Abstract: Aspects of the present disclosure include a dimming device comprising a dimming signal interface module which includes an optical coupling module and an analog-digital converter module having its input terminal connected to the input terminal of the dimming signal interface module and its output terminal selectively connected to the optical coupling module. The dimming signal interface module may receive digital signals and analog signals. When the analog signals are received by the input terminal of the dimming signal interface module, the analog-digital converter module may convert the analog signals to square-wave signals and output the square-wave signals to the optical coupling module. When digital signals are received by the input terminal of the dimming signal interface module, the output terminal of the analog-digital converter module may be disconnected from the optical coupling module. The dimming device may be able to receive digital and analog control signals to be used for dimming.

Abstract: A control device may comprise a plurality of buttons, a plurality of light sources located behind the respective buttons and configured to illuminate the buttons, a light detector circuit configured to measure an ambient light level around the control device, and/or a control circuit configured to control the light sources to adjust surface illumination intensities of the respective buttons in response to the measured ambient light level. Each button may comprise indicia indicating a function of the button. The control circuit set the first button as active and the second button as inactive in response to an actuation of the first button. The control circuit may, based on the measured ambient light level, control the light sources to illuminate the first button to an active surface illumination intensity, and to illuminate the second button to an inactive surface illumination intensity that is less than the active surface illumination intensity.

Abstract: A gas discharge lamp includes at least two electrodes arranged in a manner spaced apart with a spacing in a discharge vessel filled with gas. A method of operating a ballast includes applying electrical energy to the electrodes. The ballast provides an electrical electrode current including a ripple current being dependent on an operating frequency of converter. Operating frequency is dependent on a charging time period and a discharging time period for an electrical energy store of the converter. The operating frequency is chosen such that the ripple current in the region of an arc discharge brings about a resonant excitation of the gas, and providing a pause time period between the discharging time periods and the respectively succeeding charging time period, the time duration of which pause time period is chosen such that a sum formed from the time periods attains the period duration corresponding to the operating frequency.

Abstract: Apparatuses and methods, the methods including installing a plurality of lighting fixtures, each of the lighting fixtures being installed at a location where they are to be operated and including at least one of a motion sensor and a global positioning system (GPS) device; receiving a signal from the plurality of lighting fixtures; storing a dataset including data representing the signals from the plurality of lighting fixtures; determining a correlation between the plurality of lighting fixtures and/or determining neighboring lighting fixtures for the plurality of lighting fixtures; and determining a topology of the installed lighting fixtures based on the determined correlation between the plurality of lighting fixtures.

Abstract: A device (1) for controlling the operation of a power load comprised in an apparatus (12) belonging to a terminal electrical installation (2) of an electrical network (16) on the basis of events that are related to the operation or management of the electrical distribution network. A method and the use of same for managing the power required in an electrical network via a plurality of devices, and a system including a plurality of devices for controlling the operation of a power load and an electrical distribution network are also described.

Abstract: An abnormality detection device includes a load connected to a load connection terminal; a first switching element, having one end connected to the load connection terminal, that switches between connection and disconnection of a power supply to the load; a control unit that switches between an on state and an off state of the first switching element; a detection unit that outputs a signal based on comparison between a voltage of the load connection terminal and a predetermined reference voltage; an acquisition unit that acquires the signal from the detection unit; a determination unit that determines that the load is in an abnormal state when the acquisition unit acquires an abnormality detection signal, which is a signal of a predetermined level, continuously for more than a predetermined first determination time period after the control unit switches the first switching element from the on state to the off state.

Abstract: Disclosed is a lighting apparatus using an LED as a light source. The lighting apparatus may connect first and second lighting units in series or parallel according to a rectified voltage, change one or more of first and second driving currents corresponding to light emissions of the first and second lighting units, and have the universality for rectified voltages.

Abstract: A switching power source device for controlling a current flowing through a coil by turning on/off a switching element by a PWM control to obtain a desired DC voltage, includes in a PWM ON period to turn on the switching element by the PWM control, a switching control of the switching element is enabled by a first pulse signal whose cycle is shorter than a PWM cycle based on the PWM control and whose pulse width is gradually increased, in a first period just after the PWM ON period is started, and the switching control of the switching element is enabled by the PWM signal based on the PWM control after the first period has elapsed.

Abstract: An image forming apparatus including a controller, which starts rotation of a rotary polygon mirror when a predetermined condition is satisfied, rotates the rotary polygon mirror at a predetermined rotation speed based on a first pulse in a first state in which light beams are not emitted from a light source, thereafter starts emission of the light beams, switches a rotation control based on the first pulse to a rotation control based on the second pulse, and rotates the rotary polygon mirror at the predetermined rotation speed based on the second pulse in a second state in which the light beams are emitted from the light source, and thereafter detects a temperature of a drive circuit board by a temperature detector, and corrects color misregistration using a detected temperature of the temperature detector and the detection result of a pattern detector.

Abstract: Embodiments of the present disclosure provide an array substrate and a display device, wherein the array substrate includes a plurality of scanning signal lines, a plurality of data lines, a plurality of pixel circuits disposed at intersections between the plurality of scanning signal lines and the plurality of data lines, a current source circuit connected to first ends of the plurality of data lines and configured to output a current to the pixel circuits through the plurality of data lines, and a constant current circuit connected to second ends of the plurality of data lines and configured to supply a current with a preset value flowing from the first ends to the second ends to the data lines. The display device includes the foregoing array substrate.

Abstract: A two-level LED security light within it has a light-emitting unit including an LED load which may be turned on or turned off by a loading and power control unit activated by a light sensing control unit and a motion sensing unit. When the motion sensing unit detects a motion signal, the light-emitting unit is switched to a high level illumination for a predetermined time length adjustable by a time setting unit, and then the loading and power control unit manages to turn off the light-emitting unit thru a soft off process. The LED load is configured with a plurality of LEDs accommodating to the power supply unit wherein a voltage V across each LED is confined in a range Vth<V<Vmax, with Vth being a minimum voltage to turn on the LED and Vmax a maximum voltage to avoid damaging the LED.

Abstract: A safety device comprises a light source, a power source coupled to the light source, a controller coupled to the light source and the power source to control operation of the lighting device, and a connection port that transmits and receives power up and control signals. In some embodiments, the connection port transmits and receives a wired signal. In further embodiments, the connection port transmits and receives a wireless signal. In some embodiments, the connection port receives a signal from an external source. In some of these embodiments, the external source is a remote control. In further embodiments, the external source is a program located on a computing device. In still further embodiments, the external source is one or more additional connection port of one or more additional safety devices. In some embodiments, the signal is a signal to power the light source.

Abstract: An illumination apparatus is described that includes a set of illumination components. The illumination apparatus also includes a housing structure having an overall width and an overall length. The housing structure includes a cavity to house the set of illumination components, which is defined by, at least, a first lateral wall of the housing structure and a second lateral wall of the housing structure that each extends along the overall length, and a base of the housing structure. The housing structure includes a set of openings on the base, where each opening extends from the first lateral wall to the second lateral wall.

Abstract: An energy supply device with connection portion for an energy source and an energy consumer. The energy supply device is arranged to feed energy from an energy source to an energy consumer, and also comprises energy storage for supplying a connected energy consumer with energy in the event of an interruption of energy supply. There is also a control unit and sensing portion for sensing an energy flow to and/or from the energy storage portion. The sensing portion is connected to the control unit which detects a power disturbance if there is an energy flow from the energy storage portion during a predefined length of time.

Abstract: An LED-based light includes one or more LEDs, a sensor arranged to detect a brightness level in an area resulting from the combination of light emitted by the LEDs with light from at least one ambient light source other than the LEDs, and operable to output a signal corresponding to the detected brightness level, a controller operable to regulate an amount of power provided to the LEDs in response to the signal, a light transmitting housing for the LEDs, the sensor and the controller and a connector shaped for connection with a light socket disposed at an end of the housing.

Abstract: A solid-state light source (SSLS) structure with integrated control. In one embodiment, a SSLS control circuit can be integrated with a SSLS structure formed from a multiple of SSLSs. The SSLS control circuit controls the total operating current of the SSLS structure to within a predetermined total operating current limit by selectively limiting the current in individual SSLSs or in groups of SSLSs as each are turned on according to a sequential order. The SSLS control circuit limits the current in each of the individual SSLSs or groups of SSLSs as function of the saturation current of the SSLSs. In one embodiment, the individual SSLSs or groups of SSLSs has a turn on voltage corresponding to a voltage causing a preceding SSLS or group of SSLSs in the sequential order to saturate current.

Abstract: Embodiments of the present disclosure disclose a method for adjusting color temperature and a device. The method comprises: acquiring a present light intensity parameter value of each of N primary colors of light emitted by a light source of a display device, determining a set light intensity parameter value of each of the N primary colors according to the present light intensity parameter value of each of the N primary colors and a pre-saved light intensity parameter value of each of the N primary colors, and respectively adjusting the light intensity of each of the N primary colors according to the set light intensity parameter value of the N primary colors.

Abstract: Provided is an ultra-high efficiency LED lamp driving device comprising: a plurality of shift switches connected to tabs between LED lamps; and an LED shift control unit for driving the shift switches so that lighting of the LED lamps is shifted to an end terminal when a total operation threshold voltage value of the LED lamp is equal to or greater than a maximum value of an input voltage, and thus, an unlighted LED lamp exists. The present invention can make the power loss be zero to thereby increase the efficiency.

Abstract: Systems and methods are provided for signal processing. An example error amplifier for processing a reference signal and an input signal associated with a current of a power conversion system includes a first operational amplifier, a second operational amplifier, a first transistor, a second transistor, a current mirror component, a switch, a first resistor and a second resistor. The first operational amplifier includes a first input terminal, a second input terminal and a first output terminal, the first input terminal being configured to receive a reference signal. The first transistor includes a first transistor terminal, a second transistor terminal and a third transistor terminal, the first transistor terminal being configured to receive a first amplified signal from the first output terminal, the third transistor terminal being coupled to the second input terminal.

Abstract: A lighting circuit includes a light emitting diode (LED), a transistor that controls a current through the LED, and a lighting controller integrated circuit (IC) that controls the transistor to vary a brightness of the LED. The controller IC has a dimming pin that receives a dimming signal. The controller IC generates a low reference threshold and a high reference threshold that follow the dimming signal. The lighting controller IC controls the transistor by hysteretic control by comparing a sense signal indicative of the current through the LED to the low reference threshold and the high reference threshold.

Abstract: A pixel driving circuit is disclosed, including: a driving switch, connected between a driving power source and an OLED; a first switch, connected between the drain of the driving switch and the driving power source for inputting a first control signal; a control circuit, connected between the drain and gate of the driving switch, for inputting a second control signal and outputting a compensation current to compensate threshold voltage drift of the driving switch; a storage unit, connected between the source of a second switch and gate of the first switch, for storing a compensation voltage of compensation current compensating the driving switch. A display panel and pixel driving method are also disclosed.

Abstract: A backlight unit of a display device includes a power converter to generate a light source voltage in response to a power control signal, a light emitting element connected between a first node and a second node, and a light source controller connected to the second node and to output the power control signal in response to a dimming signal. The light emitting element receives the light source power voltage through the first node. When a feedback voltage of the second node is lower than a first reference voltage, the light source controller outputs the power control signal having a first pulse width based on the feedback voltage and the dimming signal. When the feedback voltage is higher than the first reference voltage, the light source controller outputs the power control signal having a second pulse width based on a voltage lower than the feedback voltage and the dimming signal.

Abstract: A lighting system includes an electronic converter, a lighting module and a switching stage. The electronic converter includes a transformer, a rectifier circuit and an output filter circuit. A capacitance is connected between the primary winding and the secondary winding. The lighting module includes a chain of LEDs and a current regulator, wherein the chain of LEDs is mounted onto a substrate of a metallic material, so that a parasitic capacitance is present between the lighting module and the substrate of a metallic material. The switching stage includes a field-effect transistor interposed in the negative line which connects the lighting module to the electronic converter, and a control unit configured to drive the gate terminal of the transistor as a function of a dimming signal. The switching stage includes a diode connected to negative output terminal of the switching stage and to positive output terminal of the switching stage.

Abstract: An electronic system is disclosed. The electronic system is electrically connected to an alternative current (AC) power and includes a switch and a parallel power conversion device. The parallel power conversion device includes a first power conversion module, a second power conversion module, and a driver. The first power conversion module is electrically connected to the AC power source and the switch, the second power conversion module is electrically connected to the AC power source, and the driver is electrically connected to the second power conversion module. When a current outputted from the first power conversion module is smaller than a specific vale, the driver makes the second power conversion module operate in a sleep mode to stop outputting current and to reduce level of outputting voltage.

Abstract: The present disclosure provides a dimming device and a driving and dimming device, where the dimming device includes a communication unit, a microcontrol unit, a power supply unit and a connector, and the power supply unit is input with a mains voltage and outputs a voltage required by the communication unit, the communication unit receives a control signal obtained by wired or wireless transmission and outputs the control signal to the microcontrol unit, the microcontrol unit outputs a dimming signal for dimming, and the connector is detachably connected with a connector of another device.

Abstract: A programmable lighting control system integrates time-based, sensor-based, and manual control of lighting and other loads. The system includes one or more groups of controlled lighting areas, which may be, e.g., floors of a building. Each group may have one or more lighting zones, which may be, e.g., individual rooms or offices on a building floor. Each lighting zone includes occupancy and/or daylight sensors that may be wirelessly coupled to a gateway of the group. Each gateway is coupled to a network, such as, e.g., a local area network (LAN). Control software, residing on a computer (e.g., a personal computer or a server) coupled to the network and accessible via the network, remotely communicates with and controls the lighting zones either individually, groupwise, or globally. Each lighting zone can also be locally controlled at the gateway and can function independently of the control software and the gateway.

Abstract: A dimming module includes a triggering circuit, a control signal generating circuit, a voltage converting circuit, and a linear driving circuit. The triggering circuit is configured to control a trigger delay angle of an AC input voltage according to a dimming command, in order to output a first voltage signal correspondingly. The control signal generating circuit is configured to output a control voltage according to the first voltage signal. The voltage converting circuit is configured to output a DC operating voltage having an operating level according to the first voltage signal, and output the DC operating voltage to a lighting module, in which the lighting module includes a light-emitting diode. The linear driving circuit is configured to drive the lighting module according to the control voltage.

Abstract: A control device for controlling a plurality of lighting devices via a network is disclosed. The control device 100 comprises a receiver (102) for receiving a signal based on a user input related to adjusting a control parameter of the plurality of lighting devices (114, 116). The control device further comprises a processor (104) for generating, based on the received signal, on a predetermined network capacity and on the number of user input commands received within a predetermined time period, one of: a plurality of messages of a first type (108) and a single message of a second type (110). The control device further comprises a transmitter (106) for transmitting the generated plurality of messages of a first type (108) or the single message of a second type (110) via the network (112), thereby adjusting the control parameter of the plurality of lighting devices (114, 116). The control device is able to utilize the network optimally by generating messages based on their impact on the network.

Abstract: The supplemental circuit is for a power supply equipped with a power management integrated circuit (PMIC). The supplemental circuit includes a detection circuit producing input signals, a switch, a signal generation circuit producing a control signal controlling the switch's open and close according to the input signals, and a RC circuit. When the switch is closed, the PMIC and the RC circuit are series-connected to ground. The supplemental circuit resolves the reduced performance of the PMIC due to the field effect transistors (FETs) inside the PMIC suffering greater switching loss when the PMIC is constantly series-connected to ground through RC circuit.

Abstract: The invention describes an LED lighting system (1) comprising a wireless communication arrangement (11, 12) for wireless transfer of signals (D10_11, D11_12, D4_12, D5_12) between devices (10, 11, 12, 4, 5) of the LED lighting system (1); at least one LED lamp (10) connectable to a mains power supply (2), which LED lamp (10) comprises a driver arrangement (100) with a control unit (102) for controlling the LED lamp (10) according to a received signal (D10_11); a phase-cut detector (103A, 103B, 103C) realized to detect a phase-cut input (Vcut) to the LED lamp (10); and a protection circuit (106) realized to prevent operation of the LED lamp (10) with the phase-cut input (Vcut) if the phase-cut angle of the phase-cut input (Vcut) exceeds a critical threshold, wherein said protection circuit (106) is adapted to prevent an exposure of the LED lamp to the phase-cut input. The invention further describes an LED lamp (10) comprising a driver arrangement (100); and a method of controlling an LED lighting system (1).

Abstract: An illumination device comprises one or more emitter modules having improved thermal and electrical characteristics. According to one embodiment, each emitter module comprises a plurality of light emitting diodes (LEDs) configured for producing illumination for the illumination device, one or more photodetectors configured for detecting the illumination produced by the plurality of LEDs, a substrate upon which the plurality of LEDs and the one or more photodetectors are mounted, wherein the substrate is configured to provide a relatively high thermal impedance in the lateral direction, and a relatively low thermal impedance in the vertical direction, and a primary optics structure coupled to the substrate for encapsulating the plurality of LEDs and the one or more photodetectors within the primary optics structure.

Abstract: Embodiments of the present invention are directed to systems for powering and controlling lighting fixtures in office buildings, homes, industrial facilities, and similar structures using low-voltage direct-current (“DC”) electricity. Some embodiments of the present invention are directed to systems for distributing DC power from a lighting controller to various LED luminaires.

Abstract: Systems and methods are provided to control the color and brightness of LED lighting. A control signal generator generates a hybrid control signal using pulse width modulation and analog control to drive an LED driver with increased resolution to maintain color mixing while adjusting brightness of the LED lighting.

Abstract: A two-way load control system comprises a power device, such as a load control device for controlling an electrical load receiving power from an AC power source, and a controller adapted to be coupled in series between the source and the power device. The load control system may be installed without requiring any additional wires to be run, and is easily configured without the need for a computer or an advanced commissioning procedure. The power device receives both power and communication over two wires. The controller generates a phase-control voltage and transmits a forward digital message to the power device by encoding digital information in timing edges of the phase-control voltage. The power device transmits a reverse digital message to the controller via the power wiring.

Abstract: A light emitting device driving circuit according to the present disclosure includes a sawtooth waveform generating unit for generating a sawtooth waveform voltage having a sawtooth waveform voltage change based on at least two reference signals to be input and a comparison unit for comparing an analog signal voltage with the sawtooth waveform voltage. The light emitting device driving circuit drives a light emitting device based on the comparison result of the comparison unit. Accordingly, a comparison operation using a sawtooth waveform voltage having a waveform which is not disturbed is performed.

Abstract: A backlight unit includes: a power converter to generate a light-source power voltage according to a voltage control signal; an LED string connected to the light-source power voltage; a short-circuit detector to receive the light-source power voltage and to enable a short-circuit signal; and a light source controller to generate the voltage control signal to interrupt generation of the light-source power voltage when the short-circuit signal is enabled. The short-circuit detector includes: a voltage divider to divide the light-source power voltage to output a detection voltage; and a comparing circuit to generate a reference voltage corresponding to a voltage level of the detection voltage, to compare the reference voltage with the detection voltage, and to enable the short-circuit signal in accordance with a result of the comparison.

Abstract: The present invention involves use of at least two unidirectional elements to provide flow paths for the positive half cycle and the negative half cycle of the AC power input, respectively, and the at least two LED modules are integrated in the flow path of the positive half cycle and the negative half cycle, respectively, and a multi-stage driver module is integrated, so that when the positive half cycle or the negative half cycle is conducting, the at least two LED modules are lit up in different alternating orders, thereby rendering the light emission of the at least two LED modules substantially identical in an AC power cycle in terms of power and brightness. The invention overcomes the problem of uneven brightness of the LED lighting apparatus using a conventional multi-stage driver device.

Abstract: If there is an interruption of power to an electrical load while the electrical load is operating at low end, the electrical load may not turn back on when power is restored. This undesired operation may be avoided by detecting the application of power to the electrical load, and automatically increasing the magnitude of a control signal being applied to the electrical load by a sufficient amount for a short period of time after power has been applied. This way, the electrical load may be turned back on to low end, instead of erroneously operating in an electronic off condition.

Abstract: A lighting system and method for generating an output light beam representative of a target natural light are provided. The lighting system includes a plurality of solid-state light emitters each emitting a light sub-beam having an individual spectrum. The individual spectra of the solid-state light emitters collectively cover a visible portion of the natural light spectral profile and exclude infrared and ultraviolet components. The lighting system further includes a combining assembly combining the light sub-beams into the output light beam. A control module controls an intensity of the light sub-beam from each of the solid-state light emitters such that the resulting combined spectral profile of the output light beam is representative of a natural light spectral profile of the target natural light over its visible portion.

Abstract: Exemplary systems, methods, and apparatuses for distributed intelligence in facility lighting control are provided. A facility lighting system may be organized into multiple control areas, each of which may include one or more component devices. Each lighting control area may be associated with a control apparatus, which controls the operation of the lighting devices of the associated control area based on various types of signal information. Signal information may include information concerning local conditions or environments, as well as information from a centralized control server. Some embodiments further include monitoring the operation and predicting fault states of the lighting control area.

Abstract: A lighting controller and a control method make use of a fade time over which the light source is to be controlled when adjusting the light source output from a first dimming level to a second dimming level. The fade time is selected in dependence on both the difference between the first and second dimming values and the absolute values of the first and second dimming levels. This enables smooth fading over a long time when desired for a high quality fading with no flicker, or rapid fading between brightness levels when the speed of response is more important.

Abstract: According to an aspect, a display apparatus includes: a plurality of light sources; a display device irradiated with light from the light sources; and a controller. The display area includes a plurality of partial areas corresponding to the light sources on a one-to-one basis. Each of the partial areas includes a first area and a second area, the first area being irradiated with light from a first light source that corresponds thereto, and the second area being irradiated with light from the first light source and a second light source adjacent to the first light source. The controller controls an operation of the first light source based on whether the first area requires the light from the first light source and whether the second area obtains light required for display output by receiving the light from the second light source.

Abstract: A constant current power supply with a plurality of current outputs for LED lamps includes a DC/DC control module, an overvoltage detection circuit, a current sampling resistor, at least one output current conversion circuit and at least one overvoltage protection resistor. The output current conversion circuit includes a switch, a MOS transistor with a grid electrode electrically connected to the switch, and a current conversion sampling resistor. The overvoltage protection resistor is connected in series between the two voltage sampling resistors and the grid electrode of the MOS transistor. The constant current power supply of the present invention can output various current values through the output current conversion circuit so as to be able to adapt to different LED loads. One power supply can be applied in a variety of applications.

Abstract: A lighting device control system includes a lighting device that includes a communication interface, an optical radiation source, and a fixture controller. The system also may include a gateway controller that is in communication with the lighting device and one or more other lighting devices. The fixture controller or gateway controller identifies that a portable electronic device is in a proximate communication range. The fixture or gateway controller also receives a light operation request from the portable electronic device. The light operation request includes one or more settings for one or more optical characteristics of light that the optical radiation source may emit. The fixture controller determines whether the portable electronic device is authorized to implement the request. In response to determining that the device is authorized, the fixture controller will cause the optical radiation source to emit light that exhibits the optical characteristic(s).

Abstract: A microscope apparatus includes: a light source configured to emit illumination light to illuminate a specimen; a dimming input unit configured to set and input a light amount of the light source in a predetermined dimming range; a switching unit configured to switch a first instruction value instructing the light amount of the light source to a second instruction value larger than the first instruction value when a switching signal to switch the light amount of the light source is input; and a control unit configured to control a light amount of the illumination light emitted from the light source according to the first instruction value set and input by the dimming input unit or the second instruction value obtained by switching by the switching unit.

Abstract: A method for controlling an amount of power delivered to an electrical load may include controlling an average magnitude of a load current towards a target load current that ranges from a maximum rated current to a minimum rated current in a normal mode, and controlling the average magnitude of the load current below the minimum rated current in a burst mode. The burst mode may include at least one burst mode period that comprises a first time period associated with an active state and a second time period associated with an inactive state. During the burst mode, the method may include regulating a peak magnitude of the load current towards the minimum rated current during the active state, and stopping the generation of at least one drive signal during the inactive state to control the average magnitude of the load current to be less than the minimum rated current.

Abstract: A system controls lighting devices at one or more light-enabled facilities, each of which includes gateway controller at each facility. A facility's gateway controller pairs with a portable electronic device when the portable electronic device arrives at the facility. The gateway controller portable electronic device receives light operation requests from the portable electronic device upon arrival, or from the remote server before arrival. Each light operation request adjusts various hardware settings of the lighting devices to alter the optical characteristics of emitted light at various times. The system also may use geolocation data to identify and schedule lighting services at various light-enabled facilities in a geographic area.

Abstract: A method and circuit for driving an LED lighting device from an AC power source includes a rectifier and a plurality of strings of LEDs. Each string of LEDs includes a plurality of LEDs. A plurality of switches is controlled by a controller for opening and closing the switches. The controller is adapted to vary the number of strings conducting electricity by applying voltage from the rectifier to arrangements of the plurality of strings of LEDs selected based upon the present voltage of the output of the rectifier and the forward bias voltage of each of the strings of LEDs.

Abstract: A microcontroller receives a LINE SYNC signal and a dimmer control voltage input and controls output switch timing of an output FET switch to generate a reverse phase PWM dimming signal for supply to associated LED driver apparatus.

Abstract: A light emitting diode controller integrated circuit includes counter circuitry having inputs coupled to a clock signal input pin, a pulse width modulated signal input pin, and a sense input pin, and has a count output coupled to a gate drive signal output to an external power transistor. The power transistor is connected in series between a power lead, a sense resistor, and a light emitting diode. The sense input pin is coupled to the series connection between the resistor and the transistor. The counter circuitry provides a Ton_delay equal to a Toff_delay of the power transistor. By counting up during a Ton_delay and down during a Toff_delay, the controller can be used with power transistors of unknown characteristics.