A driving device comprises a first transistor (B13), a second transistor (B14), and a resistance element. The first transistor (B13) has one terminal receiving a pulsed current and a control terminal connected to the one terminal. The second transistor (B14) has one terminal connected to at least one load, the other terminal connected to a reference potential together with the other terminal of the first transistor (B13), and a control terminal connected to the control terminal of the first transistor (B13). The resistance element is connected between the control terminal of the first transistor (B13) and the other terminal of the first transistor (B13).

A voltage-regulating drive circuit for an LED luminaire is disclosed. The drive circuit includes one or several series of LED light engines. A voltage source with a regulator is connected to the series of LED light engines to forward-bias the light engines. The circuit also includes a driver integrated circuit, which may drive the series of LED light engines using, e.g., pulse-width modulation (PWM). The circuit also includes a feedback circuit connected to the cathode end of the series of LED light engines. The feedback circuit receives a remainder voltage and creates a feedback output signal that upregulates or downregulates the regulator of the voltage source to keep a minimum operating voltage on the driver integrated circuit and to compensate for variations in forward voltages among LED light engines in the series.

A voltage-regulating drive circuit for an LED luminaire is disclosed. The drive circuit includes one or several series of LED light engines. A voltage source with a regulator is connected to the series of LED light engines to forward-bias the light engines. The circuit also includes a driver integrated circuit, which may drive the series of LED light engines using, e.g., pulse-width modulation (PWM). The circuit also includes a feedback circuit connected to the cathode end of the series of LED light engines. The feedback circuit receives a remainder voltage and creates a feedback output signal that upregulates or downregulates the regulator of the voltage source to keep a minimum operating voltage on the driver integrated circuit and to compensate for variations in forward voltages among LED light engines in the series.

A circuit board arrangement assembled by at least a first and a second circuit boards, each circuit board comprising: a portion of a circuit; and a first and a second electrical terminals to be electrically connected to a respective first and a second electrical terminals of the other circuit board of the first and the second circuit boards, so as to couple the portions of the circuit of the first and the second circuit boards, wherein the first and second electrical terminals on the circuit board are coupled with each other via the portion of the circuit on the other circuit board of the first and the second circuit boards, at least one board further comprising: a voltage suppression element (TSS1, TSS2) in the board connected across the first and second electrical terminals of the board, said voltage suppression element (TSS1, TSS2) is adapted to become conductive when a voltage thereacross reaches a threshold; characterized in that the portion of the circuit comprising at least one LED, and said LED (LED1) of the first circuit board (B1) and said LED (LED4) of the second circuit board (B2) are forwarded in the same direction and to be series connected between a first interconnection (LED+) of the first electrical terminals of the first and the second circuit boards and a second interconnection (LED−) of the second electrical terminal of the first and the second circuit boards. The voltage suppression element is able to prevent overvoltage/arcing due to a disconnection of the series connection of the LEDs of the first and second circuit boards, as well as a disconnection of a interconnection of first terminals, and a interconnection of the second terminals.

The disclosure provides a lighting device that provides light via one or more non- incandescent lamps that can be moved and arranged while operating. The lighting device includes a non-opaque shroud, or casing, that sits upon a base to create a volume within which the non-incandescent lamps rest and can be moved while still providing light. The non- incandescent lamp can use one or more light-emitting diodes (LEDs). The non-incandescent lamps can provide illumination with minimal heat and low power consumption that contributes to user interaction and can be battery powered. In addition to a non-incandescent lamp, a lighting device having at least one of the non-incandescent lamps is disclosed. Additionally, a lighting system having at least one of the lighting devices and a lighting control application is provided herein.

An illumination device and method are provided herein for calibrating individual LEDs in the illumination device to obtain a desired luminous flux and a desired chromaticity of the device over changes in drive current, temperature, and over time as the LEDs age. The calibration method may include subjecting the illumination device to a first ambient temperature, successively applying at least three different drive currents to a first LED to produce illumination at three or more different levels of brightness, obtaining a plurality of optical measurements from the illumination produced by the first LED at each of the at least three different drive currents, obtaining a plurality of electrical measurements from the photodetector and storing results of the obtaining steps within the illumination device to calibrate the first LED at the first ambient temperature. The plurality of optical measurements may generally include luminous flux and chromaticity, the plurality of electrical measurements may generally include induced photocurrents and forward voltages, and the calibration method steps may be repeated for each LED included within the illumination device and upon subjecting the illumination device to a second ambient temperature.

An illumination device and method are provided herein for calibrating individual LEDs in the illumination device to obtain a desired luminous flux and a desired chromaticity of the device over changes in drive current, temperature, and over time as the LEDs age. The calibration method may include subjecting the illumination device to a first ambient temperature, successively applying at least three different drive currents to a first LED to produce illumination at three or more different levels of brightness, obtaining a plurality of optical measurements from the illumination produced by the first LED at each of the at least three different drive currents, obtaining a plurality of electrical measurements from the photodetector and storing results of the obtaining steps within the illumination device to calibrate the first LED at the first ambient temperature. The plurality of optical measurements may generally include luminous flux and chromaticity, the plurality of electrical measurements may generally include induced photocurrents and forward voltages, and the calibration method steps may be repeated for each LED included within the illumination device and upon subjecting the illumination device to a second ambient temperature.

LED related lighting methods and apparatus are described. Various features relate to water tight light fixtures. Some of the fixtures are spotlights while other fixture are intended for in ground use. The light fixtures in at least some embodiments include power control features. In spotlight embodiments beam angle and power or light output can be controlled without opening the light assembly or compromising the water tight seals which also protect against dirt. In ground embodiments support tilt angle setting which allow a user to set the light fixture to one or more tilt angles. Beam angle can also be changed in some embodiments as well as power control. Beam angle, power control and tilt angle adjustments are supported in some embodiments but need not be supported in all embodiments with some embodiments using one or more of the described features but not all features.

A processor-based device includes a chassis having a chassis ground node that is arranged to electrically couple the chassis to an earth ground. The device also includes a connector accessible from an exterior of the chassis. The connector conforms to a standardized powerline interface having a hot power signal, a load power signal, and a neutral power signal. A processor-based apparatus housed at least in part within the chassis is arranged to operate using DC power derived from AC power present at the powerline interface. A stray voltage detector is arranged to detect a stray voltage potential existing between the neutral power signal of the standardized powerline interface and the chassis ground node, and the processor-based device is arranged to communicate at least one indication of the detected stray voltage potential.

A minimum voltage detector circuit is disclosed. The circuit includes a plurality of LED strings each having a plurality of series-coupled LEDs. The minimum voltage detector circuit is configured to detect a minimum voltage from among the plurality of LED strings, and also to perform open/short detection among the plurality of LED strings. The minimum voltage detector circuit includes a plurality of voltage comparators and correspondingly coupled replica circuits. Each of the voltage comparators includes an amplifier having a first input coupled to a cathode of a last LED of one of the plurality of LED strings, an output, and a second input coupled to the output. Each voltage comparator further includes a replica circuit coupled to the amplifier. The replica circuit is configured to maintain an output transistor of the amplifier in an active state when the amplifier is in an unbalanced state.