Abstract: A lighting system includes a lighting panel having a string of solid state lighting devices and a current supply circuit having a voltage input terminal, a control input terminal, and first and second output terminals coupled to the string of solid state lighting devices. The current supply circuit is configured to supply an on-state drive current to the string of solid state lighting devices in response to a control signal. The current supply circuit includes a charging inductor coupled to the voltage input terminal and an output capacitor coupled to the first output terminal. The current supply circuit is configured to operate in continuous conduction mode in which current continuously flows through the charging inductor while the on-state drive current is supplied to the string of solid state light emitting devices.

Abstract: A first LED group including a plurality of LEDs is regularly arranged in a toric shape on the circumference of a center of an approximately rectangular substrate which is formed of ceramics. In addition, the first LED group including the plurality of LEDs is entirely covered in a toric shape with a sealing member. In addition, a second LED group including a plurality of LEDs is regularly arranged in a grid shape in the vicinity of the center of the approximately rectangular substrate. In addition, the LED group including the plurality of LEDs is entirely covered with a sealing member. In addition, the sealing member entirely covers the inside of the toric portion of a first region.

Abstract: A lighting device includes a DC/DC power converter, a controller/processor electrically connected to the DC/DC power converter, a light emitting diode (LED) current control circuit communicably coupled to the controller/processor and electrically connected to the DC/DC power converter, and two or more LEDs comprising at least a first color LED and a second color LED electrically connected to the LED current control circuit. The LED current control circuit provides an on/off signal having a cycle time to each LED in response to one or more control signals received from the controller/processor such that the two or more LEDs produce a blended light having a specified color based on how long each LED is turned ON and/or OFF during the cycle time.

Abstract: A system and method for controlled illumination in a bioanalysis or other system where excitation of fluorescent molecules is desirable. In an embodiment, an illumination system is described which can provide excitation light at a controlled intensity to provide quantitative results. In an embodiment, a solid state light engine is described which includes a plurality of color channels each providing light output suitable for exciting a fluorescent molecule, a light to frequency converter which receives a portion of the light output, a counter which maintains a count of a signal from the light to frequency converter, and a light intensity circuit, responsive to the counter, which adjusts the color channels to control the intensity of the light output.

Abstract: A lighting device includes a DC/DC power converter, a controller/processor electrically connected to the DC/DC power converter, a light emitting diode (LED) current control circuit communicably coupled to the controller/processor and electrically connected to the DC/DC power converter, and two or more LEDs comprising at least a first color LED and a second color LED electrically connected to the LED current control circuit. The LED current control circuit provides an on/off signal having a cycle time to each LED in response to one or more control signals received from the controller/processor such that the two or more LEDs produce a blended light having a specified color based on how long each LED is turned ON and/or OFF during the cycle time.

Abstract: A lighting device comprises groups of solid state light emitters, a sensor and circuitry. If the emitters are illuminated, the sensor is exposed to combined light from the groups, and senses only a portion of the combined light. The circuitry adjusts current applied to at least one of the emitters based on an intensity of the light sensed. Also, a device comprising emitters, a circuit board and a sensor, at least one of the emitters being positioned on the first circuit board and the sensor being spaced from the circuit board. Also, a lighting device comprising emitters, a sensor, and circuitry which adjusts current applied an emitters based on detection by the first sensor, the circuitry comprising a differential amplifier circuit. Also, a lighting device, comprising light emitters and circuitry which adjusts current applied to only some of the emitters based on ambient temperature. Also, methods of lighting.

Abstract: Technologies are generally described herein for controlling and using integrated occupancy and ambient light sensors. In some examples, a lighting device includes an illumination source, a light sensor, and a transceiver. A determination can be made to determine if the illumination source is operating in an on mode of operation or an off mode of operation. In response to determining that the illumination source is operating in the off mode of operation, an instruction can be received at the lighting device to pulse operation of the illumination source to emit a light pulse. The lighting device can also be configured to receive an instruction to compressively sense, using the light sensor, a light level associated with an area illuminated by the light pulse. The lighting device can output data indicating the light level compressively sensed by the light sensor.

Abstract: Lighting and control systems and methods for a lighting node and a remote control device are disclosed. The remote control device may be coupled to the lighting node via an identification process, such as broadcasting an identification request from the remote control device to nearby lighting nodes. The lighting node can respond to the identification request by sending an identifier to the remote control device such that future commands sent from the remote control device is limited to be responded by the lighting node having the identifier stored thereon. Once coupled, the remote control device can adjust spectral content produced by the lighting node based on user-configuration or a color profile captured via an optical sensor. The adjustment via the remote control device may further include calibration and recalibration of the lighting node utilizing a feedback mechanism with the optical sensor.

Abstract: An apparatus is used to tune the color produced by an LED-based lamp to a desired color or color temperature. To support tuning, the lamp can include two or more independently addressable groups of LEDs. Color or color temperature is tuned by controllably dividing an input current among the groups of LEDs. The apparatus determines an optimal division of the input current based on a linear interpolation between measured values of color or color temperature produced by at least two different divisions of the input current.

Abstract: An illumination system includes an excitation light source that emits excitation light, a phosphor unit that converts the excitation light emitted from the excitation light source into fluorescence to emit the fluorescence toward an illuminated object and a light source device including the excitation light source and the phosphor unit. The illumination system further includes a state confirming device that confirms a state of the light source device based on the state of the phosphor unit when connected to the light source device and the phosphor unit emits the fluorescence.

Abstract: Apparatuses, methods and systems for lighting fixture determining its power usage and monitoring its operational health are disclosed. One embodiment includes a method of a lighting fixture determining its power usage. The method includes sensing, by an ambient light sensor, an intensity of light emitted from the lighting fixture, and estimating power usage of the lighting fixture based on the sensed intensity of light.

Abstract: A portable device comprising a light detector, a correction calculator and a correction output element. In some aspects, (1) correction (and/or adjustment) is of color point, lumen output, or both, (2) the portable device is a smart phone or a computing device, and/or (3) a wireless correction signal is transmitted and received. Lighting system, comprising a light source, and a portable device that comprises a light detector, a correction calculator, and a correction output element. Lighting device comprising a light source and a receiver. A method comprising detecting light with a light detector of a portable device, generating a correction signal, and outputting the correction signal with a correction output element of the portable device. Method comprising placing a portable device in a calibration location, illuminating a lighting device, and detecting light emitted from the lighting device with a light detector of the portable device that has a correction calculator.

Abstract: The invention relates to a method for improving energy efficiency in a lighting system having at least one light source (3), wherein the light source (3) can be connected to an external electrical energy source, for example the grid, for power supply purposes via an operating device (2). In order to avoid standby losses which arise when the operating device (2) needs to be connected to the grid even in the inactive state in order to generate the necessary runup energy for a semiconductor IC (8) when a switch-on command arrives via the bus, it is proposed that additional electrical energy is recovered from the light from the light source (3) which is not used for lighting purposes or from the direct or indirect light from neighbouring luminaires (2); or from the ambient light by means of photovoltaic energy conversion and is supplied to the operating device as runup energy for the semiconductor IC (8). In this way, the operating device (2) can be isolated from the grid at least during the inactive state.

Abstract: A method of controlling media projectors includes providing at least one electromagnetic detector having a field of view directed toward a three dimensional space, and photogrammetrically characterizing at least a portion of the field of view. There is provided at least one media projector that projects at least an electromagnetic signal and a projection controller that moves one or more media projectors in at least two dimensions. At least three measurement locations are obtained within the at least a portion of the field of view by moving the media projector in at least two dimensions. The at least one electromagnetic detector is used to detect the measurement locations within the three dimensional space using the electromagnetic detector to obtain photogrammetric data. The projection controller is calibrated based on the photogrammetric data.

Abstract: A power management system for a lighting system including at least one lighting emitting diode is disclosed. In one embodiment, the light emitting diode(s) of the lighting system are operated under a constant temperature. In another embodiment, the light emitting diode(s) of the lighting system are operated under a constant temperature difference to the ambient temperature. A thermal feedback loop is employed to achieve the constant temperature or the constant temperature difference.

Abstract: An opto-electronic measuring arrangement being independent from extraneous light includes a transmission light source and a compensation light source which sequentially emit light on a clocked phase basis. The emitted light is respectively phase-shifted. The light sources can be controlled such that the clock-synchronous signal difference between different phases becomes zero. A basic coupling light source transmits light directly to the optical receiver without the light being influenced by the measuring object. The basic coupling control current is so that a desired sensitivity of the measuring arrangement is achieved and/or a desired operating point can be set. The controllable current source for generating a clocked transmission control current and the controllable basic coupling current source for generating a clocked basic coupling control current are phase-synchronously clocked.

Abstract: A light emitting apparatus having a plurality of light sources comprises a brightness sensor; a first malfunction detecting unit configured to detect any malfunction of each of the light sources; a second malfunction detecting unit configured to detect any malfunction of the brightness sensor; a storage unit configured to store a target value of a detected value of the brightness of each of the light sources; and a control unit configured to determine a light emission control value of each of the light sources so as to decrease a difference between the target value and the detected value of the brightness of each of the light sources; wherein the control unit allows the light emission control value to be set to a fixed value if the malfunction of at least any one of the light source and the brightness sensor is detected.

Abstract: A regulating system includes a tricolor LED system including at least one first LED that emits light having a first color, at least one second LED that emits light having a second color, and at least one third LED that emits light having a third color, at least one fourth LED that emits light having a fourth color, a sensor that detects the light emitted by the LEDs and generating sensor signals representing characteristics of the light, a controller that outputs control signals depending on the sensor signals and reference values, and LED drivers that drive the first, second, third and fourth LEDs depending on the control signals.

Abstract: Light-emitting devices (100) and methods for operating light-emitting devices are disclosed. Each of the light-emitting devices (100) comprises a plurality of light sources (112A-112F) for illuminating a target (120), wherein each of the light sources is configured to emit light within a predetermined color range. Each of the light-emitting devices comprises means (140) for automatically adjusting the spectral power distribution of light-emitted by the light-emitting device on basis of the color of the target or a region of the target illuminated by the light-emitting device, such that light emitted by the light-emitting device is made increasingly compliant or even compliant with a criteria of a predetermined color characteristics.

Abstract: A device and method, which are utilized in an optical apparatus, for protecting eyes are disclosed. The optical apparatus includes a scanning-mirror component and a visible light source which is optically coupled to the scanning-mirror component. The optical apparatus emits a visible light beam to the scanning-mirror component by using the visible light source. The scanning-mirror component then reflects the visible light beam to emit the visible light beam to a scanning region. The device and the method for protecting eyes can determine at least one eye region in the scanning region, and then make the optical apparatus stop emitting the visible light beam at least within the eye region.

Abstract: A system and method for metered dosage illumination in a bioanalysis or other system includes an illumination system or subsystem that can provide optimized amounts of excitation light within the short exposure times necessary to measure fast biological activity. The amount of light can be precisely measured to provide quantitative results. The light flux can be precisely controlled to generate a prescribed minimum amount of light, in order to reduce adverse lighting effects on both fluors and samples. The system and method is particularly useful in any quality-control, analysis, or assessment-based environment. Typical research and development applications can include quality control, instrument calibration, and light output standardization; while clinical and diagnostics applications can include clinical monitoring, bioassay calibration and control for diagnostics, treatment and or therapeutic evaluation.

Abstract: A back light unit includes a first light source which generates first light in a first wavelength range, a second light source which generates second light in a second wavelength range, and a first wavelength compensating part which adjusts a wavelength of the first light controlling a driving current, which is applied to the first light source.

Abstract: Reduction of luminance dispersion of a plurality of light-emitting panels combined into one light-emitting device is achieved by the use of a new light-emitting device which has a photosensor, a plurality of light-emitting panels, DC/DC converters connected to their respective light-emitting panels, and a control circuit configured to control output currents of the DC/DC converters in accordance with illuminance data acquired with the photosensor. The control circuit successively turns on the plurality of light-emitting panels, and controls the output currents of the DC/DC converters in accordance with differences of the illuminance data acquired with the photosensor when the light-emitting panels are turned on.

Abstract: Methods and systems herein provide for determining lighting contributions of light fixtures to an environment. In one embodiment, a system includes a light sensor and a controller. The light sensor generates light level data based on measured light levels. The controller determines a nominal light level based on the light level data, and identifies an optical burst pattern in the light level data generated by a light fixture. The controller then determines a lighting contribution of the light fixture based on the optical burst pattern and the nominal light level.

Abstract: A failsafe lighting system (1) comprises a lamp (L) and monitoring circuitry for monitoring the correct functioning of the lamp (L), the monitoring circuitry comprising an optical sensor (26) positioned for receiving light generated by the lamp (L). The monitoring circuitry comprises a self-oscillating loop (25) which includes the lamp (L) and the optical sensor (26), wherein the optical path between the lamp (L) and the optical sensor (26) is an essential portion of the loop (25) such that the loop (25) can only oscillate if the optical sensor (26) receives sufficient light from the lamp (L).

Abstract: Solid state transducer devices with independently controlled regions, and associated systems and methods are disclosed. A solid state transducer device in accordance with a particular embodiment includes a transducer structure having a first semiconductor material, a second semiconductor material and an active region between the first and second semiconductor materials, the active region including a continuous portion having a first region and a second region. A first contact is electrically connected to the first semiconductor material to direct a first electrical input to the first region along a first path, and a second contact electrically spaced apart from the first contact and connected to the first semiconductor material to direct a second electrical input to the second region along a second path different than the first path. A third electrical contact is electrically connected to the second semiconductor material.

Abstract: An adjustable spectrum LED solar simulator method and system which provides power to LEDs, senses the LED output, compares the LED output to a predetermined norm, and adjusts the LED outputs accordingly. An adjustable spectrum LED solar simulator system includes a multiplicity of LEDs of a number of different color wavelength ranges, an LED driver system for providing power to the LEDs, a sensor system for sensing the output of the LEDs and a controller responsive to the sensor system for comparing the color spectrum of the output of the LEDs to a desired solar spectrum and enables the driver system to adjust the power to the LEDs to more closely match the desired solar spectrum. The solar simulator system may include a modulator structure of hierarchical assemblies. Solar simulator calibration is also disclosed.

Abstract: There is provided a lighting device, comprising at least one light emitter, at least one reflector and at least one sensor. The sensor is positioned within a region which receives direct light from the light emitter when the light emitter is emitting light. In some embodiments, the light emitter comprises one or more light emitting diode. In some embodiments, the sensor is positioned between the light emitter and a power supply. In some embodiments, the reflector comprises at least one opening, and light emitted by the light emitter passes through the opening to the sensor. In some embodiments, the sensor is sensitive to only some wavelengths of visible light. Some embodiments are back-reflecting lamps, and some are forward-reflecting lamps.

Abstract: A light-emitting element driving circuit comprising, a light-emitting element, a driving unit which has a control terminal and is configured to drive the light-emitting element according to a potential of the control terminal, a node connected to the control terminal, a monitor configured to monitor an emitted light amount of the light-emitting element, a potential control unit configured to control a potential of the node so that the emitted light amount of the light-emitting element approaches a target value, and an auxiliary potential control unit configured to assist potential control of the node by the potential control unit when a difference between the emitted light amount of the light-emitting element detected by the monitor and the target value is larger than a reference amount.

Abstract: The present invention generally relates to methods of controlling UV lamp output to increase irradiance uniformity. The methods generally include determining a baseline irradiance within a chamber, determining the relative irradiance on a substrate corresponding to a first lamp and a second lamp, and determining correction or compensation factors based on the relative irradiances and the baseline irradiance. The lamps are then adjusted via closed loop control using the correction or compensation factors to individually adjust the lamps to the desired output. The lamps may optionally be adjusted to equal irradiances prior to adjusting the lamps to the desired output. The closed loop control ensures process uniformity from substrate to substrate. The irradiance measurement and the correction or compensation factors allow for adjustment of lamp set points due to chamber component degradation, chamber component replacement, or chamber cleaning.

Abstract: A solid state relay includes a light-receiving element, output terminals configured to connect to an AC power supply and a load, a first connection line connecting a first end of the light-receiving element to a first output terminal, a second connection line that connects a second end of the light-receiving element to a second output terminal, a switching element between the first connection line and the second connection and configured to be turned on by the current outputted from the light-receiving element, and a snubber circuit in which a capacitor and a resistor are connected in series. The resistor of the snubber circuit connects to the first connection line between one of the first and second end of the light-receiving element and an end of the switching element, and an over-current protection element connects to the first connection line between the resistor and an end of the switching element.

Abstract: Disclosed is a solid-state light source based on a light emitting diode (LED) array driven by a constant current power source with an active feedback control. This system can be implemented for broad frequency ranges or for narrow band frequencies depending on the characteristics of the LEDs chosen to populate the array and the geometry of the array. The invention can be used as an excitation light source for fluorescent microscopy and flow cytometry applications as an efficient and stable alternative to existing light sources such as broadband mercury vapor bulbs and plasma-based light sources. Benefits of the current invention include: durability; stability; reduced operating expenses; reduced variance of output; and increased accuracy of frequency and amplitude. This system will provide benefits as the excitation mechanism in fluorescent identification and measurement systems such as microscopy and flow cytometry.

Abstract: A light source control apparatus that do not always require calculations for the upper limit of driving current when characteristic of a light source varies. The light source control apparatus controls a light source that exhibits a characteristic including an uptrend region where the light amount increases with increasing driving current and a downtrend region where the light amount decreases with increasing driving current. A determination unit determines whether the light source is in the uptrend or downtrend region based on signals from a light variation detection unit and a current variation detection unit. A control unit matches the light amount (L) with target light amount (T), by increasing the driving current when L<T in the uptrend region or when L>T in the downtrend region, and by decreasing the driving current when L>T in the uptrend region and when L<T in the downtrend region.

Abstract: An LED-based light tube for use in a conventional fluorescent fixture includes a housing including a light transmitting portion, at least one electrical connector attached to the housing and configured for engagement with the conventional fluorescent fixture, at least one LED arranged to produce light in a direction toward the light transmitting portion, a sensor operable to detect a brightness level and output a signal corresponding to the detected brightness level, and a controller in electrical communication with the at least one electrical connector, operable to: compare the signal to a predetermined value corresponding to a desired brightness level and control an amount of power provided to the at least one LED in response to the signal to adjust the light produced by the at least one LED to achieve the desired brightness level.

Abstract: A backlight control circuit and method thereof are provided to control the backlight of a backlight module so as to enhance the dynamic contrast ratio and save power. The backlight control circuit includes an average luminance detection circuit, a luminance distribution detection unit, a pulse width control circuit and a pulse width modulator. The average luminance detection circuit detects the average luminance of a frame which includes a plurality of pixels; the luminance distribution detection unit detects the pixel luminance distribution of the frame; the pulse width control circuit generates a pulse width control signal according to the average luminance and the pixel luminance distribution of the frame; and the pulse width modulator generates a pulse width modulation (PWM) signal according to the pulse width control signal, so as to control the backlight of the backlight module.

Abstract: A light emitting device for use as a hair removal device is provided. The light emiting device has at least one radiation source for electromagnetic radiation providing at least one operating beam during operation of the device, a housing being intransparent for the operating beam having an output opening, at least one radiation source for electromagnetic radiation providing at least one sensing beam during operation of the device, at least one detector for detecting the sensing beam, at least one sensing window having a contact boundary surface, and a controller communicating with the radiation source providing the operating beam and with a detector and being operable to influence operation of the radiation source providing the operating beam responsive to the sensing beam detected at the detector.

Abstract: A lighting system uses interior and exterior light sensors for detecting lighting level and colour. A lighting unit has a controlled colour and intensity so that a colour match zone can be defined where the interior space lighting has colour temperature based on the exterior lighting conditions.

Abstract: A system and method for metered dosage illumination in a bioanalysis or other system. In accordance with an embodiment, an illumination system or subsystem is described that can provide optimized amounts of excitation light within the short exposure times necessary to measure fast biological activity. The amount of light can be precisely measured to provide quantitative results. The light flux can also be precisely controlled to generate only a prescribed minimum amount of light, in order to reduce adverse lighting effects on both fluors and samples. Although the examples herein illustrate the providing of metered dosage illumination in the context of a bioanalysis system, the techniques can be similarly used to provide metered dosage illumination in the context of other types of system.

Abstract: A method for communication between a lighting node and a controller is described. One embodiment of the method includes transmitting a command from the controller based on a target illumination profile stored on the controller to the lighting node utilizing a controller radio device and receiving the command from the controller at the lighting node utilizing a node radio device. The method may also include generating illumination having a spectral content from the lighting node utilizing at least a light emitting diode; and receiving the spectral content from the lighting node at the controller utilizing an optical sensor.

Abstract: A system provides white light having a selectable spectral characteristic (e.g. a selectable color temperature and intensity) using a combination of sources (e.g. LEDs) emitting light of four, five, or six different characteristics, for example, one or more white LEDs, and one or more LEDs of each of three primary colors plus cyan and royal blue. A microcontroller can maintain a desired spectral characteristic, e.g. for white light at a selected point on or within a desired range of the black body curve. Further, the microcontroller provides tunability of the spectral characteristic and intensity of the white luminaire. One channel driver drives the one or more first color LEDs (white in our example) as well as the one or more second color LEDs which are connected in series to the first channel driver. The other light sources are each driven by separate drivers on separate channels.

Abstract: An AC LED lamp adaptive to ambient luminance has a lamp shell, an LED lamp board, an LED driving circuit and a luminance sensor. The LED lamp board, the LED driving circuit and the luminance sensor are mounted inside the lamp shell and are electrically connected to each other. The luminance sensor is mounted on the LED lamp board, is capable of sensing light emitted from the LED lamp board. Multiple LED elements on the LED lamp board are alternately driven to turn on and turn off and a luminance signal is sensed by the luminance sensor while the LED elements are driven to turn off. As the luminance signal contains an ambient luminance only, accurate ambient luminance for the lamp can be therefore acquired.

Abstract: A modularized LED lamp is disclosed. Embodiments of the present invention provide an LED lamp in which digital and/or analog communication takes place between the LED module and the power supply unit (PSU) of the lamp. A controller in the LED module sends signals to the PSU, allowing separation of the two parts so that each part can be manufactured independently as opposed to being manufactured as a calibrated, matched pair. The LED module, by way of its controller, provides information to the PSU that allows the power supply to adjust its drive current appropriately. The PSU controller can also respond to operating temperature variations of the LEDs in order to provide thermal shutdown, brightness compensation, and other control if needed. In some embodiments, a controller in the PSU also responds to an external dimming input.

Abstract: A compensation circuit of organic light emitting diode comprising a first capacitor, a second capacitor, a stabilizer unit, a third transistor, an organic light emitting diode and a driver unit. The stabilizer unit comprises a first transistor, a second transistor and a photodiode. The driver unit comprises a fourth transistor, a fifth transistor and a sixth transistor. The fifth transistor is used for driving the organic light emitting diode. The first transistor, the second transistor, the third transistor, the fourth transistor and the sixth transistor are used as switches. The first capacitor is used as a compensation capacitor. The second capacitor is used for storing a data voltage. By controlling a voltage of a node in the circuit, the current of the organic light emitting diode can be increased to maintain a stable brightness of the organic light emitting diode.

Abstract: This invention relates to assemblies used as night lights and contains certain embodiments that improve, add features, and/or lower the cost of the type of momentary night light defined by U.S. Pat. No. 7,253,570. The words ‘momentary night light assembly’ as used in this invention means a light that remains lit for only a short fixed period of time following a transition from light to dark of the local ambient light. It then turns itself off after a short time period until another light to dark transition occurs. The words ‘night light’ as used herein means a light that remains on while the local ambient light is dark following a light to dark transition.

Abstract: A building lighting control system includes a central building server, distributed zone controllers, and light sensors and control units in each zone. Using occupant lighting preferences, occupancy state, and light levels, each zone controller computes a utility curve which represents the relationship between energy use and service level in the zone. The building server zone receives utility curves from all the zones and allocates energy units to the zones based on the utility curves using a utility-based trading algorithm in order to optimize service levels with minimal energy. Each zone controller then distributes energy to lights in its zone based on energy units allocated to the zone by the building server and based also on influence matrices representing the influences of the lights in the zone upon the sensors in the zone. The building server may also compute and output long-term operational information of the building.

Abstract: A system and method for streetlight control is provided. A lamp sensor inside a reflector of the streetlight is utilized to detect the output of a lamp of the streetlight. During daytime periods when the lamp is OFF, the lamp sensor is utilized to act as a day/night sensor by detecting ambient light near the lamp. When the ambient light level falls below a sufficient level indicative that night is approaching the lamp is turned ON and the lamp sensor utilized to detect the lamp output of the streetlight.

Abstract: In a single lighting device including a large number of light-emitting elements (LEEs), the LEEs are divided into separately powered groups, and different combinations of the groups are fully energized to achieve the desired overall brightness. In some embodiments, the number of LEEs in each group has a binary relationship to the other groups. The resolution of the dimming is the brightness of the smallest group. In one example of five binary weighted groups of LEEs, 32 brightness levels can be achieved while the LEEs in the energized groups are fully ON. Thus, since there is no high frequency switching, there is substantially no power dissipation by the dimming control system, and there is limited noise or EMI created. The dimming control can be easily implemented with a logic circuit controlling a transistor switch for each group.

Abstract: The invention describes a method of driving an arc-discharge lamp (1), which method comprises the steps of detecting a mechanically induced fluctuation in luminous flux of the lamp (1) occurring as a result of a physical displacement of the discharge arc (2), determining a characteristic (43, 51, 63) of the mechanically induced fluctuation in luminous flux of the lamp (1), and adjusting the lamp power on the basis of the determined characteristic (43, 51, 63) to suppress the mechanically induced fluctuation in luminous flux of the lamp (1).

Abstract: A low voltage control system includes a controller having a plurality of switched power lines and a plurality of DC lighting loads. Each DC lighting load includes at least one DC lighting element. Each DC lighting load has an associated switch downstream from the controller that selectively connects the at least one DC lighting element to one of the plurality of switched power lines. At least one first input device includes at least one of an occupancy sensor, a light intensity sensor, or a programmable digital timer. The controller selectively powers the switched power lines in response to sensor data received from the first input device or commands received from at least one wired or wireless switch in communication with the controller.

Abstract: In various embodiments, a street lighting device with a first light source for illuminating the street plane from above is provided. The device may include a second light source located at a closer position to the street plane than said first light source; a sensor sensitive to the occurrence of conditions of reduced ambient visibility; and a controller connected to said sensor and capable of activating said second light source in the presence of said conditions of reduced ambient visibility.