Abstract: Lighting systems and methods implementing toggle control are provided. In one example implementation, a lighting system can include a first LED array having one or more LED devices and a second LED array having one or more LED devices. The system can further include a single throw circuit interrupter configured to receive power from a power source. The system can further include a power conversion circuit configured to convert an input power received via the toggle switch to a power output for the first LED array and the second LED array. The power conversion circuit can be configured to control a power distribution ratio between the first LED array and the second LED array based at least in part on a detected toggle input (e.g., a toggle pattern) implemented using the single throw circuit interrupter.

Abstract: Systems and methods for controlling a light emitting diode (LED) system associated with an area and having a plurality of LED arrays are provided. In some implementations, the lighting system can include a first LED array associated with visible light and a second LED array associated with UV light. The lighting system can include one or more first sensors configured to detect occupancy within the area and send signals indicating whether the area is occupied. The lighting system can include one or more second sensors configured to detect microbes within an area and send signals indicating whether microbes are present in the area. The lighting system can include a control circuit configured to receive the signals sent by the one or more first and second sensors and to control the first LED array and the second LED array based on the signals.

Abstract: Lighting systems and methods implementing toggle control are provided. In one example implementation, a lighting system can include a first LED array having one or more LED devices and a second LED array having one or more LED devices. The system can further include a single throw circuit interrupter configured to receive power from a power source. The system can further include a power conversion circuit configured to convert an input power received via the toggle switch to a power output for the first LED array and the second LED array. The power conversion circuit can be configured to control a power distribution ratio between the first LED array and the second LED array based at least in part on a detected toggle input (e.g., a toggle pattern) implemented using the single throw circuit interrupter.

Abstract: Lighting systems and methods implementing toggle control are provided. In one example implementation, a lighting system includes a first LED array having one or more LED devices and a second LED array having one or more LED devices. The system further includes a single throw circuit interrupter configured to receive power from a power source. The system further includes a power conversion circuit configured to convert an input power received via the toggle switch to a power output for the first LED array and the second LED array. The power conversion circuit is configured to control a power distribution ratio between the first LED array and the second LED array based at least in part on a detected toggle input (e.g., a toggle pattern) implemented using the single throw circuit interrupter.

Abstract: Systems and methods for controlling a light emitting diode (LED) system associated with an area and having a plurality of LED arrays are provided. In some implementations, the lighting system can include a first LED array associated with visible light and a second LED array associated with UV light. The lighting system can include one or more first sensors configured to detect occupancy within the area and send signals indicating whether the area is occupied. The lighting system can include one or more second sensors configured to detect microbes within an area and send signals indicating whether microbes are present in the area. The lighting system can include a control circuit configured to receive the signals sent by the one or more first and second sensors and to control the first LED array and the second LED array based on the signals.

Abstract: Systems and methods for controlling a light emitting diode (LED) system associated with an area and having a plurality of LED arrays are provided. In some implementations, the lighting system can include a first LED array associated with visible light and a second LED array associated with UV light. The lighting system can include one or more first sensors configured to detect occupancy within the area and send signals indicating whether the area is occupied. The lighting system can include one or more second sensors configured to detect microbes within an area and send signals indicating whether microbes are present in the area. The lighting system can include a control circuit configured to receive the signals sent by the one or more first and second sensors and to control the first LED array and the second LED array based on the signals.

Abstract: The invention provides semiconductor materials including a gallium nitride material layer formed on a silicon substrate and methods to form the semiconductor materials. The semiconductor materials include a transition layer formed between the silicon substrate and the gallium nitride material layer. The transition layer is compositionally-graded to lower stresses in the gallium nitride material layer which can result from differences in thermal expansion rates between the gallium nitride material and the substrate. The lowering of stresses in the gallium nitride material layer reduces the tendency of cracks to form. Thus, the invention enables the production of semiconductor materials including gallium nitride material layers having few or no cracks. The semiconductor materials may be used in a number of microelectronic and optical applications.

Abstract: Lighting systems and methods implementing toggle control are provided. In one example implementation, a lighting system includes a first LED array having one or more LED devices and a second LED array having one or more LED devices. The system further includes a single throw circuit interrupter configured to receive power from a power source. The system further includes a power conversion circuit configured to convert an input power received via the toggle switch to a power output for the first LED array and the second LED array. The power conversion circuit is configured to control a power distribution ratio between the first LED array and the second LED array based at least in part on a detected toggle input (e.g., a toggle pattern) implemented using the single throw circuit interrupter.

Abstract: Lighting fixtures and methods for controlling operation of lighting fixtures are provided. In one example implementation, a lighting fixture includes a first LED array associated with a first color temperature, and a second LED array associated with a second color temperature. The lighting fixture further includes a circuit configured to adjust a power distribution amongst the first LED array and the second LED array based at least in part on a detected toggle input to adjust a color temperature of light output by the lighting fixture.

Abstract: The invention provides semiconductor materials including a gallium nitride material layer formed on a silicon substrate and methods to form the semiconductor materials. The semiconductor materials include a transition layer formed between the silicon substrate and the gallium nitride material layer. The transition layer is compositionally-graded to lower stresses in the gallium nitride material layer which can result from differences in thermal expansion rates between the gallium nitride material and the substrate. The lowering of stresses in the gallium nitride material layer reduces the tendency of cracks to form. Thus, the invention enables the production of semiconductor materials including gallium nitride material layers having few or no cracks. The semiconductor materials may be used in a number of microelectronic and optical applications.

Abstract: The invention provides semiconductor materials including a gallium nitride material layer formed on a silicon substrate and methods to form the semiconductor materials. The semiconductor materials include a transition layer formed between the silicon substrate and the gallium nitride material layer. The transition layer is compositionally-graded to lower stresses in the gallium nitride material layer which can result from differences in thermal expansion rates between the gallium nitride material and the substrate. The lowering of stresses in the gallium nitride material layer reduces the tendency of cracks to form. Thus, the invention enables the production of semiconductor materials including gallium nitride material layers having few or no cracks. The semiconductor materials may be used in a number of microelectronic and optical applications.

Abstract: Systems and methods for characterizing solid state lighting devices are provided. In certain examples, systems and methods for measuring various parameters of light emitting diodes (LEDs), characterizing each LED based on the measured parameters and selecting one or more of the characterized LEDs such that the emitted light from each of the selected LEDs is mixed with the light from the other selected LEDs to create a desired overall light output are described.

Abstract: Lighting systems and methods implementing toggle control are provided. In one example implementation, a lighting system includes a first LED array having one or more LED devices and a second LED array having one or more LED devices. The system further includes a single throw circuit interrupter configured to receive power from a power source. The system further includes a power conversion circuit configured to convert an input power received via the toggle switch to a power output for the first LED array and the second LED array. The power conversion circuit is configured to control a power distribution ratio between the first LED array and the second LED array based at least in part on a detected toggle input (e.g., a toggle pattern) implemented using the single throw circuit interrupter.

Abstract: A light fixture having master circuit boards and one or more LED circuit boards connectable in various alternative combinations for light fixtures having alternative lengths, the master board including a switch and AC-DC rectifier and the LED boards including linear AC drivers and one or more LED arrays, the switch on the master board controlling the linear AC drivers on the LED board or boards.

Abstract: Lighting systems and methods implementing toggle control are provided. In one example implementation, a lighting system includes a first LED array having one or more LED devices and a second LED array having one or more LED devices. The system further includes a single throw circuit interrupter configured to receive power from a power source. The system further includes a power conversion circuit configured to convert an input power received via the toggle switch to a power output for the first LED array and the second LED array. The power conversion circuit is configured to control a power distribution ratio between the first LED array and the second LED array based at least in part on a detected toggle input (e.g., a toggle pattern) implemented using the single throw circuit interrupter.

Abstract: A semiconductor material includes a compositionally-graded transition layer, an intermediate later and a gallium nitride material layer. The compositionally-graded transition layer has a back surface and a top surface, and includes a gallium nitride alloy. The gallium concentration in the compositionally-graded transition layer increases from the back surface to the front surface. The intermediate layer is formed under the compositionally-graded transition layer. The gallium nitride material layer is formed over the compositionally-graded transition layer, and has a crack level of less than 0.005 ?m/?m2.

Abstract: Systems and methods for controlling a light emitting diode (LED) system associated with an area and having a plurality of LED arrays are provided. In some implementations, the lighting system can include a first LED array associated with visible light and a second LED array associated with UV light. The lighting system can include one or more first sensors configured to detect occupancy within the area and send signals indicating whether the area is occupied. The lighting system can include one or more second sensors configured to detect microbes within an area and send signals indicating whether microbes are present in the area. The lighting system can include a control circuit configured to receive the signals sent by the one or more first and second sensors and to control the first LED array and the second LED array based on the signals.

Abstract: Systems and methods for controlling a light emitting diode (LED) system having a plurality of LED arrays are provided. The lighting system can include a dimmable LED driver circuit configured to provide a driver output suitable for providing a driver current to the LED arrays. A current splitter circuit can be provided between the LED driver circuit and the plurality of LED arrays to control the ratio of current from the driver output provided to each of the plurality of LED arrays. The current splitter circuit can be configured to control the current ratio provided to the plurality of LED arrays independently of the driver output according to a current ratio control curve based at least in part on a variable reference signal provided at the current splitter circuit.

Abstract: A light fixture having master circuit boards and one or more LED circuit boards connectable in various alternative combinations for light fixtures having alternative lengths, the master board including a switch and AC-DC rectifier and the LED boards including linear AC drivers and one or more LED arrays, the switch on the master board controlling the linear AC drivers on the LED board or boards.

Abstract: Multiphase lighting fixtures having one or more light emitting diode (LED) light sources are provided. In one example implementation, a light fixture includes one or more light sources, such as LED light sources and a power conversion circuit. The power conversion circuit includes a phase shifting transformer for implementing a phase shift between output phases of secondary windings thereof, a multi-phase rectifier having a first rectifier and a second rectifier connected in parallel for converting a multiphase input power to a rectified output or a six-pulse configuration, a zero sequence blocking transformer for reducing harmonic distortion, an interphase transformer for further reducing harmonic distortion, and a current regulator for providing a constant DC current output to the one or more light sources. In some example implementations, the DC rectified output has a voltage ripple of less than about 7%, or less than about 3%.