Abstract: Controlling the color temperature of a composite light source including at least one discrete-spectrum light source is disclosed. For example, the color temperature of a composite light source including at least one discrete-spectrum light source may be determined and/or adjusted based on one or more of the ambient color temperature of a space, the actual temperature of the space, the relative brightness of the space, the occupancy of the space, a time clock, a demand response command (e.g., from an electrical utility), the absolute location of the composite light source, the location of the composite light source relative to other light sources, inputs from a camera or other external devices, the operation of appliances or other machines in the vicinity of the composite light source, media content being utilized in the vicinity of the composite light source, and/or other sensor inputs.

Abstract: A multi-stage power supply for a load control device is able to operate in a low-power mode in which the power supply has a decreased power consumption when an electrical load controlled by the load control device is off. The load control device comprises a load control circuit and a controller, which operate to control the amount of power delivered to the load. The power supply comprises a first efficient power supply (e.g., a switching power supply) operable to generate a first DC supply voltage. The power supply further comprises a second inefficient power supply (e.g., a linear power supply) operable to receive the first DC supply voltage and to generate a second DC supply voltage for powering the controller. The controller controls the multi-stage power supply to the low-power mode when the electrical load is off, such that the magnitude of the first DC supply voltage decreases to a decreased magnitude and the inefficient power supply continues to generate the second DC supply voltage.

Abstract: A self-heating thermal protector operates to disconnect a load control device for a lighting load from an AC power source when insulation is present around the insulation detector independent of the magnitude of an AC mains line voltage of the AC power source. The insulation detector comprises a temperature-sensitive switch and a constant power circuit that are located in a thermally-conductive enclosure. The temperature-sensitive switch is coupled between the AC power source and the load control device and is rendered conductive and non-conductive in response to a temperature inside the enclosure. The constant power circuit is coupled in parallel with the AC power source and dissipates a constant amount of power independent of the magnitude of the AC mains line voltage when the temperature-sensitive switch is conductive. Restricted airflow over the thermal protector causes the temperature inside the enclosure to increase, such that the temperature-sensitive switch is rendered non-conductive.

Abstract: A system for configuring an output parameter of a lighting load power supply, the power supply having a programmable controller for regulating the output parameter to a target value and a memory for storing a variable for setting the target value. The power supply has a communication port for data for setting the target value. A computer executes software allowing a user to select a target value and provides data related to the selected parameter. A programming device in communication with the computer provides data relating to the selected parameter to the communication port for programming the controller to set the parameter to the target value.

Abstract: A system for configuring at least one output parameter of a lighting load power supply, the lighting load power supply having a programmable controller for regulating the output parameter to a target value and having a memory for storing a variable for setting the target value of the output parameter, the power supply having a communication port for receiving data for setting the target value, the system comprising a computer executing software allowing a user to select a target value of an output parameter of the lighting load power supply and having a first port providing data related to the selected output parameter; and a programming device having a second port in communication with the first port of said computer and for providing data relating to said selected output parameter in a form usable by said lighting load power supply to said communication port of said lighting load power supply for programming said programmable controller to set the output parameter to the selected target value.

Abstract: A converter for an LED driver for an LED light source. The converter has a flyback transformer. The primary receives a rectified AC voltage. A switching transistor is coupled in series with the primary. A controller controls the switching transistor on and off to generate a bus voltage across the secondary and a center tap voltage at a center tap of the secondary. The controller is powered by a first low-voltage DC voltage. A first power supply receives the center tap voltage and generates a second low-voltage DC voltage when the center tap voltage is above a cutover voltage. A second power supply has an output coupled to the first power supply output. The second power supply receives the bus voltage and generates the second DC voltage when the center tap voltage is below the cutover voltage.

Abstract: A configurable light-emitting diode (LED) driver is adapted to control a plurality of different LED light sources, which may be rated to operate using different load control techniques, different dimming techniques, and different magnitudes of load current and voltage. The LED driver comprises a power converter circuit for generating a DC bus voltage, and an LED drive circuit for receiving the bus voltage and adjusting either the magnitude of the current conducted through the LED light source or the magnitude of the voltage across the LED light source. The LED driver is operable to dim the LED light source using either a pulse-width modulation technique or a constant current reduction technique, and may be configured using a programming device and a personal computer.

Abstract: A light-emitting diode (LED) driver is adapted to control either the magnitude of the current conducted through a LED light source or the magnitude of a voltage generated across the LED light source. The LED driver comprises a power converter circuit for generating a DC bus voltage, and an LED drive circuit for receiving the bus voltage and adjusting the magnitude of the current conducted through the LED light source. The LED driver is operable to dim the LED light source using either a pulse-width modulation technique or a constant current reduction technique. The LED drive circuit may comprise a controllable-impedance circuit, such as a linear regulator. The LED driver may be operable to control the magnitude of the bus voltage to optimize the efficiency and reduce the power dissipation in the LED drive circuit, as well ensuring that the load voltage and current do not have any ripple.

Abstract: A load control circuit, such as a light-emitting diode (LED) driver, for controlling the amount of power delivered to an electrical load, such as an LED light source, comprises a regulation transistor adapted to be coupled in series with the load, and a feedback circuit coupled in series with the regulation transistor, whereby the load control circuit is able to control the magnitude of a load current conducted through the load from a minimum load current to a maximum load current, which is at least approximately one thousand times larger than the minimum load current. The feedback circuit generates at least one load current feedback signal representative of the magnitude of the load current. The regulation transistor operates in the linear region to control the magnitude of the load current conducted through the load in response to the magnitude of the load current determined from the load current feedback signal.

Abstract: A self-heating thermal protector operates to disconnect a load control device for a lighting load from an AC power source when insulation is present around the insulation detector independent of the magnitude of an AC mains line voltage of the AC power source. The insulation detector comprises a temperature-sensitive switch and a constant power circuit that are located in a thermally-conductive enclosure. The temperature-sensitive switch is coupled between the AC power source and the load control device and is rendered conductive and non-conductive in response to a temperature inside the enclosure. The constant power circuit is coupled in parallel with the AC power source and dissipates a constant amount of power independent of the magnitude of the AC mains line voltage when the temperature-sensitive switch is conductive. Restricted airflow over the thermal protector causes the temperature inside the enclosure to increase, such that the temperature-sensitive switch is rendered non-conductive.

Abstract: A converter for an LED driver for an LED light source. The converter has a flyback transformer. The primary receives a rectified AC voltage. A switching transistor is coupled in series with the primary. A controller controls the switching transistor on and off to generate a bus voltage across the secondary and a center tap voltage at a center tap of the secondary. The controller is powered by a first low-voltage DC voltage. A first power supply receives the center tap voltage and generates a second low-voltage DC voltage when the center tap voltage is above a cutover voltage. A second power supply has an output coupled to the first power supply output. The second power supply receives the bus voltage and generates the second DC voltage when the center tap voltage is below the cutover voltage.

Abstract: A system for configuring an output parameter of a lighting load power supply, the power supply having a programmable controller for regulating the output parameter to a target value and a memory for storing a variable for setting the target value. The power supply has a communication port for data for setting the target value. A computer executes software allowing a user to select a target value and provides data related to the selected parameter. A programming device in communication with the computer provides data relating to the selected parameter to the communication port for programming the controller to set the parameter to the target value.

Abstract: An electronic ballast having an inverter circuit for driving a gas discharge lamp prevents allows some hard switching to occur in the inverter circuit in order to ensure adequate ballasting impedance to provide stable operation of the lamp, but not enough hard switching to generate excessive power loss in the inverter circuit. The inverter circuit comprises two switching devices that are coupled in series between a DC bus voltage and circuit common and are rendered conductive on a complementary basis, such that a high-frequency output voltage is generated at the junction of the switching devices. When the intensity of the lamp is at or near a low-end intensity, an operating frequency of the high-frequency output voltage is controlled to a low-end frequency that is low enough to ensure stable operation of the lamp and to allow some hard switching to occur in the switching devices, but high enough to prevent excessive power loss due to the hard switching in the switching devices.

Abstract: A load control circuit, such as a light-emitting diode (LED) driver, for controlling the amount of power delivered to an electrical load, such as an LED light source, comprises a regulation transistor adapted to be coupled in series with the load, and a feedback circuit coupled in series with the regulation transistor, whereby the load control circuit is able to control the magnitude of a load current conducted through the load from a minimum load current to a maximum load current, which is at least approximately one thousand times larger than the minimum load current. The feedback circuit generates at least one load current feedback signal representative of the magnitude of the load current. The regulation transistor operates in the linear region to control the magnitude of the load current conducted through the load in response to the magnitude of the load current determined from the load current feedback signal.

Abstract: A light-emitting diode (LED) driver is adapted to control either the magnitude of the current conducted through a LED light source or the magnitude of a voltage generated across the LED light source. The LED driver comprises a power converter circuit for generating a DC bus voltage, and an LED drive circuit for receiving the bus voltage and adjusting the magnitude of the current conducted through the LED light source. The LED driver is operable to dim the LED light source using either a pulse-width modulation technique or a constant current reduction technique. The LED drive circuit may comprise a controllable-impedance circuit, such as a linear regulator. The LED driver may be operable to control the magnitude of the bus voltage to optimize the efficiency and reduce the power dissipation in the LED drive circuit, as well ensuring that the load voltage and current do not have any ripple.

Abstract: A configurable light-emitting diode (LED) driver is adapted to control a plurality of different LED light sources, which may be rated to operate using different load control techniques, different dimming techniques, and different magnitudes of load current and voltage. The LED driver comprises a power converter circuit for generating a DC bus voltage, and an LED drive circuit for receiving the bus voltage and adjusting either the magnitude of the current conducted through the LED light source or the magnitude of the voltage across the LED light source. The LED driver is operable to dim the LED light source using either a pulse-width modulation technique or a constant current reduction technique, and may be configured using a programming device and a personal computer.

Abstract: A multi-stage power supply for a load control device is able to operate in a low-power mode in which the power supply has a decreased power consumption when an electrical load controlled by the load control device is off. The load control device comprises a load control circuit and a controller, which operate to control the amount of power delivered to the load. The power supply comprises a first efficient power supply (e.g., a switching power supply) operable to generate a first DC supply voltage. The power supply further comprises a second inefficient power supply (e.g., a linear power supply) operable to receive the first DC supply voltage and to generate a second DC supply voltage for powering the controller. The controller controls the multi-stage power supply to the low-power mode when the electrical load is off, such that the magnitude of the first DC supply voltage decreases to a decreased magnitude and the inefficient power supply continues to generate the second DC supply voltage.

Abstract: An electronic ballast for a fluorescent lamp has a single-switch flyback inverter including a magnetizing inductance, a resonant circuit connected to the output of the inverter including a tank inductor, and a clamp circuit including a diode coupled to the primary winding of the flyback transformer for limiting the voltage across the magnetizing inductance when the switch is non-conductive. With the inverter switch conductive the resonant circuit has a first resonant frequency. With the inverter switch non-conductive, the resonant circuit, combined with the magnetizing inductance, has a second resonant frequency lower than the first. The magnetizing inductance is chosen such that the second resonant frequency is close to the first resonant frequency. The operating frequency of the inverter is controlled to be at or about the second resonant frequency, whereby zero current switching is achieved in the inverter switch.