A power supply including: an AC input power connector; an AC-DC converter circuit coupled to the AC input power connector; a constant-current constant-voltage control unit configured to receive DC power from the AC-DC converter circuit; a light emitting diode (LED) lamp unit configured to receive power from the constant-current constant-voltage control unit; and a capacitor coupled in parallel with the LED lamp unit.

In order to make flexible, reliable lighting possible for industrial image processing, it is provided that a lighting unit (2), having a lighting device (5) comprising a number of light sources (6), receives a set value of the lighting via a data bus from a lighting control unit (10), that the lighting unit (2) captures a state variable (Z) of the lighting unit (2) and/or the surroundings of the lighting unit (2), and that the lighting unit (2) adjusts the set value in a closed control loop separately and independently from the lighting control unit (10) in that a control variable for at least one light source (6) is calculated in the lighting unit (2) and adjusted at the at least one light source (6).

A primary-side controlled high power factor, low total harmonic distortion, quasi resonant converter converts an AC mains power line input to a DC output for powering a load, such as a string of LEDs. The AC mains power line input is supplied to a transformer that is controlled by a power switch. A device for controlling a power transistor of a power stage includes a shaper circuit including a first current generator configured to output a first current responsive to a bias voltage signal and to generate a reference voltage signal based on the first current. A bias circuit includes a second current generator configured to output a second current responsive to a compensation voltage signal and to generate the bias voltage based on the second current. An error detection circuit includes a third current generator configured to output a third current responsive to the reference voltage signal and to generate the compensation voltage signal based on the third current. A driver circuit has a first input configured to receive the reference voltage signal and having an output configured to drive the power transistor.

UV hard-surface disinfection system that is able to disinfect the hard surfaces in a room, while minimizing missed areas due to shadows by providing multiple UV light towers that can be placed in several areas of a room such that shadowed areas are eliminated and that can be transported by a cart that is low to the ground such that the towers may be loaded and unloaded easily by a single operator. The system is able to be controlled remotely, such that during activation of the system, no operator is present, and to automatically cut power to all towers in the event that a person enters the room.

A solid state light source driver circuit that operates in either a buck convertor or a boost convertor configuration is provided. The driver circuit includes a controller, a boost switch circuit and a buck switch circuit, each coupled to the controller, and a feedback circuit, coupled to the light source. The feedback circuit provides feedback to the controller, representing a DC output of the driver circuit. The controller controls the boost switch circuit and the buck switch circuit in response to the feedback signal, to regulate current to the light source. The controller places the driver circuit in its boost converter configuration when the DC output is less than a rectified AC voltage coupled to the driver circuit at an input node. The controller places the driver circuit in its buck converter configuration when the DC output is greater than the rectified AC voltage at the input node.

The present disclosure relates to a lighting fixture that includes a driver module and at least one other module that provides a lighting fixture function, such as a sensor function, lighting network communication function, gateway function, and the like. The driver module communicates with the other modules in a master/slave scheme over a communication bus. The driver module is configured as a slave communication device, and the other modules are configured as master communication devices. As such, the other modules may initiate communications with the driver to send information to or retrieve information from the driver module.

A light emitting diode device has a bulk gallium and nitrogen containing substrate with an active region. The device has a lateral dimension and a thick vertical dimension such that the geometric aspect ratio forms a volumetric diode that delivers a nearly uniform current density across the range of the lateral dimension.

A circuit and a method of operating LED lighting elements are described. The circuit comprises a first and a second LED lighting element (20, 30). In order to provide a circuit and operating method with reduced complexity, a control circuit (50) controls operation of the first LED lighting element in dependence on a light feedback signal L from a light sensitive element (52). The signal L is dependent on light emitted from the second LED lighting element (30). Said first and said second LED lighting element (20, 30) are in series connection and said control circuit (50) is in parallel connection with said first LED lighting element (20); or said first and said second LED lighting element (20, 30) are in parallel connection and said control circuit (50) is in series connection with said first LED lighting element (20).

Flexible light engines capable of being cut, and methods thereof, are provided. A cuttable flexible light engine includes a flexible strip and strings of solid state light sources coupled in parallel. A voltage balancer establishes a desired current flow through the strings of solid state light sources when the flexible strip is cut to a desired length, and may be part of a connector placed where the strip is cut. The strings may be provided in a first set of strings coupled in parallel between a first conductive path and an intermediate conductive path and a second set of strings coupled in parallel between the intermediated conductive path and a second conductive path. A cuttable flexible light engine may also include test points positioned within the strings.

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.