Abstract: A lighting device includes light emitting element groups (HSB) including a light emitting element group (HS2) that emits light when being applied with a voltage (VH2), and a light emitting element group (HS12) that emits light when being applied with a voltage (VH12) higher than VH2, the light emitting element groups (HSB) emitting light when being applied with a voltage equal to or higher than a voltage (VHa); an IC1 including a light emission control unit (HC1) arranged to cause light emission of a light emitting element group (HS) if a voltage (Vk) is higher than VHa, and to stop the light emission if Vk is lower than the same; and an IC2 including a light emission control unit (HC2) arranged to cause light emission of a group (HSa) if Vk is higher than VHa, and to turn off the group (HSa) if Vk is lower than the same.

Abstract: A lighting circuit and a method of operating a lighting circuit are described. A rectifier 14 has an input for an alternating voltage V. At least a first and a second LED assembly 20, 22 are connected to be supplied with electrical power from the rectifier 14. The first LED assembly 20 is electrically connected to a first output 26 of the rectifier 14 and electrically connected in series with an input 36 of a switching converter circuit. The second LED assembly 22 is electrically connected to an output 48 of the switching converter circuit 44. A control assembly 30 is connected to a tap 46 in the series connection for controlling operation of the first LED assembly 20.

Abstract: A lighting device includes a rectifier circuit, a driver circuit and a shunt circuit. The driver circuit is configured to apply respective voltage components contained in a pulsating voltage from the rectifier circuit every period of the pulsating voltage across part and all of solid light sources in response to the pulsating voltage and respective ON voltages of light source circuits including the part and all of the solid light sources. The shunt circuit is electrically connected in parallel with a light source circuit having a lowest ON voltage of the light source circuits, and configured to set a value of an output current from the rectifier circuit to a value proportional to a value of the pulsating voltage while the pulsating voltage is less than the lowest ON voltage.

Abstract: A light output control device includes a switching device, multiple signal input ports, a signal selection circuit, and a control circuit. The switching device is to be electrically connected between a direct-current power supply and a light source circuit. The light source circuit includes a semiconductor light emitting element. The multiple signal input ports respectively correspond to multiple kinds of light output control signals. The signal selection circuit selects, when receiving two or more light output control signals indicating different light output levels through the multiple signal input ports, a light output control signal indicating a lowest (or highest) light output level, from the two or more light output control signals. The control circuit performs switching control of the switching device with a duty cycle corresponding to the lowest (or highest) light output level indicated by the light output control signal selected by the signal selecting circuit.

Abstract: A light emitting device with low voltage-endurance components includes a light emitting diode string, M first control circuits, a detection unit and a current control circuit. The light emitting diode string includes M first light emitting diodes connected in series. Each first control circuit includes a first switch. One end of the light emitting string is coupled to a node of an input voltage. The first switch is connected to its related first light emitting diode in parallel and can enable a bypass current path. The detection unit detects the potential of the input voltage to produce a current detection signal. The current control circuit is coupled to the M-th one of the M first control circuits and the detection unit and controls the M-th one of the M first control circuits to selectively enable the bypass current path according to the current detection signal.

Abstract: A system, in some embodiments, comprises: multiple light emitting diode (LED) strings configurable in series or in parallel depending on a supply voltage provided in the system; and multiple current regulators, a different one of the multiple current regulators coupled to each of the multiple LED strings and configured to regulate current passing through a respective LED string, wherein at least one of the multiple current regulators is bypassed when the multiple LED strings are configured in series.

Abstract: An LED driving apparatus according to an exemplary embodiment of the present inventive concept may include a rectifier circuit rectifying alternating current (AC) power to generate driving power for operating a plurality of LED arrays; a controller integrated circuit (IC) including a plurality of internal switches connected to respective output terminals of the plurality of LED arrays and controlling a path of a current flowing in the plurality of LED arrays by adjusting operations of the plurality of internal switches according to a magnitude of the driving power; and a current controlling circuit connected to the output terminal of at least one of the plurality of LED arrays and controlling a current flowing in the at least one LED array.

Abstract: The described invention provides a method of and circuitry for driving three or more groups of light emitting diodes (LEDs) using time division multiplexing, whereby a periodic signal is divided among groups of LEDs, each with a different color or color temperature. The LEDs may be driven to produce colors along a desired path of values. Other qualities of light besides color or color temperature may be similarly controlled along a path of values. In some implementations, the system may receive an oscillating signal, which may be used as a periodic signal for comparison with the control signal, and one or more offset voltages, each of which may be combined with the oscillating signal to provide a second oscillating signal. The control signal may be compared to both of the oscillating signals to determine if a particular LED group may be powered.

Abstract: Various embodiments may relate to a method for determining life expectancy information of an LED module with a plurality of LEDs. The method includes detecting of forward biases of the LED module at instants of time which lie less than 100 ms apart from each other, comparing a currently detected forward bias with one or more earlier detected forward biases, in order to detect a voltage jump which reaches a minimum initial inverse voltage within a predetermined jump duration, wherein the minimum initial inverse voltage is at least 60 mV and the predetermined jump duration is less than 100 ms long, and determining life expectancy information based on one or more detected voltage jumps.

Abstract: An backlight adjustment circuit (20), configured to adjust luminance of light emitted by one light-emitting diode (LED) string (11) of a LED module (10), the LED string (11) includes a plurality of LEDs (D) and a current control resistor (R). The backlight adjustment circuit (20) includes a light sensing circuit (21) for sensing the luminance of one corresponding LED string (11) and producing a corresponding light sensing signal value; a comparison unit (22) for comparing the light sensing signal value with a preset reference value, and producing a first signal when comparing the light sensing signal value is less than the preset reference value, else producing a second signal; and an adjustment unit (23) for decreasing the luminance of the LED string (11) when receiving the first signal and increasing the luminance of the LED string (11) when receiving the second signal.

Abstract: Disclosed is a lighting apparatus which includes LEDs and reduces flicker. The lighting apparatus may secure a charge voltage by performing a charge operation using a current corresponding to a rectified voltage equal to or more than a preset level, and compensate for the rectified voltage provided to a lighting unit including LED groups by performing a discharge operation for the charge voltage in response to the rectified voltage less than the preset level, thereby reducing flicker.

Abstract: The disclosure provides a driving apparatus and a method for driving a semiconductor light-emitting device assembly. The apparatus includes: a driving unit configured to drive the semiconductor light-emitting device assembly; and a cycle by cycle control unit. The cycle by cycle control unit may include: a sampling circuit configured to sample a current instantaneous value of the driving unit or the semiconductor light-emitting device assembly; and an adjusting circuit configured to adjust an output of the driving unit when the current instantaneous value sampled by the sampling circuit is larger than or equal to a preset reference value. The driving apparatus and method for driving the semiconductor light-emitting device assembly may effectively reduce an inrush current on the light-emitting devices and have a lower cost.

Abstract: A light emitting diode (LED) lighting system includes a first string of first LEDs emitting light having a first color. A second string of second LEDs emits light having a second color and connected in series with the first string of first LEDs; A first switch and a second switch are connected in series. A regulator module is configured to modulate the first switch and the second switch to provide a desired current ratio. The desired current ratio corresponds to a ratio of a first current through the first string of first LEDs to a second current through the second string of second LEDs.

Abstract: The present invention relates to a device for driving LEDs and, more specifically, to an AC-direct drive-type LED driving device, capable of sequentially driving LEDs connected in series in reverse order by starting with an LED located at the end until a certain size of power is supplied, and sequentially driving the LEDs connected in series in order if the certain size of power is supplied, rather than measuring the size of a rectified power and sequentially driving the LEDs connected in series based on the measured size of the power; thereby equalizing the power consumption of all the LEDs connected in series to thereby equalize the life span of the LEDs regardless of the serial connection order of the LEDs and unifying the brightness of all the LEDs connected in series.

Abstract: A light emission driving device includes an output voltage supply unit arranged to generate an output voltage from an input voltage so as to supply the output voltage to a load, a determination unit arranged to determine whether or not a ground fault due to abnormality may have occurred on the basis of an anode voltage of the load, and a signal output unit arranged to externally output a signal indicating that a ground fault due to abnormality may have occurred when the determination unit determines that a ground fault due to abnormality may have occurred. The output voltage supply unit does not perform generation stop of the output voltage by a trigger of determination by the determination unit that a ground fault due to abnormality may have occurred.

Abstract: A dual color series-wired LED light string formed of a plurality of sockets, each of which receives an LED housing containing a pair of LEDs connected in anti-parallel configuration. Each LED socket includes a protective resistive component which is electrically connected across each pair of anti-parallel LEDs of the respective LED housing to protect each LED of the pair from reverse voltage breakdown damage in the event of a failure of the other LED in the housing. The protective resistive component also further serves as a shunt to electrically bypass a failed LED to keep the remaining LEDs in the light string fully illuminated.

Abstract: A light emitting diode (LED) backlight driving circuit includes a power supply, an LED lightbar coupled to the power supply, and a constant current driving chip coupled to a control end of the power supply and coupled to a cathode of the LED lightbar. The constant current driving chip includes an adjusting dimming unit coupled to the cathode of the LED lightbar, and the adjusting dimming unit adjusts an external pulse-width modulation (PWM) dimming signal. A controllable switch unit is connected in series between an output end of the power supply and the constant current driving chip, and logical operation of the controllable switch unit is relative to logical operation of the adjusting dimming unit. The controllable switch unit turns off when the adjusting dimming unit turns off or before the adjusting dimming unit turns off, and the controllable switch unit turns on when the adjusting dimming unit turns on or after the adjusting dimming unit turns on.

Abstract: A universal LED tube includes a LED light bar, a power conversion apparatus, and a safety switch apparatus. The power conversion apparatus converts an external power source to provide the required power for supplying the LED light bar. The safety switch apparatus is connected to the LED light bar and the power conversion apparatus. The LED light bar is driven to emit light by the external power source after a switch module of the safety switch apparatus is certainly turned on.

Abstract: The present invention discloses a light emitting device driver circuit and a driving method of a light emitting device circuit. The light emitting device driver circuit is for driving a light emitting device circuit with plural light emitting devices connected in series. The light emitting device driver circuit determines a number of the conductive light emitting devices according to a rectified input voltage. The light emitting device driver circuit includes: a switch module, a current source circuit, and a total harmonic distortion (THD) compensation circuit. The THD compensation circuit generates an adjustment current according to the rectified input voltage. The current source circuit provides a light emitting device current to the light emitting device circuit according to the adjustment current, such that the THD is reduced.

Abstract: A power supply is provided. The power supply includes at least one light emission unit, a power source, an openness detection circuit, and a feedback control unit. The at least one light emission unit includes a plurality of serially connected LEDs. The power source supplies a DC voltage to the light emission unit. The openness detection circuit varies a reference potential with a voltage which is detected from both ends of at least one of the LEDs in the light emission unit. The feedback control unit regulates an output current of the power source according to the reference potential of the openness detection circuit.

Abstract: A light generating device (1) is provided with at least a voltage input (21) adapted for receiving a variable voltage, at least three LED circuits (10), coupled with said voltage input (21), wherein each LED circuit (10) comprises a LED unit (14) and controllable current regulator (15) to control the current through said LED circuit (10). The light generating device (1) further comprises a controllable switch matrix (30) comprising a plurality of switches (25, 26, 27), said switch matrix (30) is configured to operate in at least three different switching modes and a controller (50), connected at least with said switch matrix (30), configured to determine said variable operating voltage and to control the switching mode of said switch matrix (30) in dependence of the determined operating voltage.

Abstract: An organic EL device that efficiently extracts light includes an organic EL element formed by laminating a first electrode layer, functional layer, and second electrode layer on a substrate and a sealing member sealing the organic EL element. The organic EL device has a first electrode communicating part electrically connected to the first electrode layer at one side of the substrate and a second electrode communicating part electrically connected to the second electrode layer at the other side of the substrate. The organic EL device has first cross grooves crossing the organic EL element from the second electrode layer located at the one side to the second electrode layer that is located at the other side. The first cross groove is formed by removing the first electrode layer, functional layer, and second electrode layer. The sealing member and the substrate are connected outside of the first cross grooves.

Abstract: The present invention discloses a light emitting device driver circuit. The light emitting device driver circuit drives a light emitting device circuit. The light emitting device circuit includes plural light emitting devices connected in series and a diode circuit, wherein the plural light emitting devices are divided to plural groups. The light emitting device driver circuit includes: a first switch circuit, a second switch circuit, a current source circuit, and a control circuit. The first switch circuit includes plural first switches connected in parallel to the corresponding groups respectively. The second switch circuit includes plural second switches coupled to a forward end and a reverse end of the diode circuit respectively, wherein the second switch circuit determines whether to conduct the forward end or the reverse end to the current source circuit according to the voltages of the forward end and the reverse end.

Abstract: The purpose of the present invention is to provide an LED drive circuit that is capable of ameliorating insufficient lighting and improving power utilization efficiency.

Abstract: An LED driving apparatus controls a light emitting unit including first to k-th LED arrays, a rectifier for rectifying an AC signal, and first to (k?1)-th driving units respectively corresponding to the first to (k?1)-th LED arrays. Each driving unit includes an input terminal connected to a first terminal of the LED array, a sensing terminal connected to a second terminal of the LED array, an output terminal connected to a next driving unit, a transistor between the input terminal and the sensing terminal, and a sensing resistor between the sensing terminal and the output terminal. The rectified signal or voltage is applied to the first driving unit.

Abstract: This LED lighting device makes a maximum current to minimum current flowing in an LED a target proportion regardless of LED driving circuit performance and without erroneous operation. An LED lighting device (1) is provided with: an LED circuit (5) that includes at least one LED (1-5); a bypass means (6a) inserted in parallel with the LEDs (1-5); and an LED driving circuit (4) that supplies current by duty control to the LEDs (1-5) and the bypass means (6a). When a prescribed minimum current flows in the LED circuit (5), the LED driving circuit (4) supplies current in which a portion of current flowing in the bypass means (6a) is added to this minimum current and carries out control of the added current by a switching element (TR1) connected in series to the LED circuit (5) and the bypass means (6a).

Abstract: Embodiments of the invention include a luminaire that includes a plurality of different light engines. Light engines having different light distributions can be included in a single luminaire and a subset of the light engines selectively driven to dynamically change the light distribution of the luminaire. In this way, a single luminaire is capable of illuminating an area with a variety of different light distributions.

Abstract: Disclosed are novel AC-powered LED light engines for Solid State Lighting (SSL) able to achieve a high PF and a low THD without a traditional PFC. Getting rid of bulky, and costly magnetic components, short-life electrolytic capacitor, and EMI-causing fast switching, the disclosed AC-powered LED light engines ushers in a cost-effective, and energy-efficient LED driver design while eliminating the short-life electrolytic capacitor in an LED driver and reducing the Total Cost of Ownership (TOC). Thanks to no bulky components, the disclosed AC-powered LED light engines in a discrete or an integrated circuit form could be applied to the increasingly popular Driver-on-Board (DoB) design. Aside from being TRIAC-dimmable via legacy phase-cut dimmers, the disclosed LED light engines could also be made PWM-, analog-, or rheostat-dimmable with the incorporation of an appropriate dimming circuit to modulate the average LED current, adding more flexibility and versatility to dimming applications.

Abstract: A microcomputer of a light source control device specifies an LED belonging to LEDs and subjected to a short-circuit failure based on a result of determination by a short-circuit failure detecting circuit and current amounts sensed by current sensing circuits respectively. The microcomputer makes corresponding one of switching elements interrupt supply of a current to the specified LED. The microcomputer makes a constant current circuit supply an LED not specified with a current not exceeding a current responsive to the number of such LEDs not specified.

Abstract: An illumination device (1) comprises: input terminals (2) for coupling to AC mains; a LED string (10) connected in series with the input terminals; a rectifier (30), having input terminals connected in series with the LED string; a controllable voltage source (40), having input terminals coupled to the rectifier output terminals; a series arrangement of at least one auxiliary LED (51) and a second ballast resistor (52) connected to the output terminals of the controllable voltage source. The voltage source comprises: a series arrangement of an adjustable first resistor (46) and a second resistor (47) connected in parallel to the input terminals; a tuneable Zener diode (49) connected in parallel to the output terminals, having a control input terminal (48) connected to the node between the two resistors; wherein positive output terminal is connected to positive input terminal and negative output terminal is connected to negative input terminal.

Abstract: A semiconductor component and a method for manufacturing the semiconductor component, wherein the semiconductor component includes one or more transient voltage suppression structures. In an embodiment, the semiconductor component may include an over-voltage detection circuit, an over-current detection circuit, an over-temperature detection circuit, an ESD protection circuit, or combinations of these circuits.

Abstract: A converting controller comprises a power pin, a ground pin, at least one input pin, at least one output pin, at least one set pin and a failure generating circuit. The power pin is adapted to be coupled with a power source to receive electric power for operation, and the ground pin is adapted to be grounded. The input pin is adapted to receive a corresponding input signal and the output pin is used to output a corresponding output signal. The set pin is adapted to set a corresponding operating parameter of the converting controller. The failure generating circuit is coupled with and uses one of the input pin and the set pin as a protection output pin. The failure generating circuit modulates the level of the protection output pin to be a protection logic level when the converting controller is under a protection state.

Abstract: A lighting system and protection means are disclosed. In particular, a Zener diode with pre-selected characteristics is used in parallel with an LED such that current will continue to flow through the circuit in case of LED failure. This adaptation in turn may be used in a series string combination.

Abstract: A driver circuit is configured for connection to a power source and includes a plurality of light emitting diodes (LEDs) having at least one performance characteristic that varies according to different performance categories ranging between higher performance and lower performance. The driver circuit also includes a plurality of LED sections each populated with at least one LED of a different one of the different performance categories. Circuitry is coupled to the LED sections and configured to activate and deactivate the LED sections based on LED performance.

Abstract: A driver circuit for driving light emitting diodes (LEDs). The driver circuit includes a string of LEDs divided into n groups, the n groups of LEDs being electrically connected to each other in series, a downstream end of group m?1 being electrically connected to the upstream end of group m. The driver circuit also includes a power source coupled to an upstream end of group 1. The driver circuit further includes a plurality of current regulating circuits, where each current regulating circuit is coupled to the downstream end of a corresponding group at one end and coupled to a ground at another end and includes a sensor amplifier and a cascode having two transistors. The driver circuit also includes a phase control logic for sending a signal to each of the current regulating circuits to thereby control a current flow through each of the current regulating circuits.

Abstract: An LED element with a color light enhancement function is a two-terminal element for receiving a driving current to emit light and includes at least one blue LED chip, at least one red LED chip and a three-way compensator. The three-way compensator intercepts a driving current passing through the blue LED chip depending on a proportion value according to a change of working temperature and adjusts the amount of current flowing into the red LED chip. If the working temperature exceeds a default value, an input terminal of the three-way compensator is triggered to intercept the driving current and generate and output a set current to the red LED chip to compensate an attenuation of the red LED chip caused by high temperature. The LED element will not be changed its intensity after a prolonged period of usage.

Abstract: A load driving apparatus relating to light-emitting-diodes (LEDs) is provided. In the invention, a compensation voltage on a compensation pin (CMP) of a control chip would not be changed in response to (or with) the variation (i.e. enabling and disabling) of a pulse-width-modulation (PWM) signal for dimming. In other words, the compensation voltage on the compensation pin (CMP) of the control chip would be maintained in unchanging regardless of whether the PWM signal for dimming is enabled or disabled. Therefore, an LED string at the current switching transient does not have the generation of over-shoot current.

Abstract: When a pulsating current is applied to an LED string included in an LED lighting device, and the number of LEDs caused to light up is changed, the LED lighting device is in efficient, since there are LEDs lighting up for a long period of time and LEDs lighting up only for a short period of time. The LED string includes LED string 407 that lights up for a long period of time and LED string 408 that lights up only for a short period of time within a period of the pulsating current. The element size of the LED 102 included in LED string 407 is different from the element size of LED 203 string 408. Thus, the amount of light emission per unit area LED string 407 may be equal to the amount of light emission per unit area LED string 408.

Abstract: The present invention provides a protection circuit with low energy-consumption and a driving circuit thereof. The protection circuit includes a detection circuit and a switch circuit. The switch circuit is disposed between a power supply circuit and a peripheral step-down shunt. The detection circuit and the switch circuit are connected for controlling. The switch circuit includes a PNP triode or a P MOS transistor connected between the power supply circuit and the peripheral step-down shunt. A base of the PNP triode or the P MOS transistor is connected to a drain of another N MOS transistor through a resistor, and a gate of the N MOS transistor is connected to a status pin of the detection circuit. The present invention solves drawbacks of existent input voltage after the circuit entering a protection state causing unnecessary energy-consumption in peripheral small-signal circuit and voltage-dividing resistors.

Abstract: An LED driving device with open circuit protection and color temperature and brightness adjustment is applied in a lamp to drive LEDs which are divided into strings, and at least one string is formed by connecting blue light diodes in series, and the remaining strings are formed by connecting yellow light LEDs in series, and at least one of the yellow light strings is connected to the blue light string in parallel and then connected to the remaining strings in series to form a node. The LED driving device employs a switch to conduct the blue or yellow light string to change the color temperature of the emitted light of the lamp, and a power input pin of a control chip is electrically coupled to the node. If there is an open circuit caused by an abnormality of the LEDs, the operation will be stopped to provide protection.

Abstract: An illuminated light socket is provided for powering a light bulb in a typical light string system. The illuminated socket contains its own lighting element, separate and distinct from the light bulb. The lighting element remains off when the light bulb is inserted into the socket and is illuminating properly. The lighting element illuminates when either the bulb is removed from the socket or the bulb is not illuminating correctly. The illuminated light element provides a visually perceptible warning, on the socket itself, that the associated light bulb is either absent or defective. Alternatively, a collar performing the same function is provided such that the collar may be mounted to existing light sockets. The illuminated sockets and housings may accommodate light bulbs of any technology, e.g. incandescent, LED (single or multiple color), or electroluminescent. The socket lighting element itself is preferably a low power LED or electroluminescent light.

Abstract: A three-terminal LED and drive circuit thereof. The three-terminal LED (1) has an anode, a cathode and a gate. The three-terminal LED (1) includes a LED group (3) formed by connecting at least one LED in series and a gate circuit (2), the first end (21) of the gate circuit (2) and the anode of the LED group (3) are connected with the anode of the three-terminal LED (1), the second end (22) of the gate circuit (2) and the cathode of the LED group (3) are connected with the cathode of the three-terminal LED (1), the third end (23) of the gate circuit (2) is connected with the gate of the three-terminal LED (1).

Abstract: In various embodiments, an illumination system includes multiple light-emitting strings that are selectively activated or deactivated to regulate an overall output of the array.

Abstract: There is provided a light emitting diode (LED) driving apparatus configured such that a waveform of current input to an LED follows a sine wave, the LED driving apparatus including, a switching unit switching an LED unit having a plurality of LEDs receiving rectified power and emitting light, a driving control unit controlling the switching of the switching unit according to a voltage level of the rectified power, a current limiting unit limiting current flowing in the LED unit, and an adjusting unit adjusting current limitation of the current limiting unit according to the voltage level of the rectified power.

Abstract: A light generating device (1) is provided with at least a voltage input (21) adapted for receiving a variable voltage, at least three LED circuits (10), coupled with said voltage input (21), wherein each LED circuit (10) comprises a LED unit (14) and controllable current regulator (15) to control the current through said LED circuit (10). The light generating device (1) further comprises a controllable switch matrix (30) comprising a plurality of switches (25, 26, 27), said switch matrix (30) is configured to operate in at least three different switching modes and a controller (50), connected at least with said switch matrix (30), configured to determine said variable operating voltage and to control the switching mode of said switch matrix (30) in dependence of the determined operating voltage.

Abstract: A LED lamp that includes a LED lamp controller with delayed startup after a fault condition is detected. The type of the fault condition is used in determining a length of the startup delay, such as a number of power cycles during which the LED lamp controller is prevented from completing its configuration. Examples of different types of fault conditions include faults in a supply voltage or faults in a feedback voltage to the LED lamp controller. Fault type information can also be stored in circuitry that retains data and is not reset across the power cycles.

Abstract: A device for driving a multi-channel light-emitting diode, includes a power supply unit for supplying power supplied from the outside; a light-emitting diode block, which is connected to a (+) terminal of the power supply unit and includes one or more light-emitting diode groups, each including at least one light-emitting diode; a current commutation unit, which is connected to a cathode of the light-emitting diode block and commutates a current flowing through the light-emitting diode groups; a reference voltage unit, which is electrically connected to the current commutation unit and provides a reference voltage to the current commutation unit; and a current driving unit for receiving power from the power supply unit, driving the light-emitting diode block through the current commutation unit, and determining a driving current flowing through the light-emitting diode groups.

Abstract: A circuit is disclosed for determining which of a multiplicity of LED strings in an illumination system has a fault. A group of circuits determines the maximum, minimum, midpoint between maximum and minimum, and average voltage of the group of LED string voltages in use, and examines the statistical properties of the LED string voltages. Comparators are used to find the strings which have the highest and lowest operating voltages, and to compare the midpoint and average voltages to determine whether the highest or lowest voltage string is responsible for causing a fault in the illumination system operation. Memory means are used to keep the said determined string turned off to prevent faulty operation.

Abstract: A circuit is disclosed for driving a plurality of LED strings from an AC supply and arranged to, in use, drive current through a series arrangement of a plurality N of the LED strings when the AC voltage is sufficient to drive the plurality N of the LED strings: the circuit comprising a first current source configured to be switchably connected to a one end of said series arrangement of N LED strings; a series combination of a second current source and a heat dissipater, wherein the series combination of the second current source and the heat dissipater is arranged in parallel with the first current source; and a current balancer for balancing the current through the first current source and the second current source. A driver for such a circuit is also disclosed.

Abstract: Self-identifying solid-state transducer (SST) modules and associated systems and methods are disclosed herein. In several embodiments, for example, an SST system can include a driver and at least one SST module electrically coupled to the driver. Each SST module can include an SST and a sense resistor. The sense resistors of each SST module can have at least substantially similar resistance values. The SSTs of the SST modules can be coupled in parallel across an SST channel to the driver, and the sense resistors of the SST modules can be coupled in parallel across a sense channel to the driver. The driver can be configured to measure a sense resistance across the sense resistors and deliver a current across the SSTs based on the sense resistance.