An LED lighting device includes an auxiliary power supply that supplies power to a control circuit of the LED lighting device that receives an input from a terminal of a light-emitting diode (LED) string of the lighting device that has a substantially lower voltage than the line voltage to which the lighting device is connected. The terminal may be within the LED string, or may be an end of the string. A linear regulator may be operated from the voltage drop across a number of the LEDs in the string so that the energy wasted by the auxiliary power supply is minimized. In other designs, the auxiliary power supply may be intermittently connected in series with the LED string only when needed. The intermittent connection can be used to forward bias a portion of the LED string when the voltage supplied to the LED string is low, increasing overall brightness.

An embedded device 105 is assembled within a flexible circuit assembly 30 with the embedded device mid-plane intentionally located in proximity to the flexible circuit assembly central plane 115 to minimize stress effects on the embedded device. The opening 18, for the embedded device, is enlarged in an intermediate layer 10 to enhance flexibility of the flexible circuit assembly.

A conformal power adapter for insertion into a lighted artificial tree and for converting power received from an external power source to a power usable by the lighted artificial tree. The power adapter includes an elongated housing including a first end, and a second end; a printed circuit board assembly including power-converting circuitry for converting an input electrical power to an output electrical power for use by a lighted artificial tree having a hollow trunk section, the printed circuit board assembly located substantially within the elongated housing; a power cord secured to the first end of the housing and in electrical connection with the power converting electronics, the power cord adapted to transmit power from an external power source to the power-converting circuitry. The elongated housing enclosing the printed circuit board assembly is sized to fit substantially within the hollow trunk portion of the lighted artificial tree.

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.

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.

An arrangement and a method for controlling a plurality of light emitting diodes which are connected in series to attain uniform distribution of a total current to several series connections, LED chains, connected in parallel to each other wherein circuitry-related expenditure and power losses occurring during the control process are minimized, include a first reference voltage generating unit and a second reference voltage generating unit, wherein a outlet of the first reference voltage generating unit is connected to a first and a second control circuit, and an outlet of the second reference voltage generating unit is connected to the second and the first control circuit, and an outlet of the first control circuit is connected to a control inlet of the first controllable semiconductor switch, and an outlet of the second control circuit is connected to a control inlet of the second controllable semiconductor switch.

In some examples, automatic light fixture address technology includes methods and apparatuses. In other examples, the method includes receiving a disable forward control command to disable data forwarding through the light fixture; receiving an enable forward control command to enable data forwarding through the light fixture; transmitting address data for the light fixture based on the enable forward control command; and forwarding one or more additional enable forward control commands based on the enable forward control command.

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.

In some embodiments, a light source including a first electrode that includes a projection and a depression, a second electrode including a projection and a depression, an insulating layer disposed between the first electrode and the second electrode, and a light-emitting element straddling the insulating layer and disposed on the projection of the first electrode and on the projection of the second electrode. In other embodiments, a lighting device including a base that includes a first terminal and a second terminal that are configured to be electrically connected to the light source to supply current to the light-emitting element. In some embodiments, the lighting device is a lighting bulb, and in other embodiments, the lighting device is tube-shaped.

In various embodiments a device and method for providing power to an LED unit and modulating light emitted from the LED unit is disclosed. In one example, the device is configured to be connected between a driver and the LED unit. In this example, the device comprises a controllable resistor that receives from the driver a driver output voltage and to provides a load current to power the LED unit, a frequency filter for providing a substantially constant voltage to the LED unit, the frequency filter being connected to the controllable resistor to provide a substantially constant electrical power to the LED unit, and a modulator coupled in series to the LED unit for modulating the drive current and for modulating the emitted light output, wherein the substantially constant voltage applied to the LED unit is further applied to the modulator by means of the frequency filter.