Abstract: A circuit for driving a light-emitting diode (LED) load and a direct current to direct current (DC-DC) converter includes a first sampling sub-circuit, a driving circuit. The first sampling sub-circuit is configured to generate a current signal representing a load current of the LED load. The driving circuit is configured to receive a brightness adjustment signal and a frequency adjustment signal; generate a first control signal, based on the current signal and the brightness adjustment signal, for controlling an output current of the DC-DC converter; and generate a second control signal, based on the frequency adjustment signal, for controlling a switching frequency of the LED load.

Abstract: An intelligent lighting device control system includes a plurality of lighting devices and an intelligent lighting device controller. The intelligent lighting device controller includes a detecting module, a main power source module and an intelligent control module. The detecting module has a detecting circuit. The main power source module includes a plurality of first electrode connectors and a common electrode connector. The first electrode connectors are connected to the detecting circuit and connected to the first electrodes of the lighting devices via the detecting circuit. The common second electrode connector is connected to the second electrodes of the lighting devices and outputs an electricity signal to drive the lighting devices, such that the detecting circuit generates a plurality of detecting signals. The intelligent control module generates a feedback signal according to the detecting signals and the main power source module adjusts the electricity signal according to the feedback signal.

Abstract: A lighting device including an LED light source, wherein the LED light source includes a first LED strand for generating a first light with a first correlated color temperature and a second LED strand for generating a second light with a second color temperature different from the first color temperature. The lighting device further comprises control electronics with a controllable LED driver for driving the LED light source, wherein the control electronics comprise a switch for switching between the first LED strand and the second LED strand so that either the first LED strand or the second LED strand is activated depending on the switch position. A lighting system comprising the lighting device is further disclosed.

Abstract: A method and system for controlling illumination according to eye safety standards. The method includes a processor retrieving from a memory of an illumination module, device information indicative of properties of the illumination module. The device information includes a plurality of parameters of an illumination element of the illumination module, and a maximum constant for the illumination element. The maximum constant is associated with a desired eye safety standard and is also indicative of a relationship between at least two parameters of the illumination element. The method further includes receiving, from a user, a desired parameter value for one of the parameters of the plurality of parameters. The processor determines a test constant from the desired parameter value, and the processor compares the test constant and maximum constant to determine if the desired parameter value is an acceptable value.

Abstract: A powerline communication control system for controlling a lighting unit, such as an LED lighting unit, including a master controller for receiving lighting unit control inputs from a lighting controller and generating corresponding lighting unit command outputs in a lighting system command format and transmission mode and superimposing the lighting unit command outputs onto the power distribution system and at least one lighting slave unit for receiving the lighting command signal, separating the lighting command signal from the power signal and for providing lighting unit control commands to the at least one lighting unit to control illumination thereof, entirely within a modem embedded into a microcontroller.

Abstract: Provided is a programmable light source output control device. A light source output control device includes electronic fuses, a power stage configured to receive external power, generate actuating power according to the external power and a state of each of the electronic fuses, and supply the actuating power to a light source, and a setting circuit configured to set the state of each of the electronic fuses.

Abstract: Disclosed are apparatus for controlling a lamp and a method thereof. The apparatus for controlling a lamp includes an information collection device that receives light amount information and temperature information of LED chips, which correspond to a plurality of LED boards, respectively, from the plurality of LED boards through one port, and a controller that controls a driving current for driving the LED chip based on the light amount information of the LED chip or the temperature information of the LED chip.

Abstract: A power receiver apparatus is movable under water. The power receiver apparatus includes: a power receiver device configured to receive power wirelessly transmitted from a power transmitter apparatus; a power supply device including a storage battery and configured to charge the storage battery based on received power received by the power receiver device; a first sensor configured to detect a rectified voltage value rectified based on the received power; a second sensor configured to detect a charging current value to the storage battery charged by the power supply device; a processor configured to determine a power transmission voltage value corresponding to the power wirelessly transmitted from the power transmitter apparatus based on the rectified voltage value and the charging current value; and a communication device configured to transmit the power transmission voltage value determined by the processor to the power transmitter apparatus.

Abstract: An LED light with an LED module which has one or more LEDs and an LED driver for power supply to the LEDs. The LED module is at least partially coated with a photoluminescent phosphor, which is configured for absorption of light energy from the LEDs and time-delayed emission of the stored light energy, and the LED driver has at least one electronic component for smoothing the current to be output to the LEDs.

Abstract: A horticultural luminaire includes a first and second horticultural light sources to provide growth lighting to a plant at a first and second wavelengths. A control unit provides first lighting control signals to the first horticultural light source to modulate the first growth lighting and provides second lighting control signals to the second horticultural light source to modulate the second growth lighting. A LiDAR sensor is connected to the lighting control unit to receive the first and second control signals, and having optics to detect reflected first and second growth lighting to determine the distance from plant to sensor and a biometric property of the plant from the received first and second control signals and detected first and second reflected second growth lighting. In some implementations the LiDAR sensor and first and second horticultural light sources are integrated into the horticultural luminaire.

Abstract: An overhead lighting fixture containing both visible light sources and UV light sources is disclosed herein. UV light can sanitize/disinfect the surrounding environment after the environment over a period of about 30-45 minutes. In this way, viruses, germs, bacteria, mold, and the like can be destroyed to clean the air and/or surfaces (e.g., furniture). Accordingly, embodiments of the present invention provide a controllable UV lighting assembly that can produce UV light to sanitize/disinfect an area and can be automatically disabled to prevent UV light exposure to those in the area using a motion sensor. The lighting assembly can produce visible light while the UV light source is disabled. According to some embodiments, the duration of UV light production is controlled by a timer for power savings.

Abstract: A dimming circuit for dimming a current flowing through a light emitting device, having: a multi-function pin, configured to receive a dimming signal; wherein when the dimming signal is an analog voltage signal, an amplitude of the current flowing through the light emitting device is regulated based on the dimming signal; when the dimming signal is a pulse signal and a frequency of the dimming signal is in a first frequency range, a duty cycle of the current flowing through the light emitting device is regulated based on the dimming signal; and when the dimming signal is the pulse signal and the frequency of the dimming signal is in a second frequency range, the amplitude of the current flowing through the light emitting device is regulated based on the dimming signal.

Abstract: The present disclosure provides methods and structures for controlling characteristics of light being projected from a light source. In one embodiment, the method includes selecting a color setting of light to be projected by a light engine having at least one light emitting diode; and monitoring temperature of the light engine with a thermistor. The changes in resistance measurements taken from the thermistor are correlated to changes in the temperature of the light engine. The method for controlling characteristics of light being projected from the light source may further include setting characteristics of the electrical signal to energize the light emitting diodes of the light engine to provide the color setting selected at the temperature of the light engine measured using the thermistor.

Abstract: The present disclosure provides a light-emitting diode lamp designed to replace an incandescent filament bulb for illumination purposes in a transportation vehicle and a light-emitting diode circuit associated therewith.

Abstract: A method for operating an optoelectronic semiconductor device. The semiconductor device includes a first optoelectronic semiconductor chip for generating, for example, blue light, an optional second optoelectronic semiconductor chip for generating, for example, green light, and a third optoelectronic semiconductor chip for generating, for example, red light. The semiconductor device also includes a driver unit which supplies the semiconductor chips with current during operation. The third semiconductor chip is operated on the basis of a temperature-brightness characteristic curve stored in the driver unit. The temperature-brightness characteristic curve is configured for a minimum color location deviation over an intended operating temperature range, relative to at least one reference color location.

Abstract: A load control device for controlling the amount of power delivered to an electrical load (e.g., an LED light source) includes first and second semiconductor switches, a transformer, a capacitor, a controller, and a current sense circuit operable to receive a sense voltage representative of a primary current conducted through a primary winding of the transformer. The primary winding is coupled in series with a semiconductor switch, while a secondary winding is adapted to be operatively coupled to the load. The capacitor is electrically coupled between the junction of the first and second semiconductor switches and the primary winding. The current sense circuit receives a sense voltage and averages the sense voltage when the first semiconductor switch is conductive, so as to generate a load current control signal that is representative of a real component of a load current conducted through the load.

Abstract: A driving device is provided. The driving device includes a signal processing circuit and a driving circuit. The signal processing circuit is configured to generate a current input signal according to a target current signal. The driving circuit is configured to receive the current input signal and generate a current output signal according to the current input signal to drive a light emitting element. In a first time interval, the current input signal gradually rises from a first current value to a target current value in a continuous or segmented manner according to a rising slope. Further, a control method of the driving device and a lighting system including the driving device are also provided.

Abstract: A dimming signal processing circuit having multiple functions includes a dimming signal input terminal and a dimming signal output terminal, and further includes an input signal processing circuit, a modulation circuit, an isolation circuit and an output shaping circuit connected in cascade to the dimming signal input terminal, and an oscillation signal output circuit connected to the modulation circuit, wherein the output shaping circuit comprises a plurality of signal output circuits connected to the dimming signal output terminal respectively. The dimming signal processing circuit having multiple functions is low in cost and high in practicability, and meets new laws and regulations and more use requirements.

Abstract: A display device includes: a substrate; a display element layer on one surface of the substrate and including at least one light emitting element emitting light; and a pixel circuit portion on the display element layer and including at least one transistor electrically connected to the light emitting element, wherein the display element layer includes: a first electrode on the substrate and electrically connected to one end of the light emitting element; a second electrode on the substrate and electrically connected to the other end of the light emitting element; and an insulation layer on the substrate including the second electrode, and having a first opening exposing a portion of the second electrode, and wherein the second electrode is electrically connected to the transistor through the first opening.

Abstract: AC-driven light-emitting diode systems and methods are provided for driving LED devices (e.g., LED lighting) using AC power. For example, an integrated circuit includes a first power line and a second power line configured for connection to AC power, and a plurality of LED stages, wherein each LED stage comprises multiple serially-connected LED devices, switches connected to inputs and outputs of the LED stages. The integrated circuit further includes switch control circuitry configured to control the switches to selectively connect one or more of the LED stages to the first and second power lines to empower the LED stages with the AC power.

Abstract: A load control device for controlling the amount of power delivered to an electrical load (e.g., an LED light source) includes first and second semiconductor switches, a transformer, a capacitor, a controller, and a current sense circuit operable to receive a sense voltage representative of a primary current conducting through to a primary winding of the transformer. The primary winding is coupled in series with a semiconductor switch, while a secondary winding is adapted to be operatively coupled to the load. The capacitor is electrically coupled between the junction of the first and second semiconductor switches and the primary winding. The current sense circuit receives a sense voltage and averages the sense voltage when the first semiconductor switch is conductive, so as to generate a load current control signal that is representative of a real component of a load current conducted through the load.

Abstract: A load control system for controlling the amount of power delivered from an AC power source to a plurality of electrical load includes a plurality of independent units responsive to a broadcast controller. Each independent unit includes at least one commander and at least one energy controller for controlling at least one of the electrical loads in response to a control signal received from the commander. The independent units are configured and operate independent of each other. The broadcast controller transmits wireless signals to the energy controllers of the independent units. The energy controllers do not respond to control signals received from the commanders of other independent units, but the energy controllers of both independent units respond to the wireless signals transmitted by broadcast controller. The energy controller may operate in different operating modes in response to the wireless signals transmitted by the broadcast controller.

Abstract: An illumination switch device includes a push button, a plurality of indicator lenses, a holder, a detector, a plurality of light emitters, and a base. The push button has an internal space and an opening. Each indicator lens has a columnar shape. The indicator lenses are juxtaposed in the internal space of the push button. The holder holds the push button such that the push button is movable in a longitudinal direction of each indicator lens. The detector detects a displacement of the push button in the longitudinal direction. The light emitters are respectively disposed opposite one ends of the indicator lenses in the longitudinal direction. The base is made of an opaque resin, and covers side faces of the indicator lenses while being in tight contact with the side faces. The base is integrated with the indicator lenses.

Abstract: A battery information processing system includes an analyzer configured to analyze a result of measurement of an AC impedance of a module M. The analyzer plots the result of measurement of the AC impedance on a first frequency characteristic diagram which is a Bode diagram (a first diagram) relating to a real number component of the AC impedance and on a second frequency characteristic diagram which is a Bode diagram (a second diagram) relating to an imaginary number component of the AC impedance, obtains a polynomial curve L1 by fitting processing onto a result of plotting on the first diagram and obtains a polynomial curve L2 by fitting processing onto a result of plotting on the second diagram, and converts the polynomial curves L1 and L2 into an impedance curve Z on a Nyquist diagram.

Abstract: An elongated microwave powered lamp (1) having one or more bulbs with any length or shape or disposition according to a linear series, straight or curved, includes: at least one transparent elongated bulb (2) containing, in an inner space thereof, a material apt to be excited by microwave irradiation thereby emitting an electromagnetic radiation; a coaxial microwave antenna placed outside the bulb (2) and respectively connected to a microwave source (81) via corresponding antenna lead (91), said bulb (2) and said at least one microwave coaxial antenna being displaced in a close relationship to each other to allow the microwave excitation of said material, wherein the outer tubular conductor of the coaxial antenna (5) has spaced holes (6) formed therethrough and facing the bulb (2), at which microwaves are released toward the bulb.

Abstract: AC-driven light-emitting diode systems and methods are provided for driving LED devices (e.g., LED lighting) using AC power. For example, an integrated circuit includes a first power line and a second power line configured for connection to AC power, and a plurality of LED stages, wherein each LED stage comprises multiple serially-connected LED devices, switches connected to inputs and outputs of the LED stages. The integrated circuit further includes switch control circuitry configured to control the switches to selectively connect one or more of the LED stages to the first and second power lines to empower the LED stages with the AC power.

Abstract: A drive system for an electric motor includes a first inverter that includes first switching elements, a second inverter that includes second switching elements, and a control unit that includes a first inverter control calculation section controlling on-off operation of each of the first switching elements based on a first carrier wave and a first modulation wave, a second inverter control calculation section controlling on-off operation of each of the second switching elements based on a second carrier wave and a second modulation wave, and a control synchronization section synchronizing the first carrier wave with the second carrier wave. When a sum of voltages of the first voltage source and the second voltage source is more than a voltage determination threshold, and torque of a rotating electric machine is smaller than a torque determination threshold, the control synchronization section synchronizes the first carrier wave with the second carrier wave.

Abstract: A power switch includes a bridge-connected switching circuit with (1) a pair of MOSFETs back-to-back in series between line and load connections, an interconnection point of the MOSFETs being a first common connection, and (2) a pair of diodes back-to-back between the line and load connections, an interconnection point of the diodes being a second common connection. A line/load controller has supply inputs connected to the first and second common connections for receiving operating power, and (1) places both MOSFETs in the ON state to deliver normal operating current to the load for normal operation, and (2) places both MOSFETs in the OFF state to deliver (by body diode conduction) a substantially reduced leakage current to the load when the load is not powered for normal operation, the leakage current providing the operating power to the line/load controller.

Abstract: There are provided an information transmitter and an apparatus including the same. The information transmitter includes a signal generator configured to output an information signal including pulses changed from a first state to a second state or a third state and subsequently changed from the second state or the third state to the first state. A time period in which some of the pulses are changed from the first state to the second state or the third state may be shorter than a time period in which some of the pulses are changed from the second state or the third state to the first state. The information transmitter also includes a transmitting coil configured to receive the information signal and generate a magnetic field based on the information signal.

Abstract: A display panel is provided. In the display panel, a plurality of pixels respectively including a plurality of sub pixels are arranged in a matrix form on a glass. Each of the plurality of sub pixels includes a driving circuit disposed on the glass and configured to receive a PAM data voltage and a PWM data voltage, and an inorganic light emitting device configured to emit a light based on a driving current provided from the driving circuit. The PAM data voltage is applied at once to the plurality of pixels included in the display panel. The driving circuit compensates a deviation between driving circuits included in each of the plurality of sub pixels based on a driving voltage of the driving circuit, and controls a pulse width of a driving current having an amplitude corresponding to the applied PAM data voltage based on the applied PWM data voltage.

Abstract: There are provided an information transmitter and an apparatus including the same. The information transmitter includes a signal generator configured to output an information signal including pulses changed from a first state to a second state or a third state and subsequently changed from the second state or the third state to the first state. A time period in which some of the pulses are changed from the first state to the second state or the third state may be shorter than a time period in which some of the pulses are changed from the second state or the third state to the first state. The information transmitter also includes a transmitting coil configured to receive the information signal and generate a magnetic field based on the information signal.

Abstract: An optoelectronic device comprises a substrate; a groove on the substrate; a plurality of semiconductor units on the substrate and separated by the groove, wherein each semiconductor unit comprises a first semiconductor layer, a second semiconductor layer, and an active region interposed between the first semiconductor layer and the second semiconductor layer; a connecting part crossing the groove for connecting two of the plurality of semiconductor units, wherein the connecting part comprises one end on the first semiconductor layer and another end on the second semiconductor layer; a first electrode comprising a plurality of first extensions jointly connected to the one end of the connecting part; and a second electrode comprising a plurality of second extensions jointly connected to the another end of the connecting part, wherein an amount of the plurality of first extensions is different from an amount of the plurality of second extensions.

Abstract: Current through an illumination source is controlled by means of a feedback loop whereby the current is measured and fed back to a current controller, which compares this to a set-point and based thereon outputs a current control signal which controls downstream power circuitry driving the current through the illumination source. This keeps the illumination at a steady dim level. Data is also coded into the illumination by modulating the current control signal, i.e. at the output of the current controller, but prior to the input to the power circuitry. The present disclosure provides a compensation filter arranged to apply a compensation to the error signal, to at least partially remove an effect of a distortion of the current measurement caused by the modulation of the data symbols into the illumination source current.

Abstract: A load control device for controlling the amount of power delivered to an electrical load (e.g., an LED light source) includes first and second semiconductor switches, a transformer, a capacitor, a controller, and a current sense circuit operable to receive a sense voltage representative of a primary current conducting through to a primary winding of the transformer. The primary winding is coupled in series with a semiconductor switch, while a secondary winding is adapted to be operatively coupled to the load. The capacitor is electrically coupled between the junction of the first and second semiconductor switches and the primary winding. The current sense circuit receives a sense voltage and averages the sense voltage when the first semiconductor switch is conductive, so as to generate a load current control signal that is representative of a real component of a load current conducted through the load.

Abstract: A light emitting device, which includes a plurality of light emitting elements each having a different chromaticity of emission light, to emit mixed light produced by mixing the respective emission light of the plurality of light emitting elements together, includes a receiving section to obtain command information on the mixed light, a driving section to perform a PWM drive on the plurality of light emitting elements on the basis of the command information, and a storing section to store correction information to be set on the basis of measurement results on the respective emission light of the plurality of light emitting elements. The driving section is being configured in such a manner as to, on the basis of the correction information, correct a duty ratio in the PWM drive to be set in accordance with the command information, and perform the PWM drive on the plurality of light emitting elements.

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 relates a system for determining a change in a room (1). The invention comprises in particular a self-teaching illuminating system which detects a presence of an individual in an illuminated area. The system comprises lighting means (2) which output light, control means (3) which control the luminous output from the lighting means (2), measuring means (4) which determine a luminous intensity, and an evaluation means (6) which evaluates the luminous intensity determined by the measuring means (4). The evaluation means (6) is designed to detect a change of an object/individual in the room (1), starting from a determined luminous intensity at at least one first time, at which the lighting means (2) outputs no light, and a luminous intensity at at least one second time, at which the lighting means (2) outputs light.

Abstract: An electronic device has a display with a pixel array overlapping an array of temperature sensors. Control circuitry in the device may gather temperature measurements from the temperature sensor array. The control circuitry may apply a global offset to the temperature measurements and may apply a damping factor to the globally offset measurements to produce a two-dimensional temperature profile for the display. A look-up table or other data structure may be used to store information on pixel color correction gain values as a function of temperature. This temperature-gain information and temperature information from the two-dimensional temperature profile may be used by display circuitry in the device to display color-corrected images on the display.

Abstract: An LED lighting device comprises at least one LED selectively energizable to develop light and a control circuit coupled to the LED that develops a command signal comprising first and second command signal components for controlling the at least one LED to cause the LED to develop light comprising a desired brightness in response to the first command signal component. The control circuit controls the at least one LED to cause the LED to develop light comprising a further desired parameter magnitude other than desired brightness in response to the second command signal component, and the first signal component comprises an IEC 0-10 volt analog lighting control.

Abstract: Provided is a light emission device. When the size of an input voltage exceeds a minimum light emission voltage, all light emission elements emit light always irrespective of the size of a voltage, and as the size of the voltage decreases, the light emission device has a configuration in which the light emission elements are connected in parallel with each other, and as the size of the voltage increases, the light emission device has a configuration in which the light emission elements are connected in series with each other.

Abstract: In described examples, a circuit for controlling a light emitting diode (LED) includes a switch control circuit to generate a first control signal for a first switch coupled in parallel with the LED. The switch control circuit generates the first control signal responsive to a magnitude of loop current through the first switch relative to a first reference signal. A switch driver generates a second control signal for a second switch coupled to the first switch via an inductor. The first switch driver generates the second control signal responsive to the magnitude of the loop current through the first switch relative to the first reference signal.

Abstract: A discharge lamp lighting device includes a control unit adapted to control a frequency of the AC electric current supplied to a discharge lamp by a feeding unit, in different manners within a first term and a second term which are alternately repeated, the control unit is adapted to control the frequency of the AC electric current such that, within the first term, the frequency of the AC electric current becomes at least one frequency out of plural set frequencies, and is further adapted to control the frequency of the AC electric current, based on a predetermined frequency and an electric current within the previous first term, such that, within the second term, the frequency of the AC electric current becomes a frequency lower than this predetermined frequency.

Abstract: A load control device for controlling the amount of power delivered to an electrical load (e.g., an LED light source) includes first and second semiconductor switches, a transformer, a capacitor, a controller, and a current sense circuit operable to receive a sense voltage representative of a primary current conducting through to a primary winding of the transformer. The primary winding is coupled in series with a semiconductor switch, while a secondary winding is adapted to be operatively coupled to the load. The capacitor is electrically coupled between the junction of the first and second semiconductor switches and the primary winding. The current sense circuit receives a sense voltage and averages the sense voltage when the first semiconductor switch is conductive, so as to generate a load current control signal that is representative of a real component of a load current conducted through the load.

Abstract: A method and apparatus for a horticultural light for use in a horticultural facility that uses current sharing across any one or more LED strings within the horticultural light. A processor determines the current requirements of the one or more LED strings that are needed to produce a given intensity level. The processor then apportions the current generation capability of a DC-DC converter across all active LED strings using time division multiple access whereby each LED string conducts its apportioned current within its allocated time slot to the mutual exclusion of the remaining active LED strings in the allocated time slot. The processor employs analog (continuous) and/or digital (discontinuous) dimming techniques within each time slot to further modulate the amount of current conducted by any LED string within its allocated time slot.

Abstract: A multi-channel current control circuit and method are disclosed herein. The multi-channel current control includes an operational amplifier provided for a channel; a low pass filter provided for the channel connected to an input terminal of the operational amplifier; a mode control circuit configured to control the low pass filter to have one of predetermined time constants in accordance with predetermined current control mode; and a pulse width modulation circuit configured to generate a pulse width modulation signal provided for the channel; and transfer the pulse width modulation signal to the input terminal of the operational amplifier via the low pass filter. The operational amplifier controls a load current of the channel using an output voltage of the operational amplifier.

Abstract: Herein is disclosed a dual-pathway LED dimmer, including a first reference voltage node; a load including one or more light emitting diodes, the load connected in series with the first reference voltage node; a second reference voltage node; a first load pathway and a second load pathway, connected in parallel between the load and the second reference voltage node; wherein the first load pathway includes a first inductor and a first transistor, connected in series; and wherein a second load pathway includes a second inductor and a second transistor, connected in series; and one or more controllers, configured to control the first transistor and the second transistor.

Abstract: The invention relates to an optoelectronic circuit intended to receive, between a first node and a second node, a variable voltage, the optoelectronic circuit including: a plurality of light-emitting diodes series-assembled between the first node and a third node; a first current limitation/regulation circuit assembled between the third node and the second node; a switching circuit coupling the third node to at least certain light-emitting diodes of the plurality of light-emitting diodes; a capacitor including first and second plates; a first diode having its cathode connected to the second plate and having its anode coupled to the second node; and a second diode having its anode connected to the second plate and having its cathode coupled to the third node or to a second current limitation/regulation circuit.

Abstract: A power supply device includes converters, a command circuit, and a setter. The converters correspond to loads. The command circuit controls the converters. The setter sets a magnitude of an output of at least one target converter of the converters in accordance with an output characteristic representing a relationship between an input voltage of the at least one target converter and an output limit value which is an upper limit value of the output from the at least one target converter. The output characteristic is a characteristic that the output limit value decreases as the input voltage lowers when the input voltage is lower than a threshold. The setter varies the threshold of the output characteristic in accordance with an operation status of the converters and sets the magnitude of the output from the at least one target converter in accordance with the output characteristic whose threshold has been varied.

Abstract: A light system is disclosed. The light system includes a light emitting diode (LED) and a shunt transistor having a current path connected to the LED. A ramp generator circuit generates a ramp voltage. An amplifier has a first input terminal connected to the LED, a second input terminal coupled to receive the ramp voltage, and an output terminal connected to a control terminal of the shunt transistor.

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.