled to a base module. The replaceable illumination module includes one or more solid state lighting elements on a printed circuit board electrically and thermally connected to the base module. The base module may include a heat sink, where the heat sink is in thermal contact with the replaceable illumination module, and dissipates heat generated by the one or more solid state lighting elements during operation of the lighting system. The replaceable illumination module may also include one or more beam conditioning elements for generating a specified beam. The lighting system may be connected to an automated control network and may be automatically controlled thereby, or may be used to control some other system. The heat sink may be generated via a dynamically controllable extrusion die.

Abstract: An illumination system including a master control unit, a device unit, a driving circuit unit, and an illumination unit is provided. The master control unit receives an input signal and outputs a control signal by performing a program operation processing to the input signal. The device unit analyzes the control signal so as to obtain a color temperature setting value and a brightness setting value, and generates two output signals according to the brightness setting value and two color temperature adjusting signals determined by the color temperature setting value. The illumination unit has at least two lamps with different color temperatures. The driving circuit unit receives and converts the two output signals so as to proportionally output two driving signals to respectively drive the two lamps. One of the two output signals is enabled after the other of the two output signals is disabled for a predetermined time.

Abstract: Proposed is an illumination system (100) comprising a plurality of light sources (10) provided with encoders (20) arranged to enable light emitted from the light sources to comprise light source identification codes. In order to enable light effect commissioning, i.e. correlating the light sources (10) with their illumination footprints (11), the system further comprises a camera (40) arranged to register images of illumination spots (11), and a signal processor (111) arranged to derive the light source identification codes from registered images. Arranging the encoders (20) to modulate the light emitted at a frequency above a predefined high level to comprise fast codes (12) and at a frequency below a predefined low level to comprise slow codes (13), beneficially allows for the use of simple low cost camera systems.

Abstract: An illumination device includes: a light emitting element to be a light source; a light amount detecting means for detecting the amount of light emitted by the light emitting element; a light emitting element drive means for controlling drive current supplied to the light emitting element so that the difference between the light mount detected by the light amount detecting means and a light amount target value becomes small; a junction temperature detecting means for calculating junction temperature of the light emitting element; and a setting means for setting the light amount target value in accordance with the junction temperature detected by the junction temperature detecting means.

Abstract: Color matching and coordinated illumination is achieved using RGB LEDs and vector calibration.

Abstract: A system and method for operating an outdoor lighting feature is provided, the outdoor lighting feature including a bollard, a solar panel disposed within a recess on the top of the bollard, a battery disposed within the bollard, the battery being electrically coupled to the solar panel and configured to receive and store energy from the solar panel, and a light source oriented to direct a light beam to a region external to the bollard, the light source being configured to draw an electric load from the battery. The system detects a change in an ambient light level, starts a timer and places a light source in a high-on state in response to the change in the ambient light level, monitors the timer, places the light source in a low-on state upon measuring a first predefined amount of lapsed time on the timer, and places the light source in an off state upon measuring a second predefined amount of lapsed time on the timer.

Abstract: The present invention provides an optical system having an array of light emitting semiconductor devices to performing an operation that have multiple characteristics associated with performing the operation. The array includes at least one detector located within the array to selectively monitor multiple characteristics of the light emitting semiconductor devices and is configured to generate a signal corresponding to the selected characteristic. A controller is configured to control the light emitting semiconductor devices in response to the signal from the at least one detector. At least one of the multiple characteristics may be concentrated at an area of the array and the at least one detector may be located within the array at the area of the array to selectively monitor characteristic that is concentrated at the area of the array.

Abstract: An imaging device (300), a lighting control system (400) including the imaging device (300), and a method for aligning with a reference image lighting of a site (220) illuminated by least one light source (240) are provided. The imaging device (300) and/or the lighting control system (400) include at least one processor (410) configured to control the imaging device (300) and the light source (240). The imaging device (300) has an array of reflectors (320) including selectable reflectors; a lens configured to receive image rays (330) for forming an image including pixels and provide the image rays (330) to the array of reflectors (320) for reflection as reflected rays (355); and a detector (310) configured to receive the reflected rays (355) and detect characteristics of each pixel of the image for form a resolved image. The processor (410) is further configured to sequentially select each reflector (350) of the array of reflectors (320) for reflecting the reflected rays (355) towards the detector (310).

Abstract: Controlling an arrangement of semiconductors of which different semiconductors emit light of different distinct colors is disclosed, whereby a feed forward control part, which is dependent on a junction temperature of semiconductors for each color, is operated with first intervals and is adjusted dependent on measure light output for each color with much longer second intervals.

Abstract: A light emitting device with compensation capability is disclosed herein which includes a plurality of light emitting diodes, when a light emitting diode is out of order, the remaining of the light emitting diodes can still working properly; a status detecting unit; a power controlling unit; a processing unit to provide the control signals to the power controlling unit in order to dynamically provide the power to the light emitting diodes. By utilizing the LED device with light compensation capability, it can provide the stable power compensate.

Abstract: An LED light engine system that incorporates light emitting diodes (LEDs) with one or more distinct colors, including broad band white light obtained from phosphors or a combination of LED die colors and LED die coated phosphors. The LED die or die arrays are mounted to a high thermal conductivity circuit board comprising COB technology which can include both the LED die and electronic drive components resulting in a compact and reliable design with improved thermal and optical performance. High efficiency non-imaging collection optics are coupled to the LEDs to efficiently capture substantially all of the light which they emit and reformat it as an output with substantially the same éntendue as that of the LED to provide high brightness sources. Feedback from the output back to a photosensor on the circuit board is provided to assure that the output of the collection optic remains constant.

Abstract: This invention relates to a color controlled light source comprising a plurality of colored light elements, and a plurality of (filtered) photo detectors, having different spectral characteristics covering all or most of the total spectrum of the light elements. The (filtered) photo detectors detect the light output of the light source, and generate corresponding detection signals. The light source further has a color control unit for generating driving signals to the light elements on the basis of the detection signals and a predetermined target color point of the light output of the light source, and a modulator for individual signature modulation of the driving signal to each one of said light elements. A corresponding demodulator is provided for demodulation of the detection signals and extraction, from each detection signal, of actual values of the light outputs of the light elements.

Abstract: In a circuit arrangement for controlling light emitting diodes (LEDs), which are combined in an indicating table, including a voltage supply, at least one driver which is connected to the voltage supply and has current outputs by way of which current can be supplied to the LEDs as well as at least one control input via which the current being supplied to the LEDs is controllable, a control element is provided by which the number of the LEDs to which current has to be supplied at the same time can be determined and a signal indicative of the number determined can be supplied to the control input of the driver for assisting in controlling the power supply to the LEDs.

Abstract: A lighting control system for controlling a luminaire includes detection module and a control unit. The detection module is configured to detect traffic flow of a road and ambient light along the road. The control unit coupled with the detection module is configured to receive a detection result of the detection module and generate a control signal according to the detection result and a preset data stored therein for controlling illumination of the luminaire.

Abstract: A lighting fixture for deterring predation has a case containing a battery and one or more sources of illumination. A controller acts to cause intermittent flashing of the sources of illumination because the apparent motion deters predators. The case may have a bracket adapted for attachment to a post.

Abstract: The present invention relates to colour generation in an indoor or outdoor lighting device, and more particularly to a control method which provides spatially consistent colour control of a lighting device designed for use in, e.g., spatially extended premises or environments containing obstacles, and thus including multiple light sensors to allow efficient control. Colour consistency is achieved by an arrangement where light of one or more of the light sources impinges on more than one light sensor. If constructional detector features, such as filter characteristics, coincide, then these sensors should in principle, after the appropriate processing, report identical colour points of the light source under consideration. Indeed, colour is a path-independent property of light, and this is the basis for a mutual calibration scheme of the detectors according to the invention.

Abstract: The invention relates to an illumination system (100), a projection device, and a color wheel (20, 22, 24). The illumination system comprises a light source comprising a first light-emitting unit (50) and a second light-emitting unit each emitting light towards a light output window (110). The illumination system comprises the color wheel comprising a plurality of color segments (R, G, B), a boundary between two adjacent color segment being a spoke (40). The first light-emitting unit, the second light-emitting unit and the spoke are configured for preventing the spoke when transiting the optical path (80) between the light source and the light output window to simultaneously transit a first optical path between the first light-emitting unit and the light output window and a second optical path between the second light-emitting unit and the light output window.

Abstract: This invention relates to a color controlled light source comprising a plurality of colored light elements; a detector for detecting the light output of the light source and generating a detection signal; and a color control unit for generating driving signals to said light elements on the basis of said detection signal and a predetermined target color point of the light output of the light source. In order to enable detection of contributions from individual light elements to the light output of the light source, the light source further comprises a modulator for individual signature modulation of the driving signal to each one of said light elements; and a corresponding demodulator for demodulation of said detection signal and generation of actual, i.e. measured, values of the output of the individual light elements. The color control unit determines nominal values of the light output of each light element for obtaining said target color point, and compares the actual values with the nominal values.

Abstract: Certain people may at times find that life events cause absences from their residence. Due to the configuration of a residence entrance there are times of darkness when there is low or no ambient light to illuminate the entrance door hardware. Some people would not leave their porch light on for several hours. Some people may be uncomfortable with leaving the standard porch light on during their absence to avoid the expense of the utility power used by the lighting. A situation for the need to illuminate the hardware may include the unexpected prolonged time of being away from home. The present invention is a sustainable option to illuminate the storm door and exterior entrance door of a residence. This invention provides illumination of the doors hardware on demand.

Abstract: The present invention relates to a solid-state based light source, a corresponding circuitry and a method of emitting light, including one or more light source elements for generating light, a first sensor for receiving light emitted by the light source elements and ambient light and for generating a first sensor signal (S1) representing the received light, a second sensor for only receiving ambient light and for generating a second sensor signal (S2) representing the received ambient light. Moreover, the solid-state based light source comprises a control unit for receiving the first and the second sensor signals (S1, S2) and for generating control signals (Sc) for controlling the light source elements, based on the difference between the first and the second sensor signals (S1, S2), to compensate for the influence of the ambient light.

Abstract: An optoelectronic shutter, a method of operating the same, and an optical apparatus including the optoelectronic shutter are provided. The optoelectronic shutter includes a phototransistor which generates an output signal from incident input light and a light emitting diode serially connected to the phototransistor. The light emitting diode outputs output light according to the output signal, and the output signal is gain-modulated according to a modulation of a current gain of the phototransistor.

Abstract: The invention relates to a device and a method for controlling the light emission (1) of at least three light sources (21, 22, 23), wherein the light emitted by the light sources (21, 22, 23) is detected in a sequence of measuring periods during a calibration phase, and calculated on the basis of the information on the brightness of each individual light source (21, 22, 23) obtained during the measuring periods. In at least one of the measuring periods, the detected light comes from a plurality of the light sources (21, 22, 22).

Abstract: A lighting system (1) and its applications are described that are suitable especially in the realm of lighting systems (1) with high power light emitting diodes (LEDs). The lighting system (1) comprises a control circuit (3) with a memory device (4) and a refresh circuit (10), and the refresh circuit (10) is adapted to prevent data loss of the memory device (4) due to the reduction of the retention time of the memory device (4) caused by the high operation temperature of the LEDs.

Abstract: An illumination system correlates solar time to a clock and controls lighting or illumination based on time. The illumination system may turn ON light source(s) at a first level at a turn ON time, correlated to be around or at dusk, and turn OFF light source(s) at a turn OFF time, correlated to be around or at dawn. The illumination system may reduce a level of light output, and hence power consumption, at a time after turning ON a light source, and increases the level of light output at a time prior to turning OFF the light source. Turn ON, turn OFF, decrease and increase times may be determined based on recent levels of light or illumination in the environment, for example via average or median levels over a number of previous daily cycles. Filtering may eliminate aberrant events.

Abstract: An illumination system reduces a level of light output, and hence power consumption, at a time after turning ON a light source, and increases the level of light output at a time prior to turning OFF the light source. A control subsystem can determine when to increase the level of light based on a predicted time when the light source will be turned OFF. The control subsystem may determine an average or median length of time that the light source has been turned on for a number of recent daily cycles. A control subsystem may be an integral part of a luminaire or may be a retrofit.

Abstract: System and method are provided where a plurality of luminaires, control switches, occupancy detectors, and photocells are connected to a central control module including a user interface which is used for setting up, testing, commissioning and maintaining the system; a memory card interface and associated memory card which can be used to load and save configuration data, update firmware, and log system operation. Lighting system can be set up and tested and then the configuration saved in a portable memory, such as on a memory card which can be transferred to another system where it is read to facilitate faster and easier configuring of the other system to parallel, or to be exactly like, the original system. Data stored on a portable memory can be automatically recognized to perform appropriate actions such as, for example: update configuration, or update firmware.

Abstract: Greenhouse system may comprise an illumination, a sensor, and a controller. The illumination and controller are arranged to vary the intensity and the spectral distribution of the light emitted by the illumination. The emitted light may be pulsed light, the pulse characteristics being variable by the controller in dependency of the output of the sensor. The controller are arranged to interpret the relevant variables measured by the sensor and to assess the actual and/or expected growth of the relevant plants, and to control the intensity and/or the spectral distribution of the light emitted by the illumination. Some sensors may be provided for measuring the intensity and/or spectral distribution of the actual light in the greenhouse, other sensors for measuring plant dimensions of the relevant plants or plant groups. The illumination may comprise a heat collection which can be connected to heating or air conditioning inside or outside the greenhouse.

Abstract: A circuit for operating a plurality of electrical devices at a plurality of varying power levels includes a plurality of motion sensor circuits for detecting motion relative thereto and having an a plurality of outputs conditioned upon motion detection. Additionally, a photocell sensor circuit for detecting a low ambient illumination level has an output command conditioned upon the detection of a predetermined illumination level that is electrically coupled to the control circuit having a plurality of inputs.

Abstract: The invention relates to the automatic rendering of a lighting scene with a lighting system, particularly the control of the rendering. A basic idea of the invention is to perform rendering of a lighting scene by decomposing a lighting atmosphere to be rendered in elementary light effects, to classify the elementary light effects, and to coordinate the realisation of the classified light effects with the lighting system. An 5 embodiment of the invention provides a light control system (10) for automatically rendering a lighting atmosphere with a lighting system, wherein the light control system (10) is adapted for decomposing the lighting atmosphere to be rendered in elementary light-effects (14; S10), classifying the elementary light effects into sets of light effects (16; S12), and coordinating the realisation of the sets of light effects with the lighting 10 system (18; S14-S26).

Abstract: Lighting systems for providing supplemental light to plants to facilitate plant growth and/or to provide supplemental lighting in situations where sunlight is insufficient. Lighting systems may use LED technology to deliver specific wavelengths of light to maximize utilization of the supplemental light for photosynthesis. By delivering light having one or more specific wavelengths, it is possible to use a light that consumes relatively little power (e.g., about 10 watts or less) while providing sufficient supplemental light to facilitate healthy plant growth. Lighting systems may include a light-sensor to facilitate control of the amount of light provided. For example, a light-sensor may be used to automatically adjust the amount (e.g., intensity or duration) of light provided when the amount of ambient light available to the plant dips below a predetermined level.

Abstract: The invention provides a lighting device (1) comprising one or more light sources (10) arranged to generate light, an accommodating device (5) having an external boundary (2) which is at least partly translucent and is arranged to accommodate the one or more light sources and a controller (40). The lighting device can generate two types of light. One or more lighting parameters selected from the group consisting of the first luminous intensity of the first type of light, the second luminous intensity of the second type of light, the color point of the first type of light and the color point of the second type of light can be controlled. This allows task lighting and atmosphere lighting. The invention is also directed to a method of providing a wake-up stimulus by means of such a lighting device.

Abstract: The invention relates to a method and a device for grouping at least three lamps (1) and for assigning the lamps (1) to at least one operating unit. It is time-intensive to equip one or a plurality of rooms or halls within a building with lamps (1), particularly a grouping of lamps (1), and assigning lamps (1) to at least one operating unit. Therefore, grouping of lamps (1) and assigning the lamps (1) to at least one operating unit should be simplified. In accordance with the invention, a lamp (1) emits light and the other lamps (1) measure light, and distances between the lamps (1) are determined in dependence upon at least one light value and the lamps (1) are assigned to at least one operating unit in dependence upon the distances.

Abstract: Light source having a plurality of light elements (207) and a control system for controlling the light elements. The control system comprises a plurality of light element controllers (213), each connected to a respective light element (207), and arranged to obtain light element data; and a bus interface (203), which is connected to the light element controllers (213) via a light source bus (209). The bus interface (203) provides the light element controllers (213) with a general command, and the light element controllers generate light element drive signals on basis of the general command and the light element data.

Abstract: The present invention is an apparatus to enhance the Life of LED devices in an LED matrix for illumination. It comprises of a spare LED matrix in addition to a main LED matrix. It further comprises of a constant current source which is the power source. Such constant current source is coupled directly to said main LED matrix and powers it up accordingly. In adverse conditions, say when the ambient temperature is high, continuous operation of said main LED matrix at full power will deteriorate the LED life. A power converter coupled to said constant current source operates and draws current to power on said spare LED matrix. This relieves said main LED matrix from full power and the reduction in illumination is largely compensated by said spare LED matrix. This invention further comprises a controller which senses temperature and other parameters and operates said spare LED matrix intelligently. The present invention is also a method to operate said apparatus to maximize LED life or to maximize illumination.