Abstract: A backlight driving circuit is disclosed. The backlight driving circuit includes a boost circuit, a constant-current driving chip, a detecting module and a LED string coupled with the boost circuit. The boost circuit boosts an input voltage and then provides the boosted voltage to the LED string. The detecting module receives and calculates external PWM optical signals to obtain a duty-cycle ratio of the PWM optical signals, and compares the duty-cycle ratio of the external PWM optical signals with a predetermined threshold to determine if control signals have to be generated for the constant-current driving chip such that the constant-current driving chip controls the current passing through the LED string. The backlight driving circuit can operate normally even when the duty-cycle ratio of the PWM optical signals is very small. In addition, a liquid crystal display includes the above backlight driving circuit is also disclosed.

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: A light emitting element driving device, which flashing-drive a plurality of light emitting element arrays connected in parallel by switching elements connected in series with each of the plurality of light emitting element arrays, the light emitting element driving device including: a current detection unit configured to detect respective currents flowing through each of the plurality of light emitting element arrays as currents of the light emitting element arrays; a selection unit configured to select the smallest current of the light emitting element arrays of the detected currents obtained by the current detection unit; and an output voltage control unit configured to control output voltage supplied to the plurality of light emitting element arrays so that the current of the light emitting element arrays selected by the selection unit becomes a preset reference current value.

Abstract: A LED driving circuit drives a plurality of LED (Light Emitting Diode) groups, has a common voltage that is changed according to an input voltage of the plurality of LED groups, and includes a common node, a plurality of phase switches arranged between the output terminals of the plurality of LED groups and the common node, and a plurality of phase switch control units that form current flows among a corresponding LED group, a corresponding phase switch, and the common node in phase sections of the input voltage based on the common voltage and a corresponding reference voltage, the input voltage having a time-variable phase. Accordingly, the LED driving circuit can correct a power factor without using an inductor or a capacitor.

Abstract: An electronic ballast for operating at least one first cascade of LEDs may include an input for coupling to an AC supply voltage, a rectifier that is coupled to the input, wherein the rectifier has an output having a first and a second output connection, a first unit that includes the first cascade of LEDs, wherein the first unit is coupled to the first output connection of the rectifier, a series circuit including an inphase regulator and a shunt resistor, wherein the series circuit is coupled between the first unit and the second output connection of the rectifier, a setpoint value prescribing apparatus for the inphase regulator having an output that is coupled thereto, wherein the setpoint value prescribing apparatus provides a first setpoint value element at its output, and a second setpoint value element—superimposed on the first setpoint value element—for the inphase regulator.

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, where m is a positive number equal to or less than n. The driver circuit also includes a plurality of current regulating circuits, each of the current regulating circuits being coupled to the downstream end of a corresponding group at one end and coupled to the ground at the other end and including a sensor amplifier and a cascode having first and second transistors, each sensor amplifier being coupled to a different voltage source for providing a different reference voltage thereto.

Abstract: A distributed system for driving strings of series-connected LEDs for backlighting, display and lighting applications includes multiple intelligent satellite LED driver ICs connected to a an interface IC via serial bus. The interface IC translates information obtained from a host microcontroller into instructions for the satellite LED driver ICs pertaining to such parameters as duty factor, current levels, phase delay and fault settings. Fault conditions in the LED driver ICs can be transmitted back to, the interface IC. An analog current sense feedback system which also links the LED driver ICs determines the supply voltage for the LED strings.

Abstract: A transformer isolated LED lighting circuit supplies current from a secondary-side storage capacitor to one or more LED strings in conformity with one or more dimming values. The dimming values are communicated through the transformer by patterns or codes provided in pulses of a power converter circuit that charges the storage capacitor from the primary side of the transformer, or alternatively by a special modulated signal provided in addition to the switching pulses.

Abstract: Systems and methods are provided for regulating a string current flowing through a string of one or more light emitting diodes. A system controller includes a first controller terminal, a second controller terminal and a third controller terminal. The first controller terminal is coupled to a base terminal of a bipolar junction transistor, the bipolar junction transistor further including an emitter terminal and a collector terminal, the collector terminal being connected to the string of one or more light emitting diodes. The second controller terminal is coupled to the emitter terminal of the bipolar junction transistor and to a first resistor terminal of a resistor associated with a resistance. The third controller terminal is coupled to a second resistor terminal of the resistor. In addition, the system controller is configured to receive a reference voltage, receive an emitter voltage, and output a base current.

Abstract: The present document relates to providing power for driving SSL devices. A power converter converts a varying input voltage to supply an output voltage to a SSL device in series with a current source. The power converter comprises one or more capacitors; a plurality of switches to couple the capacitors in a plurality of configurations. A control unit operates the power converter in a plurality of operational modes providing a corresponding plurality of different conversion ratios between the input/output voltages. The operational modes comprise a first phase and a second phase, during which the capacitors are differently arranged. The control unit controls the switches to alternate between the phases at a commutation cycle rate. The control unit sets the operational mode based on the varying input voltage.

Abstract: A distributed system for driving strings of series-connected LEDs for backlighting, display and lighting applications includes multiple intelligent satellite LED driver ICs connected to a an interface IC via serial bus. The interface IC translates information obtained from a host microcontroller into instructions for the satellite LED driver ICs pertaining to such parameters as duty factor, current levels, phase delay and fault settings. Fault conditions in the LED driver ICs can be transmitted back to the interface IC. An analog current sense feedback system which also links the LED driver ICs determines the supply voltage for the LED strings.

Abstract: LED devices are provided that include LED chips on LED chip carriers. The LED device can in turn be housed in a package, such as a small-outline transistor (SOT) package or a radial LED device package. A single LED device or a serial connection of a plurality of such LED devices can be operated directly from an AC (line) voltage or a rectified version thereof. In some example embodiments, switching circuitry is integrated into the LED chip carrier for controlling current flow through the LED(s) in response to, for example, a brightness regulating control signal. Numerous example embodiments of the monolithic LED devices are provided, including manufacturing processes as well as various example packages for such LED devices.

Abstract: The present disclosure relates to a technology or improving the efficiency of light emitting diode (LED) elements and extending the lifespan thereof, significantly reducing cost and improving efficiency of a power supply while supplying sufficient LED driving power to an LED lamp module without the use of an output-side electrolytic capacitor need in a converter, and extending the lifespan of the converter. Consequently, the present disclosure relates to a technology of reducing product cost and maintenance cost and extending the lifespan of an LED lighting device.

Abstract: A LAM/ICM assembly comprises an integrated control module (ICM) and an LED array member (LAM). The ICM includes interconnect through which power from outside the assembly is received. In a first novel aspect, active circuitry is embedded in the ICM. In one example, the circuitry monitors LED operation, controls and supplies power to the LEDs, and communicates information into and out of the assembly. In a second novel aspect, a lighting system comprises an AC-to-DC converter and a LAM/ICM assembly. The AC-to-DC converter outputs a substantially constant current or voltage. The magnitude of the current or voltage is adjusted by a signal output from the LAM/ICM. In a third novel aspect, the ICM includes a built-in switching DC-to-DC converter. An AC-to-DC power supply supplies a roughly regulated supply voltage. The switching converter within the LAM/ICM receives the roughly regulated voltage and supplies a regulated LED drive current to its LEDs.

Abstract: The invention is provided with an LED driving device and the control method. The driving device includes power converter, microprocessor and LED circuit. Wherein the power converter includes impulse transformer and switch control circuit. Primary winding at input side of the impulse transformer connects with rectifier filter circuit by the switch control circuit. Secondary winding at output side and auxiliary winding connect with power end of the microprocessor by constant voltage control switch. Output end of the microprocessor connects with LED circuit. The LED driving device and the control method provided by this invention collects on/off signal of mechanical lamp by using switch control circuit. Light is adjusted by LED circuit driven by the microprocessor, and thus heat elimination effect is improved, power consumption is lowered and brightness is enhanced.

Abstract: The present invention discloses an LED backlight system and a display device. The LED backlight system includes an LED display module and an LED backlight control circuit. The LED display module includes LED string. The LED backlight control circuit includes a current module, a comparison unit, a control switch unit, and an impedance unit wherein, an input terminal of the comparison unit obtains a voltage at a negative terminal of the LED string, and when the voltage at the negative terminal is greater than a preset threshold voltage, the comparison unit controls the control switch unit to turn on such that the impedance unit connects in parallel with the current module so as to decrease the voltage at the negative terminal. Through above way, the present invention can prevent the unstability of the circuit loop in order to prevent the flicker phenomenon of the backlight system.

Abstract: A distributed system for driving strings of series-connected LEDs for backlighting, display and lighting applications includes multiple intelligent satellite LED driver ICs connected to a an interface IC via serial bus. The interface IC translates information obtained from a host microcontroller into instructions for the satellite LED driver ICs pertaining to such parameters as duty factor, current levels, phase delay and fault settings. Fault conditions in the LED driver ICs can be transmitted back to the interface IC. An analog current sense feedback system which also links the LED driver ICs determines the supply voltage for the LED strings.

Abstract: Circuits and methods prevent ringing of white LED drivers by adding a high voltage coil switch (CS) circuit, a high voltage edge detector circuit, and a boot strap circuit. The coil switch (CS) circuit to short the coil of a boost converter, when the current in it reaches zero during DCM, comprises a series of 2 identical HV enhancement NMOS with bulk switch system. An Edge Detector circuit senses the fast falling edge of an LX node. A Boost Strap circuit lifts the gate of coil switch circuit above the battery voltage level and turns on the coil switch. A Boost Strap (BS) system lifts the gate of CS above the VBAT level and turns on CS, wherein minimum current is required to minimize impact on efficiency.

Abstract: A protection circuit of a backlight driver circuit includes a backlight driver circuit. The backlight driver circuit includes a backlight driver integrated circuit (IC), and the backlight driver IC includes a protection pin that controls the backlight driver IC to enter a protection mode. The backlight driver circuit further includes a protection circuit, and the protection circuit includes a monitoring unit that monitors a temperature of the backlight driver circuit. When the temperature of the backlight driver circuit exceeds a preset temperature, the monitoring unit sends the protection signal to the protection pin to control the backlight driver IC to enter the protection mode.

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, where m is a positive number equal to or less than n. The driver circuit also includes a plurality of current regulating circuits, each of the current regulating circuits being coupled to the downstream end of a corresponding group at one end and coupled to the ground at the other end and including a sensor amplifier and a cascode having first and second transistors, each sensor amplifier being coupled to a different voltage source for providing a different reference voltage thereto.

Abstract: A luminaire according to one embodiment includes a DC power supply circuit, a switching power supply, and a lighting load. The DC power supply circuit converts an AC voltage controlled in phase to a DC voltage. The switching power supply is connected to the DC power supply circuit, and is controlled so that an input current becomes a constant current. The lighting load is connected as a load circuit of the switching power supply.

Abstract: The invention provides an LED converter for operating a load comprising at least one LED series with at least one LED, preferably with multiple LEDs, wherein the LED converter on the primary side comprises a resonant converter supplied with a direct current voltage. Said converter has a half-bridge constructed of two reciprocally clocked switches and providing a supply voltage for the LED series through a serial/parallel resonance circuit connected to the midpoint of said bridge. The LED converter has a control unit that is arranged for adjusting the clocking frequency of the half bridge.

Abstract: In a conventional example, even if a duty cycle of the burst dimming is changed during an OFF-period of a switching element, current flowing to an LED is maintained constant. On the other hand, in the present embodiment, an accumulated value of ON-periods of a switching element is increased or decreased so as to be linked to a minimum variation width for a duty cycle (a dimming level) of a dimming signal, regardless of a timing of when the duty cycle is changed. Therefore, a lighting system (an LED drive device) according to the present embodiment can change smoothly a light output of a solid-state light-emitting element (a light source) with respect to a change in a duty cycle of the burst dimming while preventing the switching frequency from increasing.

Abstract: A driver for driving an LED backlight source is disclosed. The driver includes a boost converter for boosting inputted DC voltage and outputting boosted DC voltage to an LED series circuit having LEDs connected and a resistor in series, a feedback circuit for feeding back voltage across the resistor to a backlight driving circuit, and a control switch controlled by output of the backlight driving circuit depending on feedback voltage of the voltage across the resistor for keeping current flowing through the LED series circuit in a constant current. The driver drives the LED series circuit with a constant current, thereby prolonging lifetime of each LED of the LED series circuit. Furthermore, since a time period which the current flowing through the LED series circuit approaches to constant value is shorter, the driver has advantages over lower power consumption, faster response time and better operating efficiency.

Abstract: LED light source suitable for use with a phase cut dimmer (III), comprising •input terminals (K1, K2) for connection to an AC supply voltage, •a rectifier (I) coupled to the input terminals, 108 a series arrangement comprising N LEDs (LL1, LL2, LL3) coupled to the rectifier, •control circuitry (EX) for sequentially activating (deactivating) the LEDs as the supply voltage increases (decreases), wherein the control circuitry comprises: •N controllable current regulators, each regulator being coupled between the cathode of a LED and ground and comprising a transistor and one impedance in series, •a global current control circuit (X) coupled to the control electrodes of said transistors and comprising circuitry for adjusting the voltage at said control electrodes in dependency of the phase angle, •a series arrangement of a switch (S) and a capacitor (C1) coupled- to the rectifier and •means (VIII) for rendering said switch conductive in case the AC supply voltage drops below a reference value.

Abstract: A driving circuit includes a plurality of light-emitting units, a plurality of switches, and a voltage generating module. The light-emitting units are coupled with each other in series and are driven with an input voltage varying according to a frequency. Each switch has a preset voltage and an activation voltage and includes a light-emitting end, a control end, and a setting end. The light-emitting ends are coupled with the light-emitting units, and the setting ends of the switches are coupled with each other. The voltage generating module includes a plurality of control units and provides a plurality of control voltages to the switches, and each switch is driven to be activated or to be deactivated according to a relation of the preset voltage and a difference between the control voltage and the activation voltage when the input voltage drives the light-emitting units, the switches, and the control units.

Abstract: Solid state lighting systems are disclosed for providing uniform brightness of LEDs serially connected in a string. In some embodiments, the LEDs can be powered directly from the mains such that no switch-mode power supply or the output storage elements associated therewith are needed. In some such cases, a linear regulator and switches can be used to control the current through the LEDs to provide uniform brightness. Other embodiments can be used with a switch-mode based driver topology and/or storage elements coupled in parallel with clusters of the LEDs. In any such cases, control logic (e.g., microcontroller or other suitable controller) can be used to control the switches accordingly to provide uniform brightness, and in some cases, to mitigate the implications of having no SMPS output storage element. In some embodiments, the switching pattern provided by the control logic is random, although other switching patterns can be used.

Abstract: An electrical circuit for driving a light emitting diode (LED) string is described. The electrical circuit includes a first LED string having one or more color LED strings. A first current control transistor is coupled in series with the first LED string. A color bypass transistor may couple in parallel to one of the one or more color LED strings. A second LED string may also be coupled to the first LED string at an anode terminal of both LED strings. The second LED string may be coupled in parallel with a string bypass transistor and in series with a second current control transistor. Connection interfaces to control terminals of the first current control transistor, the color bypass transistor, the second current control transistor, and the string bypass transistor enable a control device to operate these transistors in linear mode to drive the LED strings.

Abstract: The present invention provides a controller used in a TRIAC dimmer compatible LED driver and method thereof. The controller comprises a dimming signal generator, a dimming signal processor and a switch control circuit. The dimming signal generator receives an AC chopped voltage from a TRIAC dimmer and generates a dimming signal with regulated duty cycle in accordance with the AC chopped voltage. The dimming signal processor is coupled to the dimming signal generator and generates a processed dimming signal in accordance with the dimming signal. The duty cycle of the processed dimming signal is a sum of a predetermined duty cycle and the duty cycle of the dimming signal. Based on the processed dimming signal and a feedback signal indicative of the current flowing through LED, the switch control circuit generates a control signal to control at least one switch in a switching converter.

Abstract: An LED driver system including an input receiving a rectified AC conductive angle modulated voltage on a rectified node, a converter, a low-pass filter, and AC detector, and a driver network. The converter is coupled to the rectified node and includes a power switching device coupled to a switching node, in which the power switching device is controlled to convert the rectified AC conductive angle modulated voltage to an output voltage and output current. The low-pass filter is configured to filter voltage of the switching node to provide a filtered voltage. The AC detector receives the filtered voltage and provides a current sense signal indicative thereof. The driver network controls duty cycle of the power switching device based on the current sense signal.

Abstract: A user interface for implementing a configurable light timer controlling a light is disclosed. The user interface comprises an input portion for receiving timing characterization data, the input portion adapted to receive a portable memory device storing the timing characterization data; an actuator portion enabling a user to enter a current time on the timer; and a display responsive to the actuator portion to indicate the current time. A method of implementing a configurable light timer is also disclosed.

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, where m is a positive number equal to or less than n. The driver circuit also includes a plurality of current regulating circuits, each of the current regulating circuits being coupled to the downstream end of a corresponding group at one end and coupled to the ground at the other end and including a sensor amplifier and a cascode having first and second transistors, each sensor amplifier being coupled to a different voltage source for providing a different reference voltage thereto.

Abstract: An LED bulb is described, comprising LEDs within a shell and a driver circuit to operate the LEDs at a plurality of brightness levels. The driver circuit comprises first and second inputs to receive AC, a neutral input, a converter circuit, first and second rectifier circuits, a detector circuit, and a processing circuit. The first rectifier circuit is connected to the first and neutral inputs and rectifies the AC received. The second rectifier circuit is connected to the second and neutral inputs and rectifies the AC received. The detector circuit is connected to the first and second rectifier circuits. The processing circuit has a first and a second processor input, and is connected to the detector circuit. The processing circuit produces a chop signal with a duty cycle based on whether the first or second input is hot. The converter circuit powers the LEDs based on the chop signal.

Abstract: A constant power drive for light emitting diodes, such that there is automatic compensation for variation in forward voltage of the LED, both in a single unit with temperature, and also due to unit-to-unit variations.

Abstract: A lighting device for a semiconductor light emitting element includes a series circuit of two switching elements which are alternately turned on, the series circuit being connected to a direct current (DC) input power source and a reactance circuit connected between a connection node of the two switching elements and one end of the DC input power source through a capacitor, an output of the reactance circuit being supplied to the semiconductor light emitting element through a rectifier circuit. A dimming operation of the semiconductor light emitting element is performed by varying a ratio of ON periods of the two switching elements.

Abstract: A LED driving system comprising: an input port to receive an input signal; a switch node to provide a switching signal; an energy storage component coupled between the input port and the switch node; a main switch coupled between the switch node and ground; n output lines coupled in parallel, and each output line having a first and second terminals, and wherein the first terminal is coupled to the switch node, and the second terminal is coupled the reference ground, and wherein each output line having an output switch, a diode and a LED string coupled in series between the first and second terminals, and wherein each output line having a capacitor coupled in parallel with the LED string; and a controller providing a control signal to the main switch and providing corresponding n control signals to the corresponding n output switches in the corresponding n output lines.

Abstract: A Light Emitting Diode (LED) driver circuit for driving an LED string has a switch-mode power supply coupled to the LED string. A control circuit is provided and has a first terminal coupled to a pulse width modulated input and a second terminal coupled to the switch mode power supply. A disconnect switch is coupled to a third terminal of the control circuit and the LED string.

Abstract: A power converter is disclosed that includes an active valley fill (AVF) capacitor that is actively switched to provide current to a load during a portion of an alternating current (AC) input cycle. The current supplied to the load includes some current supplied by the AC input and some current supplied by the AVF capacitor. Circuitry is configured to regulate the amount of current flowing through the load, including controlling the amount of current supplied by the AVF capacitor. The duty cycle on the AVF capacitor can be adjusted to shape the AC input current waveform.

Abstract: A light emitting diode (LED) backlight driving circuit includes a rectifier module, a voltage reduction module coupled to the rectifier module, and an LED lightbar coupled to the voltage reduction module. A city voltage is inputted to the rectifier module, and a pulse-width modulation (PWM) controls the voltage reduction module.

Abstract: The present invention provides an LED backlight drive circuit, which includes a first power supply module, an electrical inductor, a rectifier diode, a MOS transistor, an electrolytic capacitor, an LED light string, a voltage division module, a voltage comparator, a second power supply module, and an LED constant-current drive chip. The LED backlight drive circuit is arranged to include a voltage comparator in an external circuit of the LED constant-current drive chip to detect output voltage of the drive circuit so that high voltage, the voltage comparator is caused to supply a low voltage level to forcibly pull down a PWM dimming signal or an ENA enabling signal of the LED constant-current drive chip to achieve an over-voltage protection function and also enable removal of over-voltage protection module from a conventional LED constant-current drive chip.

Abstract: A power supply circuit having at least two conversion stages wherein the first conversion stage includes input terminals for connection to an ac or dc supply, an electronic converter with constant output current characteristics and output terminals for connection to at least one second conversion stages. Each second conversion stage includes input terminals to receive a substantially constant current input from a first conversion stage, current multiplier circuit and output terminals for connection to a load. The electric converter of the first conversion stage is a high frequency resonance converter having a series parallel resonant converter with an inductance connected in series with a capacitor. The output terminals for connection to the second conversion stage are connected across the capacitor and the inductance. Circuits are particularly suitable for lighting applications, for controlling the large number of LEDs in LED display panels or in backlighting for televisions and LCD displays.

Abstract: A solid-state light-emitting element drive device includes a switching regulator and a control circuit. The switching regulator includes a series circuit of a switching element and an inductor, a regenerative element configured to allow a regenerative current to flow therethrough from the inductor when the switching element is turned off, and output terminals configured so that a solid-state light-emitting element is connected therebetween. The control circuit is configured to control a switching operation of the switching element of the switching regulator. The control circuit is configured to suppress an output power of the switching regulator if a parameter obtained from at least one of an ON-period and an OFF-period of the switching element is out of a prescribed range.

Abstract: A backlight driving circuit includes a power module and a constant current driver chip. The power module includes a first controllable switch. An adjustable load is connected between the first controllable switch and a ground terminal of the backlight driving circuit, and the adjustable load includes a switching module controlling a resistance value of the adjustable load, a switching mode signal of the backlight driving circuit is sent to a control end of the switching module. A first end of the adjustable load that is connected to the first controllable switch is coupled to an over current protection (OCP) port of the constant current driver chip.

Abstract: The present invention discloses a backlight driving board for driving a backlight source, comprising a microprocessor and a constant current driver chip. The microprocessor receives a display mode switching signal and a synchronization signal from a liquid crystal driving board, and generating a first pulse width modulation signal corresponding to the backlight source according to the display mode switching signal and the synchronization signal. The constant current driver chip controls an operation state of the backlight source according to the first pulse width modulation signal.

Abstract: An apparatus and method allow end users to interactively create complex lighting patterns by remote control. Applications include decorative lighting, landscape lighting, signage, or advertising platforms. A lighting control system can be equipped with sensors that can receive remote control signals from a variety of different sources, and route the control signals to modulate receptacles coupled to different lighting circuits, thereby independently controlling multiple light arrays to achieve separate light patterns, or to coordinate different lighting effects. Interactive remote control can be provided via a mobile computing device such as a smart phone running a customized program. In one embodiment, the remote control device communicates selections to a Bluetooth®-equipped speaker to produce sound-controlled lighting effects.

Abstract: An apparatus and method allow end users to interactively create complex lighting patterns by remote control. Applications include decorative lighting, landscape lighting, signage, or advertising platforms. A lighting control system can be equipped with sensors that can receive remote control signals from a variety of different sources, and route the control signals to modulate receptacles coupled to different lighting circuits, thereby independently controlling multiple light arrays to achieve separate light patterns, or to coordinate different lighting effects. The control signals can independently energize localized groups of lamps to provide enhanced lighting effects, while using significantly less wire material. Interactive remote control can be provided via a mobile computing device such as a smart phone running a customized program. In one embodiment, the remote control device communicates selections to a Bluetooth®-equipped speaker to produce sound-controlled lighting effects.

Abstract: Pulse switching controller for the LED lighting of the LED drive module for lamps in automobile applications provided with light sources having LED diodes and a drive module for the LED function and excitation, where the drive module (3) comprises at minimum one resistance regulator (38) working in pulse switching duty, which is connected by its input to the last cathode of the corresponding branch (33) of LED diodes and by its output to the input electrode of a switching element (37), which is connected by its output electrode to ground, while the controlling electrode of the switching element (37) is connected to the output of a pulse generator (36) with a set duty cycle in dependence on the input voltage, which is connected both by a sensor input to the input voltage from the input circuit (31) and by an external input (35).

Abstract: Pulse width modulation is provided for controlling a resonant power converter, particularly for dimming of light emitting diode arrays without loss of efficiency. Dynamic oscillation due to the beginning of a pulse width modulated pulse burst is limited by shortening of the first and/or last pulse of a pulse bust such that the first pulse of a subsequent pulse burst close to or to connect with a full load steady-state voltage/current trajectory of the power converter. Pulse shortening made be made substantially exact to virtually eliminate dynamic oscillation but substantial reduction in dynamic oscillation is provided if inexact or even performed randomly.

Abstract: An LED drive circuit, which comprises a transformer, an MOS tube, a power regulating resistor, a direct current isolation circuit, a rectifying circuit, and a voltage control circuit; when the voltage of the control terminal of the voltage control circuit is higher than the threshold voltage of the MOS tube, the MOS tube is on, a current from an external power supply flows through the first winding of the transformer, the MOS tube and the power regulating resistor successively; when the voltage of the power regulating resistor is close to the voltage of the reference terminal of the voltage control circuit, the MOS tube is cut off, the second winding of the transformer charges the capacitor of the MOS tube via the direct current isolation circuit, the rectifying circuit is on, and the first winding of the transformer supplies power to the LED load via the rectifying circuit.

Abstract: A light-emitting-diode (LED) driving apparatus including an AC-DC power conversion stage, a balance circuit and a pulse-width-modulation (PWM) control unit is provided. In the present invention, the LED driving apparatus balances currents flowing through all LED strings by using the balance circuit such that a purpose of current matching is achieved accordingly. In addition, the LED driving apparatus may control the PWM control unit according to an equation between an independent DC output voltage generated by the AC-DC power conversion stage and a control voltage provided by the balance circuit without adopting any boost converter so as to indirectly change a DC output voltage used for directly driving all LED strings and generated by the AC-DC power conversion stage. In this way, the purpose of low cost and high efficiency can be achieved accordingly.