A power supply apparatus including a power conversion circuit, a single transformer, a conjugate energy-storing inductor and a first and a second rectifying and filtering circuit is provided. The single transformer has a primary winding, a first secondary winding and a second secondary winding. The primary winding is coupled to the power conversion circuit and the first and second secondary windings respectively induce a corresponding voltage based on a voltage of the primary winding. The conjugate energy-storing inductor has a first and a second conjugate coil isolated from each other. The first and second rectifying and filtering circuits respectively charges/discharges in response to the voltage induced by the first and second rectifying and filtering circuits, and thereby respectively provides a first and a second output voltage via the output terminals of the first and second rectifying and filtering circuits.

Photographic lighting devices and systems having multiple electrical energy storage/discharge (EESD) elements and/or multiple light sources in a single photographic lighting device to perform one or more photographic lighting effects. In one exemplary aspect, independent control of one or more light sources connected to a first EESD bank and another one or more light sources connected to a second EESD bank, such as via control circuitry, may be utilized in producing various lighting effects.

Photographic lighting devices and systems having multiple electrical energy storage/discharge (EESD) elements and/or multiple light sources in a single photographic lighting device to perform one or more photographic lighting effects. In one exemplary aspect, independent control of one or more light sources connected to a first EESD bank and another one or more light sources connected to a second EESD bank, such as via control circuitry, may be utilized in producing various lighting effects.

A light fixture with multiple dimming capabilities is provided. More particularly, a device, system and method are provided for automatically sensing the presence of dimming signals from one or more power/voltage dimmers (i.e., phase-cut dimmers) and one or more data controllers providing dimming control signals according to a digital data controller protocol, and determining a priority between the two, for applying a dimming signal.

An emergency lighting system for an aircraft includes an emergency light control unit, having an external power input and at least one external control input for receiving external control commands from at least one of a cockpit crew, a cabin crew, a board computer and an autopilot, and a plurality of autonomous emergency light units, each of the plurality of autonomous emergency light units comprising at least one LED and a rechargeable capacitor. The emergency light control unit is configured to process the external control commands and to communicate emergency light control commands to the plurality of autonomous emergency light units as a response to the external control commands.

Drivers (10) for driving first and second light emitting diode circuits (1, 2) that produce first and second light may comprise first generators (11) for in response to ripple information generating first control signals and first controllers (12) for in response to the first control signals controlling first intensities of the first light such that a sum of the first and second intensities the first and second light is less fluctuating than each one of these intensities. The ripple information defines parameters of ripples resulting from rectifications of alternating-current signals. The drivers (10) may further comprise second generators (21) for in response to the ripple information generating second control signals and second controllers (22) for in response to the second control signals controlling the second intensities. Ripple based flickering is reduced and smaller capacitors can be used.

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.

A device includes a connection receiving power from a power source under normal conditions and circuitry configured to determine, based on an input from the connection, when the power from the power source is absent; output, when the power source is absent, a test signal at the connection; and generate a detection signal based on current flow generated following the output of the test signal, wherein the detection signal indicates a position of a switch connecting the circuitry to the connection and the generated detection signal indicates the switch is closed when the current flow is above a threshold. The circuitry is configured such that when the power from the power source is absent, the switch is closed, and plural devices are connected on the supply side of the switch, the plurality of devices on the supply side appear as a substantially open circuit to the test signal.

A device includes a connection receiving power from a power source under normal conditions and circuitry configured to determine, based on an input from the connection, when the power from the power source is absent; output, when the power source is absent, a test signal at the connection; and generate a detection signal based on current flow generated following the output of the test signal, wherein the detection signal indicates a position of a switch connecting the circuitry to the connection and the generated detection signal indicates the switch is closed when the current flow is above a threshold. The circuitry is configured such that when the power from the power source is absent, the switch is closed, and plural devices are connected on the supply side of the switch, the plurality of devices on the supply side appear as a substantially open circuit to the test signal.

A light-emitting diode (LED) tube lamp comprises a lamp tube, a first rectifying circuit, a filtering circuit and an LED driving module. The lamp tube has a first pin and a second pin for receiving an external driving signal. The first rectifying circuit is coupled to the first and second pins, for rectifying the external driving signal to produce a rectified signal. The filtering circuit is coupled to the first rectifying circuit, for filtering the rectified signal to produce a filtered signal. The LED driving module is coupled to the filtering circuit to receive the filtered signal for emitting light. Wherein, the filtering circuit includes a capacitor and an inductor connected in parallel and between one of the first and second pins and the first rectifying circuit, and the parallel-connected capacitor and inductor are configured for presenting a peak equivalent impedance to the external driving signal at a specific frequency.