A system includes two or more phosphor-containing white LEDs (or other color-shifting artificial light sources) selected so that their combined color shift over at least 8,000 hours (e.g., at least 10,000 hours, at least 20,000 hours, at least 30,000 hours, at least 40,000 hours, up to 200,000 hours, up to 100,000 hours, up to 80,000 hours) of operation is less than at least one of the LED's (or the other color-shifting artificial light source's) color shift over that time. Here, the combined color shift (Δu′v′) over the at least 8,000 hours (e.g., at least 10,000 hours, at least 20,000 hours, at least 30,000 hours, at least 40,000 hours, up to 200,000 hours, up to 100,000 hours, up to 80,000 hours) of operation can be less than 0.007 (e.g., 0.006 or less, 0.005 or less, 0.004 or less, 0.003 or less, 0.002 or less, 0.001 or less, 0.0005 or less).

A system includes two or more phosphor-containing white LEDs (or other color-shifting artificial light sources) selected so that their combined color shift over at least 8,000 hours (e.g., at least 10,000 hours, at least 20,000 hours, at least 30,000 hours, at least 40,000 hours, up to 200,000 hours, up to 100,000 hours, up to 80,000 hours) of operation is less than at least one of the LED's (or the other color-shifting artificial light source's) color shift over that time. Here, the combined color shift (Δu′v′) over the at least 8,000 hours (e.g., at least 10,000 hours, at least 20,000 hours, at least 30,000 hours, at least 40,000 hours, up to 200,000 hours, up to 100,000 hours, up to 80,000 hours) of operation can be less than 0.007 (e.g., 0.006 or less, 0.005 or less, 0.004 or less, 0.003 or less, 0.002 or less, 0.001 or less, 0.0005 or less).

An array-type light-emitting device includes multiple pixel circuits electrically coupled in parallel and spatially arranged in a matrix. A power supply circuit supplies electric power to the array-type light-emitting device. A DC/DC converter has an output coupled to a power supply terminal of the array-type light-emitting device via a power supply line. A power supply control circuit sets a target value that corresponds to a light distribution pattern, and controls the DC/DC converter such that the control target voltage approaches the target value.

Systems and methods for monitoring, detecting, measuring, altering, optimizing, and/or modifying electrical power delivered to a power consuming device. The power consuming device can be a light, speakers, fans, motors, any household electronic appliance, or other power consuming device. Also disclosed are light assemblies including a first plurality of strings of red LED lights, a second plurality of strings of green LED lights, and a third plurality of strings of blue LED lights (e.g., SMD LEDs). The light assembly also includes a driver configured to intermittently supply power from a power source to the red LED lights, green LED lights, and blue LED lights. The light assembly also includes a housing to house the light assembly, the driver, the power source, and a controller.

A load regulation device, such as an LED driver, may be configured to control the intensity of a light source based on an analog control signal and a preconfigured dimming curve. The LED driver may sense a magnitude of the analog control signal and determine a new low-end and/or high-end control signal magnitude that falls outside of the input signal range of the dimming curve. The LED driver may rescale the preconfigured dimming curve according to new low-end and/or high-end control signal magnitudes and dim the light source based on the rescaled dimming curve. Multiple LED drivers controlled by the same analog control signal may communicate with each other regarding the magnitude of the analog control signal sensed by each LED driver, and match their target intensity levels despite sensing different analog control signal. A controller may be provided to coordinate the operation of the multiple LED drivers.

A load regulation device, such as an LED driver, may be configured to control the intensity of a light source based on an analog control signal and a preconfigured dimming curve. The LED driver may sense a magnitude of the analog control signal and determine a new low-end and/or high-end control signal magnitude that falls outside of the input signal range of the dimming curve. The LED driver may rescale the preconfigured dimming curve according to new low-end and/or high-end control signal magnitudes and dim the light source based on the rescaled dimming curve. Multiple LED drivers controlled by the same analog control signal may communicate with each other regarding the magnitude of the analog control signal sensed by each LED driver, and match their target intensity levels despite sensing different analog control signal. A controller may be provided to coordinate the operation of the multiple LED drivers.

A lighting device may include a light source, a plurality of drive circuits, and a control circuit. The light source may include a plurality of emitter circuits that are configured to emit light. The light source may include a first emitter circuit that is configured to emit light at a first color (e.g., color temperature), a second emitter circuit is configured to emit light at a second color (e.g., color temperature), and a third emitter circuit is configured to emit light at a third color (e.g., color temperature). The first, second, and third colors (e.g., color temperatures) may be on a color curve, such as a color temperature curve like the black body locus. The control circuit may be configured to control the amount of power delivered to no more than two emitter circuits to emit light when controlling the light emitted by the light source to the target intensity.

A control method includes A) determining intrinsic activation times of individual semiconductor emitters of a display device. The display device includes a plurality of light-emitting semiconductor emitters with different intrinsic activation times. The method also includes B) determining and storing in each case an activation delay and/or a turn-on current change for each individual one of the semiconductor emitters. The method further includes C) energizing the individual semiconductor emitters according to the previously determined activation delay and/or turn-on current change, so that in a display mode of the display device the semiconductor emitters have equally long starting times for a light emission.

A load control device may be configured to control multiple characteristics of one or more electrical loads such as the intensity and color of a lighting load. The load control device may switch from controlling one characteristic of the electrical loads to controlling another characteristic of the electrical loads based on the position and/or orientation of one or more components of the load control device. Such a position and/or orientation may be manipulated by moving the one or more components relative to a base portion of the load control device. The load control device may be a wall-mounted device or a battery-powered remote control device.

A control device may be configured to control an amount of power delivered to one or more electrical loads and provide various feedback associated with the control device and/or the electrical loads. The control device may be a wall-mounted device or a battery-powered remote control device. The feedback may indicate the amount of power delivered to the one or more electrical loads. The feedback may also indicate a low battery condition. The control device may include a light bar and/or one or more indicator lights for providing the feedback.