A compatible inductor-type circuit structure with direct input from commercial power includes a substrate and a light-source control-loop device. The light-source control-loop device is disposed on the substrate and includes a constant current circuit, plural light source modules, a switch, a commercial power simulation circuit, a high voltage protection circuit, plural bridge rectifier circuits and a limited current protection circuit. The constant current circuit, the light source modules, the switch, the commercial power simulation circuit, the high voltage protection circuit, the bridge rectifier circuits and the limited current protection circuit are connected together electrically. By the abovementioned structures, a luminaire can be installed directly on any lamp holder, without considering whether to remove the ballast. The circuit structure can be compatible with a dedicated LED lamp holder or a lamp holder activated by a ballast, thereby facilitating the usage.

Power consumption in a start-up circuit for a LED-based light bulb may be reduced by digitally switching a transistor of the start-up circuit coupled to the input voltage. When the transistor is digitally switched between on and off, a reduced amount of power is dissipated by the transistor, because it may not enter a saturation region of operation where the resistance of the transistor between drain and source terminals increases. The transistor may be coupled to a voltage regulator for generating one or more output voltages, including a supply voltage for a host controller IC. The transistor may be switched on and off by a digital signal generated by logic circuitry, which may decide to switch the transistor on and off based on a voltage level at an output of the voltage regulator.

A load control system may include a load control device for providing power to an electrical load and a control device that may send instructions to the load control device for providing the power to the electrical load. The control device may communicate with the load control device using a link address assigned to the load control device. The load control device may provide power to the electrical load in a manner that causes the electrical load to indicate the link address assigned to the load control device. The link address may be identified by a user or a user device. The identified link address may be associated with a load control device identifier that may identify a physical location of a load control device that is assigned the link address. A user may control a load control device at a physical location by sending instructions via the link address.

A circuit arrangement for operating at least a first and a second cascade of LEDs is provided including an input having a first and a second input connection for coupling to a rectified AC supply voltage, a voltage equalization series impedance, and at least a higher and a lower LED units which include cascades. The connection of the LED cascade that is not coupled to a first diode is a second node, and the second node of the lowest LED unit is coupled to a voltage equalization series impedance such that the impedance is coupled in series between the second node and the second input connection. In not-the-lowest LED unit, a fourth node is at any rate a node of the circuit arrangement that is at a lower potential, at least during a prescribable period during the circuit arrangement operation, than the second node.

Arrangements comprise drivers (1) for driving light circuits (5), receivers (2) for in response to receptions of wireless signals controlling the drivers (1), and supplies (3) for providing first feeding signals for feeding the receivers (2) during off-states of the drivers (1). The drivers (1) themselves provide second feeding signals for feeding the receivers (2) during on-states of the drivers (1). Devices (6) such as lamps in the form of retrofit tubes comprise the arrangements and the light circuits (5). The light circuits (5) may comprise light emitting diodes. The arrangements may receive AC signals from ballasts (7), and both feeding signals may be DC signals. The supplies (3) may comprise voltage dividers (31, 32) with first capacitor circuits (31) to limit currents entering the supplies (3) for given frequencies of the AC signals and voltage definition circuits (32) for defining voltage signals present across the voltage definition elements (32). Both feeding signals may be supplied via elements (33, 35) with diode functions.

A light emitting diode lighting assembly that receives an electrical excitation signal that is varied from a dimming device. Driving circuitry receives the varying input and has first and second paths that each have a plurality of light emitting diodes. Each plurality of light emitting diodes has a threshold voltage with the threshold voltage of the first plurality of diodes being less than the threshold voltage of the second plurality of lighting emitting diodes. The current within the first path is controlled by a current limiting device that is controlled by a resistor that receives input from the second path to gradually turn off the first plurality of light emitting diodes as the second plurality of lighting emitting diodes increase in intensity. A shunt voltage regulator within the circuit having a threshold voltage that is above threshold voltages of components in the assembly to minimize voltage increases in the assembly.

A method for increasing battery life in a lighting device powered by a battery source in which an electronic switch is caused to provide a declining power supply to a light emitting diode (LED) as a power profile of the battery source declines.

A lighting device (100) is provided comprising optically transmissive emitters and receivers. The receivers are configured to receive power via an optical signal transmitted from a light source (102). Furthermore, the receiver is provided with functionality for converting the optical signal to electrical power and supply an emitter with the electrical power. The optical signal may further comprise an address such that a receiver-emitter pair of the device may be wirelessly individually addressed and controlled. The optical signals of the device are not guided but are free to propagate through optically transmissive receivers, optically transmissive emitters or other optically transmissive materials of the lighting device. This enables a lighting device which provides new light effects in a simple manner.

An improved lighting apparatus is disclosed. The lighting apparatus includes a direct current power supply unit, a light emitting unit operating in response to a direct current voltage applied from the direct current power supply unit, and a voltage control unit located between the direct current power supply unit and the light emitting unit to control the level of a voltage applied from the direct current power supply unit to the light emitting unit. The light emitting unit includes first light emitting groups having a first correlated color temperature and being turned on at a first turn-on voltage (V.sub.B) or above and second light emitting groups having a second correlated color temperature and being turned on at a second turn-on voltage (V.sub.A) greater than the first turn-on voltage. The first light emitting groups are connected in parallel with the second light emitting groups. The voltage control unit includes at least one variable resistor to control the level of the voltage applied to the light emitting unit such that the second light emitting groups emit light or are prevented from emitting light, achieving a desired correlated color temperature according to a preset proportion.

A resonant inductive coupling extension cord and light emitting diode system having a plurality of light emitting diodes (LEDS) connected to a receiver coil designed to receive a pulsed DC current from a power supply by means of resonant inductive coupling. The power supply generates a pulsed DC current at a frequency of 0.8 KHz or greater, wherein the pulsed DC current is positive relative to ground. The power supply provides the pulsed DC current through a power coil and through the extension cords to the receiver coil. The (LEDs) are powered through resonant inductive coupling up to 160 volts. The light emitting diodes are self-limiting with respect to current. There is no potential for a spark or shock hazard when the extension cords are connected to the power supply, to the LED system or each other or whether the extension cords or LED are cut or broken.