Abstract: Representative embodiments of the invention provide a system, apparatus, and method of controlling an intensity and spectrum of light emitted from a solid state lighting system. The solid state lighting system has a first emitted spectrum at a full intensity level and at a selected temperature, with a first electrical biasing for the solid state lighting system producing a first wavelength shift, and a second electrical biasing for the solid state lighting system producing a second, opposing wavelength shift. Representative embodiments provide for receiving information designating a selected intensity level or a selected temperature; and providing a combined first electrical biasing and second electrical biasing to the solid state lighting system to generate emitted light having the selected intensity level and having a second emitted spectrum within a predetermined variance of the first emitted spectrum over a predetermined range of temperatures.

Abstract: Systems and methods for a digital-to-charge converter (“DQC”) are disclosed. A DQC may include a converting circuit configured to receive a first digital signal indicative of a voltage across a capacitor coupled to an output pin of the digital-to-charge converter and to determine a present charge of the capacitor based at least in part on the first digital signal. The DQC may also include an error determining circuit coupled to the converting circuit, wherein the error determining circuit is configured to receive a second digital signal indicative of a target charge via an input pin of the digital-to-charge converter and to determine a difference between the target charge and the present charge. The DQC may further include a correction circuit coupled to the error determining circuit and configured to control a programmable current source to produce an analog signal at the output pin in response to the determined difference.

Abstract: The invention provides a current balancing circuit, which includes a plurality of light-emitting diode assemblies; an AC power generator for providing currents required by the light-emitting diode assemblies; and a plurality of current-equaling elements connected to the AC power generator, each of which is connected to a common mode connecting two light-emitting diode assemblies for balancing currents of the light-emitting diode assemblies.

Abstract: A simple, cost-effective and efficient short circuit protection with simple routing of the ground on the PCB is achieved in an asynchronous DC-DC boost converter wherein a voltage sensing controller selectively isolates an input power supply to a load in the event of a short circuit. The controller alleviates need for additional components by utilizing the circuit for under voltage lockout protection and the circuit for overvoltage protection to generate signals for detecting short circuit. A predetermined offset voltage is added to a sensed output voltage to generate a reference voltage that is compared to a sensed input voltage and an output signal having a high state is generated in the event that the reference voltage is less than the sensed input voltage for selectively disabling the source of input power when the output signal is in the high state.

Abstract: The present application relates to a lighting applications. In particular, the present application describes examples of lighting fixtures and light bulbs containing a light transmissive optic. The orientation of the solid state emitters together with the contoured output surface of the light transmissive optic produce a tailored light output distribution over a designated planar surface. The light generated by the solid state light emitters is of a sufficient intensity to illuminate the designated planar surface.

Abstract: An apparatus includes first and fourth bypasses, a current detector, and a current controller. The first bypass is connected serially to a first LED, and controls the current amount in the first LED. The fourth bypass is connected serially to a second LED, and controls the current amount in the first and second LEDs. The detector detects current detection signal based on the current amount on an output line along which the first and second LEDs are connected serially to each other. The controller provides control signal for controlling the first and fourth bypasses based on the detection signal. The controller includes one output for providing the control signal. The first and fourth bypasses are connected in parallel to the one output.

Abstract: A lighting device such as an electronic ballast or LED driver includes a power factor correction (PFC) controller responsive to input power supply signals to generate control signals, a PFC boost converter responsive to said control signals to generate a boosted output voltage, and a fast start circuit with a power supply source and an energy storage device, a magnitude of the input power supply signal corresponding to energy stored in the energy storage device. During a first mode, the fast start circuit responds to a rectified mains input to enable the power supply source and charge the energy storage device. During a second mode, the fast start circuit responds to a magnitude of the power supply signal to disable the power supply source and discharge the energy storage device. The boost converter during the second operating mode maintains controller operation while the power supply source is disabled.

Abstract: An LED lighting device includes a first luminescent device for providing light according to a first current, a second luminescent device coupled in series to the first luminescent device for providing light according to a second current, an impedance device for limiting the second current within a predetermined range when a voltage established across the first luminescent device and the second luminescent device exceeds a first predetermined value, and a two-terminal current controller coupled in parallel with the first luminescent device and in series to the second luminescent device and configured to regulate the second current according to a voltage established across the two-terminal current controller.

Abstract: Various particle transport systems and components for use in such systems are described. The systems utilize one or more traveling wave grids to selectively transport, distribute, separate, or mix different populations of particles. Numerous systems configured for use in two dimensional and three dimensional particle transport are described.

Abstract: A driver circuit includes a buck converter associated with each LED chain for supplying a load current thereto. The buck converter receives an input voltage and is configured to provide a supply voltage to the associated LED chain such that the resulting load current of the LED chain matches at least approximately a predefined reference current value. The driver circuit further includes a switching converter that receives a driver supply voltage from a power supply and provides, as an output voltage, the input voltage for the buck converters. The switching converter is configured to provide an input voltage to the buck converters such that the maximum of the ratios between the input voltage and the supply voltages provided to the LED chains matches a predefined tolerance reference ratio.

Abstract: LEDs that provide street illumination are used to create emergency signals. This facilitates simple retrofitting of existing streetlighting infrastructure. In one embodiment, a streetlight comprises an LED set that itself comprises or consists of a plurality of LEDs collectively producing a white light output. The streetlight also includes a receiver for receiving a signal of an alarm condition, and a controller for (i) disabling the LED set during a daylight period, (ii) maintaining the normal operating mode during a lighting period distinct from the daylight period, and (iii) in response to the alarm condition detected by the receiver, de-activating at least one of the LEDs to produce a non-white (e.g., red or amber) output signaling the alarm condition.

Abstract: A pulse is input to first and second TFTs to turn ON the first and second TFTs so that the potential of a node a rises. When the potential of the node a reaches (VDD?VthN), the node ? enters a floating state. Accordingly, a third TFT then turns ON, and potential of an output node rises as a clock signal reaches the level H. On the other hand, potential of a gate electrode of the third TFT further rises due to an operation of capacitance as the potential of the output node rises, so that the potential of the output node would be higher than (VDD+VthN). Thus, the potential of the output node rises to VDD without voltage drop caused by a threshold of the third TFT.

Abstract: An LED (Light-Emitting Diode) driving circuit to drive an LED module is provided. The LED driving circuit includes a converting circuit and a feedback control circuit. The converting circuit is coupled to the LED module, and converts an input voltage into an output voltage according to at least one control signal. The feedback control circuit generates the control signal to control the converting circuit to perform voltage conversion according to a feedback signal. In addition, the feedback control circuit receives a dimming signal, and is operated in a first state or a second state in response to the dimming signal, wherein the feedback control circuit adjusts the duty cycle of the control signal to have the duty cycle larger than or equal to a predetermined duty cycle in a predetermined period right after the feedback control circuit is operated from the second state to the first state.

Abstract: A multi-modal load control system includes a sensor that operates as an occupancy sensor in a first mode of operation and operates as a vacancy sensor in a second mode of operation. The load control system comprises a load control circuit adapted to be coupled in series electrical connection between an AC power source and an electrical load for controlling the amount of power delivered to the load in response to sensor, which is operable to detect occupancy or vacancy conditions in a space in which the sensor is located. In the first mode of operation, the load control circuit turns the load on when the sensor detects the occupancy condition and turns the load off when the sensor detects the vacancy condition. In the second mode of operation, the load control circuit turns the load off when the sensor detects the vacancy condition and does not turn the load on when the sensor detects the occupancy condition.

Abstract: In various embodiments, a startup circuit for a low-voltage-lighting electronic transformer includes a low-impedance output circuit. At the beginning of an AC signal cycle, the low-impedance output circuit presents a low-impedance path to the output of the transformer, thereby causing a surge of current in the transformer and initiating oscillation therein.

Abstract: Systems, apparatuses, and methods are provided that include alterable characteristics and such alterable characteristics may be coordinated. Such systems, apparatuses, and methods may include wearable apparatuses and such alterable characteristics may relate to illumination conditions. In one example, a wearable apparatus includes an illumination device that may be manually manipulated between two different illumination conditions. In another example, two wearable apparatuses may each include an illumination device and operation of the two illumination devices may be coordinated. In a further example, operation of an apparatus may be controlled by a third party or venue. Still another exemplary system may include a capturing device for capturing a characteristic of an object and controlling an output device of an apparatus to operate with the same characteristic as the captured characteristic.

Abstract: Embodiments described herein provide a LED lighting system and method. A transformer has a primary winding and a secondary winding. A plurality of LED strings are coupled to the secondary winding of the transformer. At least one switch is coupled to at least one of the plurality of LED strings. A controller is coupled to the at least one switch and configured to control the operation of the at least one switch such that current flows through the plurality of LED strings in an alternating manner.

Abstract: A lamp ballast is provided for igniting and operating an HID lamp. A buck inverter circuit includes a pair of high-frequency and a pair of low-frequency switches. A capacitor and an inductor are series-connected between a first node between the low frequency switches and a second node between the high frequency switches. A lamp igniting circuit is coupled between the first node and a first lamp output terminal, and a second lamp output terminal is coupled to a third node between the capacitor and the inductor. A control circuit turns on and off the switches to regulate low frequency square wave voltage generated across the lamp output terminals to be less than an input DC voltage from the positive rail, wherein the buck inverter operates in either of a critical discontinuous mode or a discontinuous mode during an open circuit operation, and in a critical discontinuous mode during other operations.

Abstract: A representative apparatus embodiment provides for controlling current supplied to solid state lighting, such as light emitting diodes. A representative apparatus comprises a memory adapted to store a plurality of current parameters, and a control circuit adapted to modulate an energizing cycle time period for providing a substantially constant DC average current to the solid state lighting in response to a selected current parameter from the plurality of current parameters. In a representative embodiment, the control circuit modulates a current provided to the solid state lighting in response to a predetermined minimum current level (IMIN) parameter and a predetermined peak current level (IP) parameter, such that the DC average current level (IO) is substantially proportional to one-half of a sum of a predetermined peak current level (IP) and a predetermined minimum current level IMIN ( I O ? I P + I MI ? ? N 2 ) .

Abstract: An LED (Light-Emitting Diode) output power adjusting device includes an analog/digital conversion and detection circuit, a computation and control unit, a digital/analog conversion control circuit, and a power supply circuit. The analog/digital conversion and detection circuit is connected to an LED based load to detect a forward voltage thereof and converts the forward voltage into an output of digital signal. The computation and control unit perform evaluation and computation on the digital signal of the forward voltage to obtain a digital current control signal indicating a corresponding current. The digital/analog conversion control circuit converts the digital current control signal into an analog current control signal, which is then fed to a constant current drive circuit of the LED based load to adjust an output power of the LED based load to approximate a constant power condition.