An LED arrangement comprising at least one LED, which receives an LED illumination voltage in accordance with a square-wave signal, wherein the brightness of the LED is dependent on the ambient luminosity, which is measured by means of the LED, which is switched in a non-illuminated state as a light sensor. The at least one LED is arranged together with a first and a second transistor in a bridge circuit such that the first transistor applies the LED illumination voltage to the LED in accordance with the square-wave signal, and the second transistor applies a voltage having inverted polarity as the LED illumination voltage to the LED in intervals of the turned-off times of the LED, wherein the duty cycle of the square-wave signal is dependent on the strength of a photocurrent, which flows through the LED when the voltage having inverted polarity is applied thereto.

An LED arrangement comprising at least one LED, which receives an LED illumination voltage in accordance with a square-wave signal, wherein the brightness of the LED is dependent on the ambient luminosity, which is measured by means of the LED, which is switched in a non-illuminated state as a light sensor. The at least one LED is arranged together with a first and a second transistor in a bridge circuit such that the first transistor applies the LED illumination voltage to the LED in accordance with the square-wave signal, and the second transistor applies a voltage having inverted polarity as the LED illumination voltage to the LED in intervals of the turned-off times of the LED, wherein the duty cycle of the square-wave signal is dependent on the strength of a photocurrent, which flows through the LED when the voltage having inverted polarity is applied thereto.

An LED tube lamp comprises a plurality of LED light sources, an end cap, a power supply disposed in the end cap, a lamp tube, and an LED light strip. The lamp tube extends in a first direction along a length of the lamp tube, and has an end attached to the end cap. LED light strip is electrically connected the LED light sources with the power supply. The LED light strip has in sequence a first wiring layer, a dielectric layer and a second wiring layer. A thickness of the second wiring layer is greater than a thickness of the first wiring layer.

Disclosed herein is a lighting apparatus capable of uniformly maintaining power consumed by light emitting units even in the case in which various voltages are applied, and increasing power efficiency while minimizing a heating problem by adjusting a reference voltage applied to a connection structure of the light emitting units and a distribution switch according to magnitude of the applied voltage.

An interior light, in particular for shelf or display case illumination, includes an adjustment unit, which has a lens; a main body, which has a cylindrical recess inside which a lighting means is arranged; at least one guide which is provided on the recess and extends parallel to a cylinder axis of the recess; and latch means which are arranged in the region of the recess and have a plurality of latching stages, the adjustment unit having mating latch means which can latch to the latch means and guide means for guiding the adjustment unit in the guide; the guide means being arranged in each case at different positions within the guide when the mating latch means latch to the different latching stages, and a different distance being set between the lighting means and the lens in each case.

A lighting system is disclosed that includes lighting zones. Each of the lighting zones include LED light fixtures with different sets of LED arrays mounted to modular light boards that emit different output spectra. Each of the zones also includes a layer pack control unit coupled to the LED light fixture to control power to the LED light fixtures and to execute or run lighting protocols. The lighting system preferably includes a user interface device coupled to LED light fixtures in each of the light zones through a system bus and is capable independently control light output from the LED light fixtures in each of the zones.

A load control device for controlling the amount of power delivered to an electrical load may include a rectifier circuit configured to receive a phase-control voltage and produce a rectified voltage. A power converter may be configured to receive the rectified voltage at an input and generate a bus voltage. An input capacitor may be coupled across the input of the power converter. The input capacitor may be adapted to charge when the magnitude of the phase control voltage is approximately zero volts. The power converter may be configured to operate in a boost mode, such that the magnitude of the bus voltage is greater than a peak magnitude of the input voltage. The power converter may be configured to operate in a buck mode to charge the input capacitor from the bus voltage when the magnitude of the phase-control voltage is approximately zero volts.

A ballast circuit for a lighting system using an induction fluorescent lamp utilizes an AC-DC rectification circuit, a DC-DC boost power conversion circuit, a DC-AC half bridge inverter circuit, and a resonating circuit to ignite the lamp and maintain substantially constant power output of the lamp, while the DC-AC half bridge inverter circuit is further comprised of a gate isolation transformer connected in a half bridge inverter schematic which uses a ballast integrated circuit (IC) to drive a high side MOSFET and a low side MOSFET and the gate isolation transformer electrically isolates a gate signal to the high side MOSFET.

An LED tube lamp includes a glass tube, a plurality of LED light sources, two end caps respectively sleeving two end portions of the glass tube, a power supply in one of the end caps or separately in both of the end caps, and an LED light strip in the glass tube. The plurality of LED light sources is on the LED light strip. Each of the end caps comprises a plurality of openings formed thereon. The plurality of openings dissipating heat resulted from the power supply are divided into two sets. The two sets of the plurality of openings are symmetric to each other with respect to a virtual central axis of the end cap.

The disclosure is directed to an obstruction lighting and power line control system. The system includes at least one light source, at least one controller coupled to and configured to control the at least one light source, a power line cable providing power to the at least one light source, and a power supply coupled to the power line cable and configured to provide power to the at least one light source over the power line cable. The disclosure further includes a system controller configured to control the power supply to provide power over the power line cable to the at least one light source and the at least one controller that indicates at least one of the following: operating parameters and operating modes.