Abstract: The invention provides a driver circuit, an LED lighting tube and a method for providing a controlled DC output power. An open loop control is used for controlling the DC output power in the case that a voltage of an AC input power is in a first voltage range. A closed loop control is used for controlling the DC output power in the case that the voltage of the AC input power is in a second voltage range.

Abstract: Aspects of the subject technology relate to display circuitry such as backlight control circuitry for operating light-emitting diodes (LEDs). The backlight control circuitry may include a pulse-width-modulation (PWM) transistor and a current regulation transistor coupled in series with at least one LED. The current regulation transistor may have a gate terminal that receives a feedback-controlled gate voltage. The backlight control circuitry may include a gate clamp circuit coupled to the gate terminal of the current regulation transistor that clamps the gate voltage during a portion of a PWM on pulse.

Abstract: A light source device capable of preventing luminance from being decreased, a driving method of the light source device and a display device having the light source device are disclosed. Alight source device includes a plurality of light-emitting diode (“LED”) strings and an LED driving circuit. The LED strings include LEDs emitting lights connected in serial. The LED driving circuit supplies a driving voltage to the LED strings. The LED driving circuit maximizes the driving voltage supplied to the LED strings by using the minimum string current of string currents supplied to each LED string in an initial driving period. The LED driving circuit supplies the maximum driving voltage to the LED strings by blocking a current flowing through a sensing resistor disposed to sense the minimum string current in a normal driving period.

Abstract: A power stage for light emitting diode (LED)-based light bulbs may include a bipolar junction transistor (BJT). The base of BJT switch may be biased externally and the operation of the BJT may be through a single pin to the emitter of the BJT. A controller integrated circuit (IC) may control the power stage through the main BJT's emitter pin in an emitter-controlled BJT-based power stage. The emitter-controlled BJT-based power stage may replace the conventional buck-boost power stage topology. For example, the controller may activate and deactivate a switch coupling the BJT's emitter to ground. A power supply for the controller IC may be charged from a reverse recovery of charge from the BJT, and the reverse recovery controlled by the controller IC.

Abstract: The invention proposes a method for operating an actively clocked PFC circuit (2) having a directly or indirectly connected load circuit (5) at the output of the PFC circuit (2), wherein the load circuit (5) has at least one luminous means, in particular one or more LEDs (4), wherein the PFC circuit (2) is controlled by a PFC controller (30) in such a manner that the PFC controller (30) determines a control parameter, in particular a switched-on time period (ton), for the clocking of the PFC circuit (2) on the basis of at least one first controller setting (RE_fast) and one second controller setting (RE_slow), wherein the time of a change from the first controller setting (RE_fast) to the second controller setting (RE_slow) is dependent on the directly or indirectly determined average value of the control parameter, in particular the switched-on time period (ton).

Abstract: Provided is a circuit for adjusting light-emitting diode (LED) current; the circuit comprises: a single-output constant current source (21), a multi-path LED output circuit (22) and a control bus (20) connected to the multi-path LED output circuit (22); any given LED output circuit comprises: a load circuit (23), an adjustment circuit (24), a current regulation circuit (25) and an adjustment control circuit (26). The circuit for adjusting LED current provided in the technical solution of the present invention adjusts the current of each LED output circuit via the load circuit, the adjustment circuit, the current regulation circuit and the adjustment control circuit, thus adjusting characteristic parameters such as color, color temperature, color rendering index, brightness and the like of the LED light source, thereby avoiding the problem of high cost caused by using multi-path constant current DC/DC circuit to adjust the current of each path.

Abstract: Apparatuses, methods, apparatuses and systems for commissioning a light fixture are disclosed. One method includes receiving, by the light fixture, a message from a central controller, wherein reception of the message puts the light fixture into a known condition, establishing communication between the light fixture and a user, and communicating, by either the light fixture or the user, a location of the user at a time of the established communication, to the central controller, thereby allowing the central controller to record a location of the light fixture.

Abstract: According to one embodiment, a power supply for lighting includes an output element. The output element is connected between a power supply and a lighting load, and configured to be capable of being switched to a switching operation repeating an ON state and an OFF state and an ON continuation operation continuing the ON state.

Abstract: In one embodiment, a driver circuit for light-emitting diodes has a first DC/DC converter (DCDC1) with an input (IN) for feeding a supply voltage (VBAT) and with a first output (OUT), a second DC/DC converter (DCDC2), which is coupled on the output side to the first output (OUT) and is designed for operation with energy supplied in advance, a current source (IFlash) that is connected to the first output (OUT), and a main output (LED OUT), which is coupled to the current source (IFlash) and is designed to be connected to the light-emitting diodes. The first DC/DC converter (DCDC1) is designed for operation in a current-limiting mode. The second DC/DC converter (DCDC2) is designed for regulation to a nominal voltage (Vds) of the current source (IFlash).

Abstract: A supplemental dimming circuit for an electronic led driver comprising a universal control section has a VCC3 startup and low conduction period circuit for providing a current during start-up and during low conduction periods; a CC hold current circuit for providing a hold current for the dimmer at low conduction periods; a latch circuit for providing a current draw latch on; and a PWM synchronized dimming circuit for providing a PWM signal dependent on the conduction period of the dimmer in real time. The supplemental dimming circuit also has a socket and a plug. The universal control section is on a daughter board that is pluggable to the socket. The VCC3 startup and low conduction period circuit creates a low AC voltage dummy load, which is a resistive load. The CC hold current circuit creates a low AC current dummy load that is a constant current load.

Abstract: A lighting system includes methods and systems to mix colors of light emitted from at least two LED emitters. In at least one embodiment, the lighting system includes a controller that responds to phase-cut angles of the dimming signal and correlates the phase-cut angles with a predetermined black body radiation function to dynamically adjust a color spectra of the mixed light in response to changes in phase cut angles of the phase-cut dimming level signal. In at least one embodiment, the controller utilizes the predetermined black body radiation function to dynamically adjust the color spectra of the mixed, emitted light in response to changes in phase cut angles of a phase-cut dimming level signal. In at least one embodiment, the predetermined black body radiation function specifies correlated color temperatures (CCTs) that model the CCTs of an actual non-LED based lamp, such as an incandescent lamp.

Abstract: A method for controlling an intelligent lamp to work automatically according to people's habit includes generating a table in the memory, the table records values of a group of operational parameters of the intelligent lamp each time a user operates the intelligent lamp. Determining a frequent event and an accidental event in the predetermined time period in one day in last one week/month/year. Then obtaining all values of the operational parameters of the frequent events, and respectively calculating an accuracy value for each operational parameter according to an algorithm. In addition, controlling the lighting unit to work according to the accuracy values of the operational parameters, thus, an intelligent lamp for automatically working according to people's habit is also provided.

Abstract: A cascoded current regulator, including: a first load circuit, having a first load and a current source unit; and a second load circuit, being cascaded with the first load circuit and having a second load and a current mirror unit, wherein a first current flowing through the first load and a second current flowing through the current source unit are controlled by a control voltage, and a third current flowing through the second load and a fourth current flowing through the current mirror unit are generated according to the second current.

Abstract: A control circuit adapted to control a power converting circuit for stabilizing an output of the power converting circuit is provided. The control circuit includes a capacitor, a charging unit, a discharging unit, a feedback control unit, and a duty-cycle adjusting unit. The charging unit has a first current source coupled to the capacitor for charging the capacitor. The discharging unit is coupled to the capacitor for discharging the capacitor. The feedback control unit controls the charging unit to charge the capacitor according to a feedback signal which represents the output of the power converting circuit. The duty-cycle adjusting unit generates a control signal and adjusts a duty cycle of the control signal according to a voltage of the capacitor.

Abstract: The light emitting device control circuit device 100 in accordance with the disclosure includes a power source V1, a transistor TR1, a light emitting unit EU1, switches S1 to S17, constant current sources CC1 to CC17, and a controller 110. A switching voltage Vs1 is supplied from the controller 110 to turn ON or turn OFF the transistor TR intermittently, a pulse voltage is supplied to a pulse voltage supplying line Y1 connected to a drain terminal D of the transistor TR1. The driving signals SP1 to SP17 are sequentially supplied to the switches S1 to S17 to turn ON or turn OFF them (i.e., time division drive). The light emitting devices A1 to A17 are driven sequentially by a pulse current (i.e., time division drive) when a high voltage is supplied to the pulse voltage supplying line Y1 and when the driving signals SP1 to SP17 are turned ON.

Abstract: A lighting device is provided, having at least one light emitting diode module, a power factor correction circuit, a non-regulated isolation DC to DC converter and at least one regulated non-isolation DC to DC converter. The power factor correction circuit performs a power factor correction on an AC power source and outputs a corrected DC voltage. The non-regulated isolation DC to DC converter generates an output voltage in a predetermined voltage range according to the corrected DC voltage, wherein the non-regulated isolation DC to DC converter is an open-loop controlled buck DC to DC converter. The regulated non-isolation DC to DC converter generates a fixed current or a fixed voltage according to the output voltage output from the non-regulated isolation DC to DC converter, thereby driving the light emitting diode module.

Abstract: A planar light-emitting module lighting circuit uses a lamp comprising an organic electroluminescence layer and electrodes sandwiching the organic electroluminescence layer as a load, and applies a current to the load so as to cause the organic electroluminescence layer to emit light. In the planer light-emitting module lighting circuit, a current at a lighting start time of the lamp is made small as compared with a current at a stationary lighting time at which a predetermined time period has passed since a lighting start.

Abstract: A driving power control circuit and method for light emitting diodes (LEDs) are provided. The driving power control circuit includes a plurality of switch units and a control unit. Each switch unit is electrically coupled to one LED string whose end generates node voltage. The control unit includes a voltage selecting module, a subtractor, and an adjusting module. The voltage selecting module is electrically coupled to the node voltages and outputs one of the node voltages as a reference node voltage. The subtractor is electrically coupled to an output terminal of the voltage selecting module and generates a corresponding feedback voltage according to the reference node voltage and the node voltage. The adjusting module is electrically coupled to an output terminal of the subtractor and outputs a corresponding adjusting signal according to the feedback voltage to determine whether the corresponding switch unit is turned on.

Abstract: An adaptive switch mode LED driver provides an intelligent approach to driving multiple strings of LEDs. The LED driver determines an optimal current level for each LED channel from a limited set of allowed currents. The LDO driver then determines a PWM duty cycle for driving the LEDs in each LED channel to provide precise brightness control over the LED channels. Beneficially, the LED driver minimizes the power dissipation in the LDO circuits driving each LED string, while also ensuring that the currents in each LED string are maintained within a limited range. A sample and hold LDO allows PWM control over extreme duty cycles with very fast dynamic response. Furthermore, fault protection circuitry ensures fault-free startup and operation of the LED driver.

Abstract: A dimmable ballast and methods are presented in which the operating frequency of a self-oscillating inverter is controlled according to a sensed lamp current for dimming control or cathode heating, and an AC bus voltage of the inverter is controlled to be at or below a voltage threshold value to prevent over driving operating lamps when one or more lamps are being replaced.

Abstract: A method of driving a light source includes adjusting a number of duty adjustments of driving signals driving light sources based on a dimming control signal and adjusting each duty ratio of each of the driving signals provided to each of the light sources in accordance with the adjusted number of the duty adjustments.

Abstract: A driver circuit, operating method, and use of a current mirror of a driver circuit is provided that includes at least one output transistor, a reference network with at least one reference transistor, a switching device, which is connected to the control input of the output transistor and to the control input of the reference transistor to form a switchable current mirror, a current source for providing a reference current for a reference current path, whereby the current source and the reference transistor are arranged in the reference current path, a load terminal, whereby the load terminal and the output transistor are arranged in a load current path, and at least one damping network, which is connected to or connectable to the reference current path. Wherein a connection of components of the at least one damping network and a connection of components of the reference network are substantially the same.

Abstract: A lighting device is provided, having at least one light emitting diode module, a power factor correction circuit, a non-regulated isolation DC to DC converter and at least one regulated non-isolation DC to DC converter. The power factor correction circuit performs a power factor correction on an AC power source and outputs a corrected DC voltage. The non-regulated isolation DC to DC converter generates an output voltage in a predetermined voltage range according to the corrected DC voltage, wherein the non-regulated isolation DC to DC converter is an open-loop controlled buck DC to DC converter. The regulated non-isolation DC to DC converter generates a fixed current or a fixed voltage according to the output voltage output from the non-regulated isolation DC to DC converter, thereby driving the light emitting diode module.

Abstract: A light source driving circuit for powering multiple light sources in a vehicle includes multiple current limiters and a balance controller. The current limiters are coupled to the light sources for adjusting currents of the light sources respectively. The balance controller coupled to the current limiters can control the current limiters such that a current flowing through each of the light sources is substantially the same as a first target current. Moreover, the balance controller can control the current limiters in response to a brake of the vehicle such that a current flowing through each of the light sources is substantially the same as a second target current.

Abstract: An LED driver circuit that includes a buck-mode boost converter that provides a regulated output current and that requires only a single connection to each channel of LEDs. The buck-mode boost controller may include a current regulator that includes an integrator. The current regulator may be configured to integrate a difference between a reference signal that is representative of the desired level of the average current through the electronic power switch and a detected signal that is representative of the actual current that is being delivered to the buck-mode boost circuit through the electronic power switch. The reference signal to the integrator may not change during operation of the buck-mode converter. The current regulator may be configured to deactivate the integrator and/or to disconnect the detected signal from the integrator while the electronic power switch is off.

Abstract: The invention relates to a method for operation of an actively clocked PFC circuit with a directly or indirectly connected load circuit at the output of the PFC circuit, wherein the load circuit has a lighting means, in particular one or more LEDs, wherein the PFC circuit is supplied at least with a measurement signal which reflects the power consumption of the load circuit or with an external control signal which indicates the power consumption, and a control circuit adjusts the mode of operation of the PFC circuit continuously or preferably in two or more steps, depending on the control signal or measurement signal.

Abstract: A circuit device for an LED's driving and stabilizing system includes an AC/DC controllable driving voltage source, a feedback driving controller, an LED demodulation driving controller controllable driving voltage source, an external regulator, and an LED modular device. While various internal conditions or factors of the circuit device may be obtained through integrally or partially setting and computing, the circuit device may also be externally connected to an input signal source according to the characteristics of different attributive conditions to thereby achieve the function of automatic regulation, enabling the LED modular device connected thereto and having been used over a long period of time to have lowered brightness attenuation rate, reduced power loss, reduced heat generation, and accordingly, extended the LED's lifespan.

Abstract: The present invention is related to the apparatus for driving the light emitting devices with different colors. The input powers of the light emitting devices are measured and controlled by a feedback control system to maintain constant, and by setting different power inputs to the different light emitting devices different stable colors are produced.

Abstract: A lamp detection driving system is disclosed for performing adaptive lamp driving and related detection operations based on a recipe. The system includes a micro-controller, a driver, a defect detection module and a feedback circuit. The micro-controller provides a modulation signal and a plurality of reference signals based on the recipe. The driver generates at least one driving signal for driving at least one lamp based on the modulation signal. The feedback circuit generates a plurality of feedback signals based on lamp currents or lamp voltages. The defect detection module generates a plurality of detection signals based on the reference signals and the feedback signals. Furthermore, disclosed is a lamp detection driving method including downloading the recipe, generating at least one driving signal for driving at least one lamp based on the recipe, and providing at least one reference signal for performing defect detection processes based on the recipe.

Abstract: A light-emitting device includes a plurality of light-emitting units, a plurality of non-address-embedded brightness control integrated circuits (ICs) and at least one system control unit. Each of the brightness control ICs is electrically connected to each of the light-emitting units. The system control unit addresses each of the brightness control ICs by outputting at least one addressing signal through an external circuit, and writes a brightness control signal to each of the brightness control ICs. Each brightness control IC controls each of the light-emitting units according to the received brightness control signal.

Abstract: Provided is an apparatus for driving a light emitting element. The apparatus includes a power unit, a light emitting element array, a constant-current circuit unit, and a voltage limiting circuit unit. The power unit supplies driving power. The light emitting element array includes a plurality of light emitting elements connected in series between an anode terminal connected to the power unit and a cathode terminal. The constant-current circuit unit maintains a constant current flowing through the light emitting element array according to a first tuning voltage. The voltage limiting circuit unit is connected between the cathode terminal of the light emitting element array and the constant-current circuit unit, and divides a total voltage applied between the cathode terminal of the light emitting element array and a ground according to a second tuning voltage to limit a voltage applied to the constant-current circuit unit below a predetermined voltage.

Abstract: A controller for controlling a voltage applied to a load from a power source includes a square wave producing circuit for connection in the circuit with the battery and the lamp. The square wave producing circuit produces a variable duty cycle square wave for controlling application of power to the load in accordance with the duty cycle of the square wave. The square wave producing circuit has a control input for varying the duty cycle of the square wave in response to a voltage at the control input. A voltage varying circuit is connected to the power source for producing a selectively variable voltage that is fed to the control input of the square wave producing circuit for selectively adjusting the duty cycle of the square wave.

Abstract: A computer system includes a voltage regulator that supplies power to a component. The component may provide a signal indicating an amount of current the component consumes under a high utilization operating condition. The voltage regulator may then determine the slope of a load line using this signal.

Abstract: An addressable lighting device and control system uses a DMX-512 protocol controller or other serial network protocol controller to selectively generate an electronic address for the addressable lighting device on which the device will respond to all future signals from the controller corresponding to that electronic address. The addressable device has a program mode for setting the address and a working mode for receiving control signals on the set address. The addressable device may have the address set and changed remotely using the DMX-512 protocol controller and a remote control to switch modes, thereby avoiding the problems associated with using DIP switches to set device electronic addresses.

Abstract: A series of arc lamps is ignited sequentially while maintaining a specified voltage on one side of each lamp with dielectric insulation on the high voltage side.

Abstract: A series of arc lamps each has an inductor connected in series with its anode which is field-coupled to a similar inductor connected to its cathode, the inductors being connected in series with each other through the inductors between an arc lamp power supply and a high current modulator for illuminating the arc lamps, once ignited. Ignition takes place serially from a single source of high voltage through respective charging networks, the charge time of each network being different from the others so as to successively create arcs in the arc lamps in sequence. The high voltage used for initial ignition of the arc lamps is differentially balanced to ground by means of the coils in series with the cathode and anode respectively of each arc lamp. The coils are poled so that the buildup of field in each coupled pair oppose each other, thereby rendering the coils invisible to the high current modulation during illumination of the arc lamps.

Abstract: In a lighting power controller having a controllable switch (such as a thyristor), in order to compensate for perturbations in the mains supply waveform, the waveform is analysed and a table is set up of thyristor firing angle against output RMS voltage. To obtain a desired output RMS voltage, the thyristor is fired at the angle indicated by the table.

Abstract: Ignition circuit for a gas discharge lamp. In the ignition circuit, the generating of uniform current pulses for ignition over the entire useful life of the gas discharge lamp is guaranteed. A control circuit is provided for holding constant the current-time integral of current pulses applied to the gas discharge lamp during ignition.

Abstract: During operation of ionized vapor discharge lamps and the partial load range, the lamp current is reduced from the rated value, the drop in voltage is measured during and after the reduction of the lamp current, and when the period of constant voltage that follows the drop in voltage is reached, the lamp current is increased accompanied by simultaneous determination of the increase in voltage. The lamp current is thereupon controlled in such a way that during the partial load range operation of the lamp, the voltage value is slightly greater than that of the voltage of the period of constant voltage.

Abstract: A circuit for operating a discharge lamp (1) by means of a direct voltage. The circuit comprises direct voltage terminals (A,B) for connection of a direct voltage source, alternating voltage output terminals (K,L) for connection to the discharge lamp, a direct voltage/alternating voltage sine converter (3), and a current limiter (5) for limiting the current through the lamp in its operating condition. A controllable direct voltage converter (2) is coupled between the sine converter and the direct voltage input terminals.