A light emitting device includes a series connection unit constituted of N light emitting elements, a light emitting element driving circuit having an output terminal connected to an anode of the series connection unit, N short-circuit switches respectively connected in parallel to the light emitting elements, and a switch control unit arranged to control on and off of the short-circuit switches. A ground fault detection circuit, which detects a ground fault of the light emitting device, includes a reference voltage source arranged to generate a reference voltage, and a comparator arranged to compare the anode voltage of the series connection unit with the reference voltage. The reference voltage has a value smaller than the product of an on-resistance of one of the short-circuit switches and output current of the light emitting element driving circuit.

A lighting device circuit comprising: a reference LED string, a mirror LED string coupled in parallel to the reference LED string, an operational amplifier based current mirror circuit coupled to the reference LED string and to the mirror LED string, and a window comparator circuit that includes only a single input that is coupled to a fault sense node. The fault sense node directly connects to a drain node of a transistor within the operational amplifier based current mirror and a LED within the mirror LED string.

A lighting device circuit comprising: a reference LED string, a mirror LED string coupled in parallel to the reference LED string, an operational amplifier based current mirror circuit coupled to the reference LED string and to the mirror LED string, and a window comparator circuit that includes only a single input that is coupled to a fault sense node. The fault sense node directly connects to a drain node of a transistor within the operational amplifier based current mirror and a LED within the mirror LED string.

An airfield runway lamp controller is described herein. One airfield runway lamp controller includes a current sense transformer configured to detect a failure of a light source of an airfield runway lamp, and an alternating current (AC) switch configured to shunt the light source of the airfield runway lamp upon the current sense transformer detecting a failure of the light source.

Lighting fixtures are provided. In one example implementation, a lighting fixture can include a housing, one or more drivers, and means for securing the one or more drivers to the housing to decrease thermal resistance between one or more of the drivers and the housing. The lighting fixture can also include an LED system comprising a light engine having a plurality of LED devices. The plurality of LED devices can be arranged on an LED board of the light engine such that a first portion of the LED board has a first density of LED devices and a second portion of the LED board has a second density of LED devices. The first density can be different than the second density.

A lighting system (1) comprises a power unit (20) for producing data-modulated current, and a light unit (10) receiving this current at its input and output terminals (11, 12). The light unit comprises two or more light modules (100A; 100B; 100C) connected in series. Each light module comprises: a LED string (110) of one or more LEDs (111, 112, 113) connected between module input and output terminals (101, 102), each LED having an associated controllable shunt switch (121, 122, 123) connected in parallel thereto; a module controller (190) for controlling the shunt switches, the module controller (190) having a input terminals (191, 192) connected to said module input and output terminals, respectively. The module controller demodulates the data and controls the switches on the basis of an action command contained therein, if an address information contained therein matches the unique controller address.

A light emitting element driving semiconductor integrated circuit constitutes at least a part of a light emitting element driving device arranged to drive a series connection unit including a plurality of light emitting elements. The light emitting element driving semiconductor integrated circuit includes a single-element short-circuit detection unit arranged to detect that one of the plurality of light emitting elements is short-circuited, and a control unit arranged to control a power element of the light emitting element driving device so that current supplied from the light emitting element driving device to the series connection unit is increased, when the single-element short-circuit detection circuit detects that one of the plurality of light emitting elements is short-circuited.

Disclosed is a white and warm white LED synchronous intelligent flexible light assembly, which includes an intelligent power supply and flexible light strings, the intelligent power supply includes a plug, a controller, a female terminal of a power wire, and the flexible light strings, formed by white and warm white LED diodes, are connected in parallel to a main wire, an IP44 plug is connected to a power supply, a filter and a filter circuit which is connected to an input of a MOSFET, and direct current of a DC transformer is output to a driving module and an IRF, a signal output by the IRF passes through a heat dissipation component and the driving module, outputs of the driving module and the DC transformer are connected to the input of the MOSFET, and a signal of the MOSFET is output to the light strings.

Disclosed is a white and warm white LED synchronous intelligent flexible light assembly, which includes an intelligent power supply and flexible light strings, the intelligent power supply includes a plug, a controller, a female terminal of a power wire, and the flexible light strings, formed by white and warm white LED diodes, are connected in parallel to a main wire, an IP44 plug is connected to a power supply, a filter and a filter circuit which is connected to an input of a MOSFET, and direct current of a DC transformer is output to a driving module and an IRF, a signal output by the IRF passes through a heat dissipation component and the driving module, outputs of the driving module and the DC transformer are connected to the input of the MOSFET, and a signal of the MOSFET is output to the light strings.

In order to reduce energy loss of a tapped linear driver, it is proposed an LED lighting circuit, comprising an input (Vbus, GND) adapted to receive an input voltage, a plurality of LED segments (LED1, LED2, LED3, LED) connected in series and to the input, a buffer component (C9) connected to an anode and a cathode of a series string of at least two of the plurality of LED segments with respective switches, a current source circuit (B1) in series connection with a parallel connection of the buffer component and the at least two LED segments, across the input; further comprising a further buffer component (C5) across the current source circuit (B1), wherein said buffer component (C9) and the further buffer component (C5) is in series connection.