Abstract: Methods and apparatus for changing a DC supply voltage applied to a lighting circuit are disclosed. In specific cases, a constant voltage power supply is used to power an LED lighting circuit in which there are uncertainties within the forward voltages of the LEDs, which in turn creates uncertainty with respect to the current level flowing through the LEDs. To manage these uncertainties, the current flowing through the LEDs is measured and an indication of the current level is communicated to a person who can manually adjust the DC voltage supply applied to the LED lighting apparatus by the constant voltage power supply. Alternatively, an automatic adjustment of the DC voltage supply applied to the LED lighting apparatus by the constant voltage power supply can be performed based upon the measured current level.

Abstract: Circuits for sensing current levels within an apparatus are disclosed. In specific cases, a constant voltage power supply is used to power an LED lighting apparatus in which there are uncertainties within the forward voltages of the LEDs, which in turn creates uncertainty with respect to the current level flowing through the LEDs. To manage these uncertainties, the current flowing through the LEDs is measured by determining a voltage level across a known resistor and calculating the current level. To prevent the known resistor from causing a significant reduction in the efficiency of the overall light engine, the circuit includes one or more transistors in parallel with the known resistor to reduce the effective resistance in the LED circuit during times that the current is not being sensed.

Abstract: A lighting apparatus may comprise a voltage converter operable to supply a current to at least two LED channels coupled between a high voltage rail and a low voltage rail coupled to the voltage converter output. The LED channels may be operated to selectively allow a current to flow through them. The lighting apparatus may have a control module operable to control the total current from the voltage converter and the current through each of the LED channels. The control module may also be operable to set the respective control signals to maintain a constant total current from the voltage converter while permitting aspects of the light output including, the intensity, color, and color temperature to be set and varied. Additionally, the control module may be operable to synchronize the various control signals, obtain a representative sample of the current through the voltage converter, and operate in different modes.

Abstract: Lighting apparatus and methods for controlling lighting apparatus using ambient light levels are disclosed. A controller is used to activate and deactivate one or more light radiating devices within a duty cycle. The controller uses a light detection apparatus to sample ambient light levels at a plurality of sampling times during which the light radiating devices are deactivated. The controller determines an average for the light levels sampled over a survey time period, thus generating an averaged ambient light level over the survey time period. The controller adjusts an intensity of the light radiating devices based at least partially upon the averaged ambient light level. The controller may generate a target light level using the averaged ambient light level over the survey time period and a desired light level and, over an adjustment time period, incrementally adjust the intensity of the light radiating devices towards the target light level.

Abstract: A LED based lighting apparatus is disclosed. The light engine used in the lighting apparatus may use a multi-layer metal core printed circuit board and have a plurality of LED groups that are independently controllable by a control unit. The power supply input and return paths connected to each LED group may be implemented on different layers to allow a compact footprint that may be used with traditional fluorescent encasements with relatively little modification.

Abstract: The present invention discloses a lighting apparatus that includes a plurality of parallel circuits and a common circuit. The parallel circuits each comprise a switching transistor and a set of LEDs, the sets of LEDs having different characteristics such as different light output wavelengths. In operation, one of the parallel circuits is selected by activating the corresponding switching transistor, thus selecting the respective LEDs to be activated. The common circuit also comprises a set of LEDs, these LEDs being activated no matter which parallel circuit is selected. In various implementations, the lighting apparatus can generate a wide spectrum of light outputs by selectively activating the plurality of parallel circuits within time slots of a duty cycle. In some cases, balancing of loads across the parallel circuits is desired to maintain the appropriate current flowing through the LEDs.

Abstract: Control apparatus for controlling an aspect of an apparatus are disclosed. In certain embodiments, the control apparatus comprises a dimmer that includes a variable impedance. In certain embodiments of the invention, the dimmer may be a TRIAC dimmer having a voltage at a gate electrode of the TRIAC that is always below a trigger voltage for the TRIAC such that the TRIAC never turns on and the remaining components within the TRIAC dimmer can be used as discreet components in a larger circuit. In the control apparatus, the dimmer may be coupled to a signal generation circuit that may generate an output signal whose frequency (period) is dictated at least in part by an impedance of the variable impedance. The output signal may be used to control an aspect of an apparatus such as the intensity, color or color temperature for a lighting apparatus.

Abstract: Control apparatus for controlling an aspect of an apparatus are disclosed. In certain embodiments, the control apparatus comprises a dimmer that includes a variable impedance. In certain embodiments of the invention, the dimmer may be a TRIAC dimmer having a voltage at a gate electrode of the TRIAC that is always below a trigger voltage for the TRIAC such that the TRIAC never turns on and the remaining components within the TRIAC dimmer can be used as discreet components in a larger circuit. In the control apparatus, the dimmer may be coupled to a signal generation circuit that may generate an output signal whose frequency (period) is dictated at least in part by an impedance of the variable impedance. The output signal may be used to control an aspect of an apparatus such as the intensity, color or color temperature for a lighting apparatus.

Abstract: Control apparatus for controlling an aspect of an apparatus are disclosed. In certain embodiments, the control apparatus comprises a dimmer that includes a variable impedance. In certain embodiments of the invention, the dimmer may be a TRIAC dimmer having a voltage at a gate electrode of the TRIAC that is always below a trigger voltage for the TRIAC such that the TRIAC never turns on and the remaining components within the TRIAC dimmer can be used as discreet components in a larger circuit. In the control apparatus, the dimmer may be coupled to a signal generation circuit that may generate an output signal whose frequency (period) is dictated at least in part by an impedance of the variable impedance. The output signal may be used to control an aspect of an apparatus such as the intensity, color or color temperature for a lighting apparatus.

Abstract: A method for controlling pulse width modulated lighting devices within a lighting apparatus comprising a plurality of sets of lighting devices is disclosed. The method includes setting a counter for a first set of the plurality of sets of lighting devices using a master counter and an activation duration for one or more other sets of the plurality of sets of lighting devices. The method further includes determining an activation time period within a duty cycle for the first set of lighting devices using the counter for the first set of lighting devices and an activation duration for the first set of lighting devices. In some embodiments of the present invention, the lighting devices are light emitting diodes grouped into sets (or banks) and controlled to limit the magnitude and/or quantity of instantaneous current fluctuations in a power supply within the lighting apparatus.

Abstract: Circuits for sensing current levels within an apparatus are disclosed. In specific cases, a constant voltage power supply is used to power an LED lighting apparatus in which there are uncertainties within the forward voltages of the LEDs, which in turn creates uncertainty with respect to the current level flowing through the LEDs. To manage these uncertainties, the current flowing through the LEDs is measured by determining a voltage level across a known resistor and calculating the current level. To prevent the known resistor from causing a significant reduction in the efficiency of the overall light engine, the circuit includes one or more transistors in parallel with the known resistor to reduce the effective resistance in the LED circuit during times that the current is not being sensed.

Abstract: Lighting apparatus may comprise elongated segments interconnected perpendicularly to form a grid light engine, each segment comprising groups of LEDs on both sides such that, when interconnected together, the grid light engine is operable to emit light inwardly to a plurality of grid squares formed by the segments. The apparatus may further comprise a back panel light engine comprising LEDs, the back panel light engine being coupled adjacent to the grid and operable to emit light from its LEDs through the grid. This architecture can allow for light from different sets of LEDs to be projected in different directions. When the different sets of LEDs emit different spectrum outputs, the light fixture can appear visually different depending upon the viewers' perspective. When the different sets of LEDs are controlled separately, visual effects such as the appearance of depth, sunrises and sunsets can be generated.

Abstract: A method for controlling pulse width modulated lighting devices within a lighting apparatus comprising a plurality of sets of lighting devices is disclosed. The method includes setting a counter for a first set of the plurality of sets of lighting devices using a master counter and an activation duration for one or more other sets of the plurality of sets of lighting devices. The method further includes determining an activation time period within a duty cycle for the first set of lighting devices using the counter for the first set of lighting devices and an activation duration for the first set of lighting devices. In some embodiments of the present invention, the lighting devices are light emitting diodes grouped into sets (or banks) and controlled to limit the magnitude and/or quantity of instantaneous current fluctuations in a power supply within the lighting apparatus.

Abstract: A lighting apparatus may comprise a voltage converter operable to supply a current to at least two LED channels coupled between a high voltage rail and a low voltage rail coupled to the voltage converter output. The LED channels may be operated to selectively allow a current to flow through them. The lighting apparatus may have a control module operable to control the total current from the voltage converter and the current through each of the LED channels. The control module may also be operable to set the respective control signals to maintain a constant total current from the voltage converter while permitting aspects of the light output including, the intensity, color, and color temperature to be set and varied. Additionally, the control module may be operable to synchronize the various control signals, obtain a representative sample of the current through the voltage converter, and operate in different modes.

Abstract: Circuits for sensing current levels within an apparatus are disclosed. In specific cases, a constant voltage power supply is used to power an LED lighting apparatus in which there are uncertainties within the forward voltages of the LEDs, which in turn creates uncertainty with respect to the current level flowing through the LEDs. To manage these uncertainties, the current flowing through the LEDs is measured by determining a voltage level across a known resistor and calculating the current level. To prevent the known resistor from causing a significant reduction in the efficiency of the overall light engine, the circuit includes one or more transistors in parallel with the known resistor to reduce the effective resistance in the LED circuit during times that the current is not being sensed.

Abstract: Lighting apparatus and methods for controlling lighting apparatus using ambient light levels are disclosed. A controller is used to activate and deactivate one or more light radiating devices within a duty cycle. The controller uses a light detection apparatus to sample ambient light levels at a plurality of sampling times during which the light radiating devices are deactivated. The controller determines an average for the light levels sampled over a survey time period, thus generating an averaged ambient light level over the survey time period. The controller adjusts an intensity of the light radiating devices based at least partially upon the averaged ambient light level. The controller may generate a target light level using the averaged ambient light level over the survey time period and a desired light level and, over an adjustment time period, incrementally adjust the intensity of the light radiating devices towards the target light level.

Abstract: A LED based lighting apparatus is disclosed. The light engine used in the lighting apparatus may use a multi-layer metal core printed circuit board and have a plurality of LED groups that are independently controllable by a control unit. The power supply input and return paths connected to each LED group may be implemented on different layers to allow a compact footprint that may be used with traditional fluorescent encasements with relatively little modification.

Abstract: Lighting apparatus and method for detecting reflected light from local objects are disclosed. A controller within a lighting apparatus is used to activate and deactivate one or more LEDs within a duty cycle. The controller uses a light detection apparatus that is optically isolated from the LEDs to sample light levels during a time in which the LEDs are deactivated and during a time in which the LEDs are activated. The light level when the LEDs are deactivated is an indication of the ambient light levels within the surrounding area of the lighting apparatus. The light level when the LEDs are activated is an indication of the ambient light levels combined with any light generated by the LEDs that is reflected onto the light detection apparatus. By comparing these light levels, the controller can determine the level of light attributable to reflected light from the LEDs.

Abstract: The present invention is directed to method, system and computer-readable media for controlling lighting devices. In some embodiments, a method for controlling pulse width modulated lighting devices within a lighting apparatus comprising a plurality of sets of lighting devices is disclosed. The method includes setting a counter for a first set of the plurality of sets of lighting devices using a master counter and an activation duration for one or more other sets of the plurality of sets of lighting devices. The method further includes determining an activation time period within a duty cycle for the first set of lighting devices using the counter for the first set of lighting devices and an activation duration for the first set of lighting devices. In some embodiments of the present invention, the lighting devices are light emitting diodes grouped into sets (or banks) and controlled to limit the magnitude and/or quantity of instantaneous current fluctuations in a power supply within the lighting apparatus.

Abstract: The present invention discloses a lighting apparatus that includes a plurality of parallel circuits and a common circuit. The parallel circuits each comprise a switching transistor and a set of LEDs, the sets of LEDs having different characteristics such as different light output wavelengths. In operation, one of the parallel circuits is selected by activating the corresponding switching transistor, thus selecting the respective LEDs to be activated. The common circuit also comprises a set of LEDs, these LEDs being activated no matter which parallel circuit is selected. In various implementations, the lighting apparatus can generate a wide spectrum of light outputs by selectively activating the plurality of parallel circuits within time slots of a duty cycle. In some cases, balancing of loads across the parallel circuits is desired to maintain the appropriate current flowing through the LEDs.