A lamp power supply realize 0 percent flicker and 0 flicker index with feedback setting the product of voltage and current of the lamp equal to the reference voltage times a constant.

A lighting device that properly controls light emission, thereby making it possible to perform product protection of the lighting device from generated heat without impairing usability. The lighting device is capable of using a plurality of types of batteries attached thereto, and includes a light emission section to which electric power is supplied from the attached battery. The lighting device includes a processor that functions as a light emission control unit configured to control light emission from the light emission section, and an acquisition unit configured to acquire information on the battery, including information on a temperature of the attached battery. A parameter for use in limiting light emission from the light emission section is determined based on a result of acquisition of the information on the battery.

An emergency power supply for lighting apparatuses and to a lighting apparatus for an emergency power supply. The emergency power supply (1) includes: a power supply (11) provided with at least one main insulation, e.g., transformer, (34), operatively connectable to the network voltage; an accumulator (16) operatively connected to the power supply (11); a flyback power converter (17) including a primary (18) and a secondary (19) provided within at least one additional insulation, e.g., transformer (30). The primary (18) is connected to the accumulator (16) and the secondary (19) is directly connectable, except for the conversion network, to the output of a network power supply (2) and simultaneously to a light source (3). A control unit (20), which includes an transistor activation device (27), is operatively connected to the power supply (11), to the accumulator (16) and to the primary (18) of the flyback power converter (17) and is configured for detecting the network voltage and for switching the emergency power supply (1) between a first mode of deactivation of the flyback power converter (17) and a second mode of activation of the flyback power converter (17).

A light emitting diode (LED) tube lamp includes a lamp tube; a first pin and a second pin coupled to a first end of the lamp tube, and a third pin coupled to a second end of the lamp tube; a first rectifying circuit comprising diodes and connected to the first and second pins, and a second rectifying circuit comprising diodes and connected to the third pin and an output terminal of the first rectifying circuit; a filtering circuit coupled to the two rectifying circuits and the LED module, for filtering the rectified signal to produce a filtered signal; an LED module comprising LEDs for emitting light, the LED module configured to be driven by the rectified signal or the filtered signal; and a driving circuit coupled between the two rectifying circuits and the LED module, and configured to drive the LED module. The LED tube lamp is configured to receive the external driving signal and emit light in each of two power supply arrangements, the two arrangements being respectively that the external driving signal is a low frequency signal input and transmitted through the first and second pins, and that the external driving signal is a low frequency signal input and transmitted through one of the first and second pins and the third pin across the two ends of the lamp tube. The LED tube lamp is configured such that when the received external driving signal is a low frequency signal, the LED tube lamp causes the rectified signal or the filtered signal to be used by the driving circuit for driving the LED module to emit light.

A two-way load control system comprises a power device, such as a load control device for controlling an electrical load receiving power from an AC power source, and a controller adapted to be coupled in series between the source and the power device. The load control system may be installed without requiring any additional wires to be run, and is easily configured without the need for a computer or an advanced commissioning procedure. The power device receives both power and communication over two wires. The controller generates a phase-control voltage and transmits a forward digital message to the power device by encoding digital information in timing edges of the phase-control voltage. The power device transmits a reverse digital message to the controller via the power wiring.

Introduced here are light sources for flash photography configured to produce high-fidelity white light that is tunable over a broader range of correlated color temperatures (CCTs) than conventional flash technologies. The light source can include multiple independently controllable color channels representing illuminants (e.g., light-emitting diodes) of different colors with varying degrees of saturation. Operating collectively, the multiple color channels can produce a high spectral quality white light corresponding to different CCTs (e.g., warm white light having a red hue, cool white light having a blue hue). Operating independently, these same color channels can be pre-flashed in a variety of prescribed sequences to probe the spectral characteristics of a scene, thereby allowing for an enhanced, spectrally matched white flash as well as collecting per-pixel reflectivity data that can be later used in during post processing of the captured image.

In an example, a circuit includes one or more switches, wherein the circuit is configured to receive a battery voltage from a battery, deliver an input voltage to a controller, deliver an output voltage, and receive signals from the controller. The signals may activate the one or more switches and deactivate the one or more switches and activating the one or more switches and deactivating the one or more switches may control the input voltage to the controller.

An LED tube lamp comprises a lamp tube, two end caps attached at two ends of the lamp tube respectively, a power supply disposed in one of the two end caps or separately in both of the end caps, an LED light strip disposed inside the lamp tube and a protective layer disposed on the LED light strip. The LED light strip comprises a mounting region and a connecting region. The plurality of LED light sources is mounted on the mounting region and two soldering pads are disposed on the connecting region. The mounting region and the connecting region are electrically connecting the plurality of LED light sources with the power supply. The protective layer comprises a plurality of first openings arranged on the mounting region for accommodating the LED light sources and two second openings are arranged on the connecting region for accommodating the two soldering pad.

A two-way load control system comprises a power device, such as a load control device for controlling an electrical load receiving power from an AC power source, and a controller adapted to be coupled in series between the source and the power device. The load control system may be installed without requiring any additional wires to be run, and is easily configured without the need for a computer or an advanced commissioning procedure. The power device receives both power and communication over two wires. The controller generates a phase-control voltage and transmits a forward digital message to the power device by encoding digital information in timing edges of the phase-control voltage. The power device transmits a reverse digital message to the controller via the power wiring.

Photographic lighting devices, systems, and methods having a plurality of electrical energy storage/discharge (EESD) elements and/or one or more light sources in a single photographic lighting device to perform one or more photographic lighting effects. EESD elements and one or more light sources can be configured to have multiple separate light emissions occur in a single image acquisition window. The multiple light emissions are separated in an image acquisition window by a time period that is about shutter speed exposure time/(N1), where N is the number of light emissions. In one such example, two light emissions are separated by a time period that is about shutter speed exposure time/(N1).