Abstract: A DC-DC converter has a pulse width control circuit producing a sequence of pulses, with an on time, an off time and a switching frequency. The on time as well as the switching frequency are both varied in dependence on a dimming setting.

Abstract: An AC direct drive lamp including a leakage current protection circuit includes an input stage configured to receive external power, a rectification circuit configured to rectify the external power received from the input stage, a control module electrically connected to the output stage of the rectification circuit and configured to sense and control the state of at least one of the rectification circuit, a switch module, and a light source, the switch module connected between the input stage and the control module in a feedback form and configured to switch on/off depending on a predetermined condition, and the light source electrically connected to the control module and configured to radiate light when power is applied.

Abstract: A circuit for driving a light source includes a power converter coupled between a power source and the light source, and a controller coupled to the power converter. The power converter receives power from the power source and provides a regulated power to the light source. The controller receives a conduction status signal indicating a conduction state of a dimmer coupled between the power source and the power converter, and adjusts the brightness of the light source based on the conduction status signal. The controller also receives an operation indicating signal indicative of operation of an ON/OFF switch coupled to the dimmer, and adjusts color temperature of the light source based on the operation indicating signal.

Abstract: A lighting application is provided that includes an LED assembly including a serial connection of two or more LED units, each LED unit including one or more LEDs, each LED unit being provided with a controllable switch for substantially short-circuiting the LED unit. The lighting application further includes a control unit for controlling a drive unit and arranged to receive a signal representing a voltage level of the supply voltage, and control the switches in accordance with the signal. An LED driver is provided that enables to operate a TRIAC based dimmer at an optimal holding current and an LED driver including a capacitor as a switchable buffer.

Abstract: A light string includes a plurality of lights and a plurality of non-polarity capacitor corresponding to the lights; wherein, the lights are electrically connected in series and to be powered by an AC power supply; each of the non-polarity capacitor is connected in parallel to a corresponding one of the lights. When the light string is powered on, the non-polarity capacitor is charged and absorbs the surge current which may occur. Thus, the voltage dropped on each light rises slowly and the lights are safe. The non-polarity capacitor also performs power compensation and electrical connection.

Abstract: An LED lighting device includes an auxiliary power supply that supplies power to a control circuit of the LED lighting device that receives an input from a terminal of a light-emitting diode (LED) string of the lighting device that has a substantially lower voltage than the line voltage to which the lighting device is connected. The terminal may be within the LED string, or may be an end of the string. A linear regulator may be operated from the voltage drop across a number of the LEDs in the string so that the energy wasted by the auxiliary power supply is minimized. In other designs, the auxiliary power supply may be intermittently connected in series with the LED string only when needed. The intermittent connection can be used to forward bias a portion of the LED string when the voltage supplied to the LED string is low, increasing overall brightness.

Abstract: The invention relates to a modular LED-light comprising a first module (1) to which an input voltage (9), preferably an AC-supply voltage, is guided, said first module comprising a second sub-module (B), preferably an insulating unit, a DC voltage separating the supply voltage by a galvanic separation being provided on the outlet of said insulating unit, and a control unit (G). Said LED light also comprises a second module (2), preferably a light management module, comprising an additional sub-module (C) which is fed by the DC-initial voltage of the first module (1), preferably a clocked constant flow source which is controlled by a control unit (E) of the second module (2), and an LED-module (F) which comprises at least one LED path (8) and which is supplied by the additional sub-module (C).

Abstract: A light-emitting diode (LED) driving circuit configured to drive LED units includes a rectification circuit unit to receive an alternating current (AC) power voltage and rectify the AC power voltage to output a unidirectional ripple voltage, a pulse-width modulation (PWM) signal generation unit to generate PWM decision signals. The PWM signal generation unit is configured to sequentially drive the LEDs according to the PWM decision signals.

Abstract: A linear LED driver comprises a transistor having an input terminal coupled to a LED. When the transistor is turned on, the LED is lighted. The linear LED driver further includes a protection circuit for judging whether an instant high voltage variation occurs or not according to at least one of the voltages of a control terminal and an output terminal of the transistor so as to achieve a protection function.

Abstract: A power supply and method of controlling power supplied to a light source are disclosed. The power supply includes a dimming-control voltage generator configured to generate a dimming-control voltage based on first and second adjustment values; a dimming controller configured to output a dimming control signal for controlling analog dimming and pulse width modulation (PWM) dimming of a light source based on the dimming-control voltage; and a driver configured to control the analog dimming and the PWM dimming of the light source based on the dimming control signal.

Abstract: A timing circuit may be enabled when a static signal disables communication through a communications bus, the timing circuit producing a threshold level after being enabled for a predetermined time period, and a switch controlled by the timing circuit is configured to disconnect the static signal when the timing circuit produces the threshold level. A static signal may be used to enable a timing circuit upon the static signal disabling communication through a communications bus, and communication may be allowed through the communication bus by disconnecting the static signal using a switch controlled by the timing circuit, after the timing circuit has been enabled for a predetermined period of time.

Abstract: The present invention relates to a driver device and a corresponding driving method for driving a load (22), in particular an LED unit, said driver device comprising power input terminals (51, 52) for receiving a periodic supply voltage from an external power supply potentially including a dimmer for dimming said periodic supply voltage, power output terminals (53, 54) for providing a drive voltage and/or drive current for driving a load (22), a power stage (70a, 70b, 70c, 70d) coupled between the power input terminals and the power output terminals for controlling an input current received from said power input terminals to draw a high power from said external power supply in a first mode or to draw a low or no power from said external power supply in a second mode, said high power being higher than the power required for driving said load and said low power being lower than the power required for driving said load, wherein said power stage controls said input current to be in the second mode only for a perc

Abstract: An electric driver circuit for driving a light-emitting diode may be operated in a regulation operation mode to generate an output voltage to drive a predefined current through the light-emitting diode. The electric driver circuit is operated in a start-up operation mode before the regulation operation mode. The operation of the electric driver circuit in the start-up operation mode enables that a coil current generated in an inductor can be completely discharged before starting the regulation operation mode.

Abstract: Disclosed is a backlight driving apparatus. The backlight driving apparatus includes a light source configured to include at least one LED, a DC-DC converter configured to generate a driving voltage according to a turn-on of a switching element and supply the driving voltage to the light source, a feedback circuit configured to generate a feedback voltage corresponding to a voltage level of the driving voltage supplied from light source, a duty controller connected to the light source, and configured to control a turn-on period of the LED according to an LED duty signal corresponding to a backlight dimming signal, and a switching controller configured to generate a PWM signal for controlling the turn-on of the switching element according to the feedback signal, generate a switching control signal corresponding to the PWM signal according to the LED duty signal, and selectively control the turn-on of the switching element.

Abstract: The LED backlight source includes a boost circuit, a current control module, a voltage detection circuit. The boost circuit is configured for boosting an input voltage to an operation voltage needed by a LED string. The current control module connects to a negative end of the LED string to adjust an operation current of the LED string. The voltage detection circuit is configured for detecting whether the input voltage has been decreased, and for providing a control signals to a backlight driving control circuit upon determining the input voltage has been decreased. The backlight driving control circuit is configured for providing first square-wave signals to the boost circuit for boosting the voltage, for providing second square-wave signals to the current control module for adjusting a current, and for decreasing an input current upon receiving the control signals from the voltage detection circuit.

Abstract: In a first aspect, the invention provides an LED converter, comprising: a resonant converter with a switching regulator, preferably a clocked half-bridge converter, a galvanic barrier, the primary side of which being supplied by the switching regulator and the secondary side of which being arranged for providing directly or indirectly power to terminals for connecting one or more LEDs, a control circuit on the primary side of the galvanic barrier of the resonant converter, a sensing means on the secondary side of the galvanic barrier sensing a secondary side electric parameter indicative of an LED load, when connected to said terminals, a feedback path from the sensing means to the control circuit adapted to feedback the secondary side electric parameter from the secondary side of the galvanic barrier to the primary side of the galvanic barrier, wherein in case no LED string is connected to the LED converter, the control unit is adapted to cyclically control a switching frequency of switching regulator switch

Abstract: A method for mitigating visual fluctuation of light output at low pulse width modulation levels is disclosed. The method comprises at least the step of comparing the percent change of a previously applied input voltage value to the pulse width modulation output.

Abstract: An inductive power transfer system comprises a primary side unit (1) and a secondary side unit (6) with a non-conductive barrier (5) therebetween, the primary side unit having a power supply (2), a transmission coil (4) and a controller (12). The secondary side unit has a receiver coil (7), a controller (8) and a load (9). The secondary side controller (8) is configured to detect the voltage in the receiver coil (7) and to transmit to the primary side controller (12) a control signal requesting an increase or decrease in the power transmitted from the primary side according to whether the voltage in the receiver coil (7) is above or below a predetermined value.

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: Disclosed are various embodiments of low cost high quality LED (Light Emitting Diode) retrofit lamp devices capable of operating in a wide range of power and to supersede conventional lighting devices such as incandescent, halogen, sodium or fluorescent lamps. The disclosed embodiments include various LED lamp retrofit apparatuses that maximize the electro-mechanical-optical compatibility of seven interactive systems, such as: LEDs, LED Panel, Supply Adaptor, Housing, Lens/diffuser Shield, In/Out Electrical Wiring an LED driver. LED lamp retrofit apparatuses include incandescent, halogen, fluorescent, and sodium lamps.

Abstract: An illumination module includes a plurality of Light Emitting Diodes (LEDs) located in different zones to preferentially illuminate different color converting surfaces. The flux emitted from LEDs located in different zones may be independently controlled by selectively routing current from a single current source to different strings of LEDs in the different zones. In this manner, changes in the CCT of light emitted from LED based illumination module may be achieved.

Abstract: A straight tube LED lamp according to one aspect of the present invention includes: a first LED array including first LED elements connected in series; a second LED array that includes second LED elements connected in series, and emits light having a different emission color from an emission color of the first LED array; a FET switch provided in a path through which current flows to the second LED array; and a constant power output circuit that outputs power without changing a total value of the power, wherein the number of the first LED elements connected in series is greater than the number of the second LED elements connected in series, a total forward voltage of the first LED array is greater than a total forward voltage of the second LED array, and the first LED elements are in alignment with the second LED elements.

Abstract: An apparatus comprises red, green and blue LED strings each having a corresponding switching circuit. Each LED string is divided into a plurality of LED segments. The three LED strings are connected in parallel or in series. Each LED string may be connected in series with a respective current source or share a common current source. A controller controls each switching circuit so that the number of LED segments connected in series in the red, green or blue LED string can be respectively controlled according to a color setting signal and the voltage level of an input voltage. A first control method is provided for controlling the apparatus having a constant input voltage and a second control method is provided for controlling the apparatus having a periodically time-varying input voltage.

Abstract: A circuit (400) is described herein for controlling dimming of a lamp (112), the circuit comprising a switching circuit (422) configured to provide a chopped portion of an input AC power signal, a resettable inverting integrator circuit (426) configured to integrate the chopped portion of the input AC power signal such that a rise time of an output of the resettable inverting integrator circuit is proportional to a positive amplitude of the chopped portion of the input AC power signal and a fall time of the output of the resettable integrator is proportional to a negative amplitude of the chopped portion, such that an energy provided to the lamp based on the output of the resettable inverting integrator circuit is substantially equivalent from cycle-to-cycle of said input AC power signal regardless of a change in amplitude of the input AC power signal from cycle-to-cycle.

Abstract: A current supply is coupled to a light source. The current supply is further coupled to a controller. The controller is configured to provide a stochastic control signal to the current supply, wherein the stochastic control signal controls a light intensity output of the light source.

Abstract: Power lighting control methods and systems for solid state lighting are disclosed. For example, a power control system includes a transformer that includes a primary coil configured to receive a first voltage based on an output of a switching circuit, a secondary coil configured to generate a first current based on the first voltage to power a solid-state load, and a bleeder coil coupled to a bleeder switch, and a control module that causes the bleeder switch to turn on incrementally during a dimming event over M power cycles, where M is a positive integer, so as to eliminate or reduce a current step in the first current provided to the solid state load.

Abstract: A current driving circuit is connected to an LED terminal LEDi, and generates an intermittent driving current ILEDi that corresponds to a dimming pulse signal PWMi. An error amplifier generates a feedback voltage VFB that corresponds to the difference between a detection voltage VLEDi and a predetermined reference voltage VREF. A pulse modulator generates a pulse signal having a duty ratio that corresponds to the feedback voltage VFB. A fault detection comparator COMP_OPENi generates a fault detection signal OPEN_DET which is asserted when the detection voltage VLEDi is lower than a predetermined threshold voltage VOPEN—DET. A forced turn-off circuit instructs the current driving circuit to suspend the generation of the driving current ILEDi during a predetermined period after a switching power supply starts to operate. The fault detection circuit detects whether or not the fault detection signal OPEN_DETi has been asserted in a predetermined period.

Abstract: There are provided a light emitting diode (LED) driving apparatus and an LED lighting apparatus, in which a common detection resistor detecting a current flowing in each LED is used. According to exemplary embodiments of the present disclosure, manufacturing costs and a circuit area may be reduced by commonly using a common detection resistor detecting a current flowing in each of the LEDs.

Abstract: An LED controller circuit for use in an LED drive circuit in which a coil current control scheme is used to deliver power to an LED arrangement from a phase cut dimmer. The controller circuit includes means for determining, based on an analysis/signal processing of the on-time of the transistor, the dimmer characteristics, including the on state and off states of the ac dimmed voltage signal. This avoids the need for the controller circuit to process the dimmer output.

Abstract: System and method for regulating a power converter. The system includes a first signal processing component configured to receive at least a sensed signal and generate a first signal. The sensed signal is associated with a primary current flowing through a primary winding coupled to a secondary winding for a power converter. Additionally, the system includes a second signal processing component configured to generate a second signal, an integrator component configured to receive the first signal and the second signal and generate a third signal, and a comparator configured to process information associated with the third signal and the sensed signal and generate a comparison signal based on at least information associated with the third signal and the sensed signal.

Abstract: A system for controlling motor switching in a sensorless BLDC having a stator with three stator windings and a permanent magnet rotor. The system includes a controller unit comprising a control signal generator, a memory device, a processing unit, a signal acquisition device, and an analog-to-digital converter. A power stage controlled by the controller unit has a plurality of switches and drives two windings of the three stator windings with a pulse width modulation signal and leaves one stator of the three stator windings undriven. The processing unit acquires a demodulated measured voltage on the undriven winding. The processing unit calculates a threshold at which the power stage will change which two windings of the three stator windings are driven when the demodulated measured voltage surpasses the threshold.

Abstract: A method includes providing an input signal identifying a desired brightness for one or more LEDs to first and second parallel control paths. The method also includes generating a digital modulation control signal using the first control path, generating a current control signal using the second control path, and driving the one or more LEDs using the control signals. The method further includes performing compensation in at least one of the control paths to compensate for an increased efficiency of the one or more LEDs. Generating the control signals could include (i) adjusting the digital modulation control signal while maintaining the current control signal at a substantially constant value for a range of lower LED brightness values and (ii) adjusting the current control signal while maintaining the digital modulation control signal at a maximum value or within a range of maximum values for a range of higher LED brightness values.

Abstract: Some embodiments include a LED-based light module. The LED-based light module can include a memory to store a color mixing plan; a regulator that receives a variable output voltage from a power supply; a voltage measurement component, coupled in parallel to the regulator and the power supply, configured to measure a voltage level of the variable output voltage; a logic component; and a driver circuit. The logic component can be configured to determine driving current profiles for LEDs in the LED-based light module to dim a light output of the LEDs based on the voltage level. The driver circuit can drive the LEDs according to the driving current profiles by drawing power from the power supply (e.g., through the regulator).

Abstract: Method and means for driving one or more LEDs. The method includes turning a power switch on to provide current through an inductor and the power switch, measuring voltseconds of the LEDs at a cycle time, comparing the measured voltseconds to a reference signal at an end of the cycle time, generating a signed discrete logical signal based on a difference between the measured voltseconds and the reference signal, and generating a control signal using the signed discrete logical signal to regulate a peak current through the power switch by keeping the cycle time voltseconds substantially constant. The reference signal may be proportional to a set average LED voltage.

Abstract: The present invention provides an LED (Light-Emitting Diode) driving control circuit for controlling a converting circuit to transform an input power source into an output voltage for driving an LED module. The LED module has a plurality of LED strings. The LED driving control circuit includes a voltage detecting circuit and a feedback control circuit. The voltage detecting circuit has a plurality of detection circuits, and each detection circuit is coupled to a terminal of the corresponding LED string to determine whether a voltage of the terminal is higher or lower than a preset value. The voltage detecting circuit generates a feedback signal according to the determination results. The feedback control circuit controls the converting circuit to modulate the output voltage according to the feedback signal.

Abstract: A backlight device includes an input line connected to an anode of a light source unit; an output line connected to a cathode of the light source unit; a resistance line connected between the output line and a ground and disposed in a pattern having a predetermined width and length to have a predetermined resistance; a sensing line connected to the output line; and a controller for measuring a balance voltage of the output line through the sensing line and controls an amount of current supplied to the input line based on the balance voltage, in which when a reference current is supplied to the input line, the balance voltage of the output line becomes a predetermined reference voltage due to the predetermined resistance.

Abstract: If a dimming ratio of a light source unit is higher than a first ratio, an ON width of a first switching device is increased with a second switching device kept off when the dimming ratio is increased, and also the ON width of the first switching device is decreased with the second switching device kept off when the dimming ratio is decreased. If a dimming ratio of the light source unit is lower than the first ratio, the ON width of the second switching device is regulated with the ON width of the first switching device held at a lower limit.

Abstract: An illumination system includes: a signal receiver device configured to, in response to a coupling signal, generate a receiver-side signal frame including a control code portion based on control information of the coupling signal; a code extracting unit operable to extract the control code portion from the receiver-side signal frame; and a current providing unit operable to provide a driving current through a light emitting component according to the control code portion extracted from the code extracting unit. The driving current has a magnitude dependent on the extracted control code portion.

Abstract: Provided is a display device, including: a plurality of pixels; a scan driver connected to a plurality of scanning lines connected to the plurality of pixels; and a gate signal generator configured to determine a level of a gate-on voltage according to ambient temperature and to supply the gate-on voltage to the scan driver, wherein the gate signal generator is further configured to apply a hysteresis characteristic to a thermistor voltage to vary according to the ambient temperature.

Abstract: An efficient, cost effective power driver for OLED panels is configured with a small BOM without compromising the display quality. The power driver adopts only one Inverting Buck-Boost Converter (IBBC) to regulate the necessary output voltage for the OLED panel load. The output voltage to drive the OLED panel load is supplied by the IBBC and the positive input of the OLED panel is tied into the input power supply of VIN directly without any switch. A DC-DC converter is provided to generate a reference ground and drive the associated control circuits. The input DC voltage VIN is utilized as a reference voltage for both the IBBC and the DC-DC converter.

Abstract: The LED lighting device of the present invention includes: a power supply circuit connected between a light source including a light emitting diode and a power source and including a series circuit of a switching device and an inductor; an inductor current detector configured to provide a measurement value indicative of an inductor current flowing through the inductor; a drive circuit configured to turn on the switching device at a predetermined period and turn off the switching device when the measurement value is equal to a first threshold or more; a load current detector configured to measure a load current flowing through the light source; and a protection device configured to, when the load current measured is equal to a second threshold or more, perform a protection operation of changing, to reduce the load current, a circuit constant of a power supply path in which the load current flows.

Abstract: A method for powering two circuits in a portable light that are connected by a single conductive chassis so that each of the two circuits is able to have time shared access to a power source.

Abstract: A light emitting diode (LED) backlight driving circuit includes a power supply, a constant current driving unit that drives LED light bars, a switching unit coupled to the power supply, and M light units that are connected with each other in parallel. Each of the light units comprises at least two LED light bars that are connected with each other in parallel, and an input end of each of the LED light bars is coupled to the switching unit. The constant current driving unit includes a plurality of dimming channels coupled to an output end of the LED light bars, and each of the dimming channels is connected with M LED light bars. The M LED light bars connected with a same dimming channel are arranged in different light units, one LED light bar is coupled to one dimming channel. The power supply is only coupled to one light unit through the switching unit when the LED backlight driving circuit is in operation, and M is a positive integer.

Abstract: A microcontroller-based multifunctional electronic switch uses a detection circuit design to convert external motion signals into message carrying sensing signals readable to the microcontroller. Based on the time length of sensing signals and the format of the sensing signals received in a preset instant period of time the microcontroller through the operation of its software program codes written in the OTPROM is able to recognize the working modes chosen by the external signal generating user and thereby selecting the appropriate loops of subroutine for execution. The system and method of the present invention may simultaneously be applicable to detection circuit design using infrared ray sensor, electrostatic induction sensor, conduction based touch sensor or push button sensor for performing multifunction such as controlling the on/off switch, the illumination power and the color temperature within the capacity of a single lighting device or an electrical appliance.

Abstract: An LED driving device includes a first converter, a second converter, and a control circuit. The first converter generates a first voltage from received alternating current (AC) power. The second converter receives the first voltage and drives a plurality of LEDs based on the received first voltage. The control circuit sets a reference voltage level based on a level of the first voltage generated by the first converter, and controls the level of the first voltage by comparing a level of the AC power and a level of the reference voltage.

Abstract: A light adjusting system for use with sport simulation equipment and a method of adjusting a state of operation of at least one light source used with golf simulation equipment is provided. The light adjusting system comprises a data interface, a light controller, an operations processor, and a storage device. The data interface is in communication with the sport simulation equipment. The light controller is in communication with at least one light source. The operations processor is in communication with the data interface and the light controller. The storage device is in data communication with the operations processor. The storage device includes at least one lighting profile. In response to communication between the sport simulation equipment and the data interface, the operations processor accesses the at least one lighting profile on the storage device and adjusts a state of operation of the at least one light source using the light controller.

Abstract: It is provided an LED lighting device calibratable to 0 to 100% of wide range about a chromaticity and luminance of a illumination light by a simple configuration, and a driving method for the LED lighting device. The LED lighting device is provided with a first light-emitting unit and a second light-emitting unit differing a color temperature mutually, and a control circuit for executing a cyclic light/quench control of the first light-emitting unit and the second light-emitting unit, and for executing a light control of the first light-emitting unit and the second light-emitting unit by a PNM (Pulse Number Modulation) control in a fixed cycle so as to have a lighting period Ton for lighting/quenching the first light-emitting unit and the second light-emitting unit complementarily, and a quenching period Toff for quenching both the first light-emitting unit and the second light-emitting unit.

Abstract: There is provided a light emitting diode driving apparatus, including: a power supplying unit converting input power into driving power according to a control and supplying the converted driving power to a light emitting diode channel; a driving unit controlling current flowing in the light emitting diode channel according to a pulse width modulation (PWM) dimming signal from the outside; and a controlling unit comparing a reference level set by a duty of the PWM dimming signal with a detection voltage level of the light emitting diode channel and controlling a power converting operation of the power supplying unit according to the comparison result.

Abstract: An LED drive circuit comprises a power supply unit, a first LED lamp string, a first voltage control unit, a second LED lamp string and a first power transfer unit. The power supply unit outputs a drive power to drive the first LED lamp string. The first voltage control unit gets the drive power and stabilizes and provides the voltage to the first LED lamp string. The first voltage control unit includes a power switch where the drive power generates a power loss. The second LED lamp string and first power transfer unit are coupled in series with the first voltage control unit so that the power loss is transferred and output to drive the second LED lamp string. Thus loss of the drive power is reduced and lighting efficiency of the LED improves.

Abstract: A lighting apparatus includes a power supply unit and a control unit configured to control the power supply unit. The control unit determines, at a time of activation of the lighting apparatus, a first color temperature of the load at an initial stage of lighting based on a command value. Thereafter, the control unit controls the power supply unit such that the light quantity and the color temperature of the load change according to a second output characteristic during a period in which the color temperature of the load changes from the first color temperature to a second color temperature. The second color temperature is a color temperature, in the first output characteristic, corresponding to the command value. A correspondence relationship between a plurality of light quantities and a plurality of color temperatures defined by the second output characteristic is different from that of the first output characteristic.