Abstract: A lighting device includes a light source that emits an illumination light. The light source includes a first group of light emitting diodes (LEDs) to emit a first light, a second group of LEDs to emit a second light, and a third group of LEDs to emit a third light. The second light is warmer light than the first light, and the third light is cooler light than the first light. The lighting device further includes a first difference amplifier that controls a first current flow through the second group of LEDs at least based on a magnitude of a current flowing through the light source. The lighting device also includes a second difference amplifier that controls a second current flow through the third group of LEDs at least based on the magnitude of the current flowing through the light source.

Abstract: A lighting fixture includes a light source that emits an illumination light and a receiver configured to receive a lighting control message from a photo sensor device. The lighting fixture further includes a lighting controller configured to adjust the illumination light based on the lighting control message. Adjusting the illumination light by the lighting controller includes changing a Correlated Color Temperature (CCT) of the illumination light.

Abstract: A luminaire can include a power supply that receives AC mains power from a power source and delivers intermediate power. The luminaire can also include a control module coupled to the power supply, wherein the control module receives the intermediate power from the power source, where the control module includes at least one first switch that has multiple positions, where each position of the at least one first switch corresponds to an output power level of a plurality of output power levels. The output power level can correspond to a discrete lumen output by a plurality of light sources of the luminaire.

Abstract: A lighting device includes a light source that emits an illumination light. The light source includes a first group of light emitting diodes (LEDs) to emit a first light, a second group of LEDs to emit a second light, and a third group of LEDs to emit a third light. The second light is warmer light than the first light, and the third light is cooler light than the first light. The lighting device further includes a first difference amplifier that controls a first current flow through the second group of LEDs at least based on a magnitude of a current flowing through the light source. The lighting device also includes a second difference amplifier that controls a second current flow through the third group of LEDs at least based on the magnitude of the current flowing through the light source.

Abstract: A luminaire can include a power supply that receives AC mains power from a power source and delivers intermediate power. The luminaire can also include a control module coupled to the power supply, wherein the control module receives the intermediate power from the power source, where the control module includes at least one first switch that has multiple positions, where each position of the at least one first switch corresponds to an output power level of a plurality of output power levels. The output power level can correspond to a discrete correlated color temperature (CCT) output by a plurality of light sources of the luminaire.

Abstract: A lighting device includes a ferroresonant transformer that receives an alternating current (AC) power signal and outputs an output power signal. The lighting device further includes a rectifier coupled to the ferroresonant transformer. The rectifier rectifies the output power signal from the ferroresonant transformer and generates a rectified power signal. The lighting device also includes a dc-to-dc converter coupled to the rectifier, wherein the dc-to-dc converter receives the rectified power signal and generates a regulated power signal.

Abstract: A lighting device includes a light source that emits an illumination light. The light source includes a first group of light emitting diodes (LEDs) to emit a first light, a second group of LEDs to emit a second light, and a third group of LEDs to emit a third light. The second light is warmer light than the first light, and the third light is cooler light than the first light. The lighting device further includes a first difference amplifier that controls a first current flow through the second group of LEDs at least based on a magnitude of a current flowing through the light source. The lighting device also includes a second difference amplifier that controls a second current flow through the third group of LEDs at least based on the magnitude of the current flowing through the light source.

Abstract: A lighting device include a first string of light emitting diodes (LEDs) to emit a white light having a warm white Correlated Color Temperature (CCT) and a second string of LEDs. The second string of LEDs includes blue light LEDs that emit a blue light and green light LEDs that emit a green light. The lighting device further includes a tuning circuit to adjust an amount of current flowing through the second string of LEDs. The warm white light, the blue light and the green light produce a combined light, and a CCT of the combined light is tuned by adjusting the amount of current flowing through the second string of LEDs.

Abstract: A lighting device includes a ferroresonant transformer that receives an alternating current (AC) power signal and outputs an output power signal. The lighting device further includes a rectifier coupled to the ferroresonant transformer. The rectifier rectifies the output power signal from the ferroresonant transformer and generates a rectified power signal. The lighting device also includes a dc-to-dc converter coupled to the rectifier, wherein the dc-to-dc converter receives the rectified power signal and generates a regulated power signal.

Abstract: A lighting device includes a light source that emits an illumination light. The light source includes a first group of light emitting diodes (LEDs) that emits a first light and a second group of LEDs that emits a second light. The first light has a first Correlated Color Temperature (CCT), and the second light causes the illumination light to have a warmer CCT. The lighting device further includes a differential amplifier to adjust a current flow through the second group of LEDs. The second light is switched on when a current provided to the light source is below a threshold corresponding to the adjustable reference voltage. The lighting device also includes a current sensor to provide a sensor output signal to a second input of the differential amplifier, the sensor output signal having a second voltage corresponding to the current provided to the light source.