To prevent image retention, the pixel circuit includes: a light emitting element; a driving transistor which supplies an electric current according to an applied voltage to the light emitting element; a capacitor part which holds the voltage containing a threshold voltage and a data voltage of the driving transistor; and a switch part which has the voltage containing the threshold voltage and the data voltage held to the capacitor part and applies the voltage to the driving transistor. Further, the switch part has a function which applies a constant voltage to the driving transistor before having the voltage containing the threshold voltage and the data voltage held to the capacitor part.

A sensor, such as a motion sensor and/or an occupancy sensor, can include the capability of communicating wirelessly with a user device such that sensor settings can be adjusted via an application running on the user device. The sensor settings may determine when one or more light sources (e.g., a light fixture, a light bulb, a light emitting diode (LED), etc.) turn on and/or the amount of light produced by the one or more light sources.

In some embodiments of the disclosed subject matter, systems and methods for controlling aquatic lighting using power line communication are disclosed. In some embodiments, the system includes a lighting controller configured to receive power via an AC power line, the lighting controller comprising a light driver circuit configured to be coupled to at least one light source, a first power line modem configured to be connected to a local area network via a second powerline modem and the AC power line, and a processor that is configured to receive, from a user interface via the first power line modem, lighting data corresponding to a lighting selection specified by user input received by the user interface and cause the light driver circuit to drive the at least one light source to present the lighting selection based on the lighting data.

A dimmable LED module configured for electrical connection with an AC mains power supply via a switch (9), the dimmable lighting module including a plurality of activatable LED light sources configured for emitting a corresponding lighting characteristic when activated, and, a control unit (4) configured for selectably activating at least one of the plurality of LED light sources in response to a control signal generated by a predetermined switching operation of the switch (9) that is received by the control unit (4) such that a plurality of lighting modes are able to be selectably output from the dimmable LED module corresponding to the at least one of the plurality of LED light sources that are selectably activated by the control unit (4), the plurality of lighting modes being indicative of a resulting lighting characteristic emitted by the at least one of the plurality of selectably activated LED light sources corresponding to the lighting modes, wherein the plurality of lighting modes include at least a first lighting mode and a second lighting mode whereby the second lighting mode is indicative of a resulting lighting characteristic that is relatively dimmed compared to that of the first lighting mode.

A dual-output power adapter for a lighted artificial tree having a plurality of tree portions with light strings having lighting elements. The dual-output power adapter includes a power cord including a first power conductor and a second power conductor, the power cord configured to transmit an input electrical power; a housing configured to receive the first power conductor and a second power conductor; power-converting circuitry in electrical connection with the first power conductor and the second power conductor, the power-converting circuitry configured to convert the input electrical power to a first output electrical power; a first pair of conductors for transmitting the first output electrical power; and a second pair of conductors for transmitting a second output electrical power.

This invention relates to a method of controlling the light output of a solar-powered lighting device. The lighting device comprises a light source, a battery connected to the light source, a solar-power generator including a charger connected to the battery, and a control unit for performing the light output control. The method comprises: charging the battery while solar-power is generated; acquiring local day-light data; repeatedly: acquiring, at predetermined time intervals, local weather forecast data covering a predetermined time period, and determining a lighting output profile for the predetermined time period; and driving the lighting device according to the lighting output profile, wherein said determining a lighting output profile comprises: predicting a lighting demand for the predetermined time period on basis of first environment light data, which first environment light data comprises the local day-light data; predicting a battery capacity for the predetermined time period on basis of a present energy storage level and second environment light data, which second environment light data comprises the weather forecast data and the local day-light data; and determining the lighting output profile on basis of the lighting demand and the battery capacity under consideration of keeping the energy storage level above a predetermined minimum level during the predetermined time period.

Embodiments are provided for a lighting system and a method of installing a lighting system. According to certain aspects, a driver box is configured with a plurality of drivers secured therein. A series of wired connections can couple the plurality of drivers to a plurality of luminaires and can conduct electric power from the plurality of drivers to power the plurality of luminaires. According to aspects, the driver box and its plurality of drivers are located remote from the plurality of luminaires to enable efficient maintenance of the lighting system.

A multi-port communications gateway for one or more LED based illumination devices includes a lighting communications interface that is configured to be coupled to the LED based illumination device(s). The lighting communications interface transmits both data signals and power signals. A lighting control network interface is configured to be coupled to a lighting control system, which generates control commands. A building management network interface is configured to be coupled to a building management system and is configured to receive and transmit information from sensors coupled to the LED based illumination device(s). Memory in the gateway stores information received from the LED based illumination device (s). A processor determines a summary status value associated with the LED based illumination device(s) based on information stored in memory. A real time clock determines a date and time that is periodically transmitted to the LED based illumination device(s).

A lighting control system includes control devices each configured to be coupled with one or more lighting devices. Each of the control devices includes sensor(s) configured to measure a characteristic of an environment, and hardware circuitry configured to connect with a network for one or more of remotely controlling operation of the one or more lighting devices, communicating the characteristic that is sensed, or monitoring information received through the network. The hardware circuitry of the control devices are configured to operate between different operational modes to perform different functions to control the one or more lighting devices based on the characteristic that is measured by the one or more sensors, based on the information received via the network, or based on both the characteristic that is measured and the information received via the network. The system also includes switching hardware configured to change the operational mode of the control devices.

A method and circuit for driving an LED lighting device from an AC power source includes a rectifier and a plurality of strings of LEDs. Each string of LEDs includes a plurality of LEDs. A plurality of switches is controlled by a controller for opening and closing the switches. The controller is adapted to vary the number of strings conducting electricity by applying voltage from the rectifier to arrangements of the plurality of strings of LEDs selected based upon the present voltage of the output of the rectifier and the forward bias voltage of each of the strings of LEDs.