Abstract: A load control device, such as an electronic ballast, for controlling the power delivered from an AC power source to an electrical load, such as one or more fluorescent lamps, comprises a power converter having an inductor and a power switching device coupled to the inductor, a load control circuit adapted to be coupled to the electrical load, and a control circuit operable to calculate an average input power of the load control device. The control circuit may be operable to calculate a cumulative output power of the power converter while the ballast is preheating filaments of the lamps, and to subsequently determine a fault condition in the lamps in response to the calculated cumulative output power of the power converter. Further, the control circuit may be operable to transmit a digital message including the calculated average input power of the load control device.

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: An electronic ballast for driving a gas discharge lamp includes a power converter for generating a DC bus voltage, where the bus voltage is controlled to different magnitudes during different operating modes of the ballast. The ballast comprises a control circuit that is coupled to the power converter for adjusting the magnitude of the bus voltage to a first magnitude when the lamp is off, to a second magnitude when preheating filaments of the lamp, and to a third magnitude when the lamp is on. The control circuit is also operable to preemptively adjust the magnitude of the bus voltage prior to changing modes of operation. For example, when turning the load on, the control circuit first adjusts a power-conversion-drive level of the power converter to begin adjusting the magnitude of the bus voltage towards a predetermined magnitude, and then waits for a predetermined time period before attempting to turn the load on.

Abstract: A method of controlling a light level in a space of a building, the method comprising the steps of measuring the light level in the space; automatically adjusting the light level in the space towards a control setpoint; receiving an input to manually override the light level in the space to an override light level; adjusting the light level in the space to the override light level; temporarily adjusting the control setpoint from a default setpoint to a temporary setpoint in response to the manual override of the light level, the temporary setpoint representative of the override light level; subsequently adjusting the control setpoint from the temporary setpoint back to the default setpoint; and adjusting the default setpoint in response to repeated manual overrides of the light level that result in repeated adjustments of the control setpoint.

Abstract: A ballast for use in a multi-ballast lighting system wherein the ballasts are coupled together by a digital communication network. The ballast comprises a power circuit portion for providing an electrical current to power a lamp. The ballast further includes a sensor input circuit for receiving at least one sensor input from a sensor device, a processor receiving an input from the sensor input circuit and providing control signals to control the operation of the ballast, and a communication port coupled to the processor and to the communication network for exchanging data. The ballast processor is operative to receive a serial data that has a portion defining whether the message is in a first or a second format, the first format comprising a DALI standard format and the second format comprising a format providing extended functionality. The ballast processor is capable of processing messages in either the first or second formats.

Abstract: An electronic ballast circuit for driving a gas discharge lamp is operable to control the lamp to avoid flicking and flashing of the intensity of the lamp during low temperature conditions. The ballast circuit includes an inverter circuit for receiving a DC bus voltage and for generating a high-frequency output voltage, a resonant tank circuit for receiving the high-frequency output voltage and generating a sinusoidal voltage for driving said lamp, and a control circuit operatively coupled to the inverter circuit for adjusting an intensity of the lamp between a minimum intensity and a maximum intensity. The control circuit receives a control signal representative of a lamp temperature of the lamp, and increases the minimum intensity of the lamp if the lamp temperature of the lamp drops below a cold temperature threshold. In addition, the ballast circuit may also include a temperature sensing circuit operable to generate the control signal representative of the lamp temperature of the lamp.

Abstract: A communication circuit for an electronic dimming ballast provides high-voltage miswire protection and improved rise and fall times of a transmitted digital signal. The electronic dimming ballast comprises a control circuit, which is coupled to a digital communication link, for example, a DALI communication link, via the communication circuit. The communication circuit comprises a receiving circuit for detecting when the digital ballast communication link is shorted and for providing a received digital message to the control circuit. The communication circuit also comprises a transmitting circuit for shorting the communication link in response to the control circuit. The communication circuit also includes a high-voltage fault protection circuit for protecting the circuitry of the communication circuit if the communication circuit high-voltage mains voltages. The communication circuit is operable to reliably transmit digital messages having improved rise and fall times.

Abstract: A system for reducing sun glare through an opening into a space, the system comprising an electrically controllable window treatment operable to alter the amount of daylight entering the space through the opening; a first sensor mounted within the space and characterized by a sensor gain, the first sensor operable to sense a level of illumination in the space; and a control system operable: to compare the sensed illumination level in the space to a dead-band having upper and lower thresholds; to adjust during a time period when glare from the sun can occur through the opening at least one of: (a) the upper threshold of the dead-band, (b) the lower threshold of the dead-band, and (c) the sensor gain of the first sensor; and to adjust the window treatment in response to the sensed level of illumination to reduce the sun glare.

Abstract: A system for reducing sun glare through an opening into a space, the system comprising an electrically controllable window treatment operable to alter the amount of daylight entering the space through the opening; a first sensor mounted within the space and characterized by a sensor gain, the first sensor operable to sense a level of illumination in the space; and a control system operable: to compare the sensed illumination level in the space to a dead-band having upper and lower thresholds; to adjust during a time period when glare from the sun can occur through the opening at least one of: (a) the upper threshold of the dead-band, (b) the lower threshold of the dead-band, and (c) the sensor gain of the first sensor; and to adjust the window treatment in response to the sensed level of illumination to reduce the sun glare.

Abstract: The invention regards a system and method for using a handheld programming device to configure a lighting control system wirelessly. In one embodiment, at least one device configured with a processing section is installed in the lighting control system. A communications receiver that is operable to receive a signal from the handheld programming device is also installed in the lighting control system, wherein the signal includes an instruction for configuring the lighting control system. Further, the signal is wirelessly sent from the handheld programming device to the communications receiver, and the instruction is transmitted from the communications receiver to a device in the system. The instruction functions to configure the lighting control system.

Abstract: The invention regards a system and method for using a handheld programming device to configure a lighting control system wirelessly. In one embodiment, at least one device configured with a processing section is installed in the lighting control system. A communications receiver that is operable to receive a signal from the handheld programming device is also installed in the lighting control system, wherein the signal includes an instruction for configuring the lighting control system. Further, the signal is wirelessly sent from the handheld programming device to the communications receiver, and the instruction is transmitted from the communications receiver to a device in the system. The instruction functions to configure the lighting control system.

Abstract: A ballast for use in a multi-ballast lighting system wherein the ballasts are coupled together by a digital communication network. The ballast comprises a power circuit portion for providing an electrical current to power a lamp. The ballast further includes a sensor input circuit for receiving at least one sensor input from a sensor device, a processor receiving an input from the sensor input circuit and providing control signals to control the operation of the ballast, and a communication port coupled to the processor and to the communication network for exchanging data. The ballast processor is operative to receive a serial data that has a portion defining whether the message is in a first or a second format, the first format comprising a DALI standard format and the second format comprising a format providing extended functionality. The ballast processor is capable of processing messages in either the first or second formats.

Abstract: An electronic dimming ballast comprises a filament turn-off circuit for controlling the magnitudes of filament voltages supplied to the filaments of a gas discharge lamp. Each of a plurality of filament windings is directly coupled to one of the filaments and is operable to supply a small AC filament voltage to the filaments. The plurality of filament windings and a control winding are loosely magnetically coupled to a resonant inductor of an output circuit of the ballast. A controllably conductive device is coupled across the control winding. When the controllably conductive device is conductive, the voltage across the control winding and the filament windings falls to zero volts. The controllably conductive device is driven with a pulse-width modulated (PWM) signal so as to control the magnitudes of the filament voltages. The filament voltages are provided to the filaments before striking the lamp, and when dimming the lamp near low end.

Abstract: An electronic ballast for driving a gas discharge lamp includes a rectifier to convert an AC mains input voltage to a rectified voltage, a filter circuit for producing a DC bus voltage, an inverter for converting the bus voltage to a high-frequency AC voltage for driving the lamp, an output circuit for supplying an essentially sinusoidal voltage to the lamp, a control circuit for controlling the inverter, and a flyback cat-ear power supply for powering the control circuit. The power supply supplies current to the inverter when the rectified voltage is less than a predetermined level, and draws current only when the inverter is not drawing current directly from the AC mains, so as to make the input current to the ballast substantially sinusoidal. The ballast thus has substantially improved power factor and THD, and operates more efficiently.

Abstract: A communication circuit for an electronic dimming ballast provides high-voltage miswire protection and improved rise and fall times of a transmitted digital signal. The electronic dimming ballast comprises a control circuit, which is coupled to a digital communication link, for example, a DALI communication link, via the communication circuit. The communication circuit comprises a receiving circuit for detecting when the digital ballast communication link is shorted and for providing a received digital message to the control circuit. The communication circuit also comprises a transmitting circuit for shorting the communication link in response to the control circuit. The communication circuit also includes a high-voltage fault protection circuit for protecting the circuitry of the communication circuit if the communication circuit high-voltage mains voltages. The communication circuit is operable to reliably transmit digital messages having improved rise and fall times.

Abstract: A method of automatically programming a new load control device that replaces an old load control device takes advantage of a remote identification tag (e.g., an RFID tag) located in the vicinity of the old device. The remote identification tag stores an identifier that is representative of a location in which the old device is installed. The method includes the steps of: (1) storing a setting of an old device in a memory of a controller; (2) associating the setting with the identifier of the old device in the memory of the controller; (3) the new device retrieving the identifier from the remote identification tag after the new device is installed in the location of the old device; (4) the new device transmitting the identifier to the controller; and (5) the controller transmitting the setting of the old device to the new device in response to receiving the identifier.

Abstract: The invention regards a system and method for using a handheld programming device to configure a lighting control system wirelessly. In one embodiment, at least one device configured with a processing section is installed in the lighting control system. A communications receiver that is operable to receive a signal from the handheld programming device is also installed in the lighting control system, wherein the signal includes an instruction for configuring the lighting control system. Further, the signal is wirelessly sent from the handheld programming device to the communications receiver, and the instruction is transmitted from the communications receiver to a device in the system. The instruction functions to configure the lighting control system.

Abstract: A communication circuit for an electronic dimming ballast provides high-voltage miswire protection and improved rise and fall times of a transmitted digital signal. The electronic dimming ballast comprises a control circuit, which is coupled to a digital communication link, for example, a DALI communication link, via the communication circuit. The communication circuit comprises a receiving circuit for detecting when the digital ballast communication link is shorted and for providing a received digital message to the control circuit. The communication circuit also comprises a transmitting circuit for shorting the communication link in response to the control circuit. The communication circuit also includes a high-voltage fault protection circuit for protecting the circuitry of the communication circuit if the communication circuit high-voltage mains voltages. The communication circuit is operable to reliably transmit digital messages having improved rise and fall times.

Abstract: A method of determining a setpoint of a load control device for controlling the amount of power delivered to an electrical load located in a space, the method comprising the steps of initially setting the value of the setpoint equal to a desired level; limiting the value of the setpoint to an occupied high-end trim if the space is occupied; limiting the value of the setpoint to a daylighting high-end trim determined by a daylighting procedure; and subsequently reducing the value of the setpoint in response to a load shed parameter.

Abstract: A method of determining a setpoint of a load control device for controlling the amount of power delivered to an electrical load located in a space, the method comprising the steps of initially setting the value of the setpoint equal to a desired level; limiting the value of the setpoint to an occupied high-end trim if the space is occupied; limiting the value of the setpoint to a daylighting high-end trim determined by a daylighting procedure; and subsequently reducing the value of the setpoint in response to a load shed parameter.