The invention relates to power supply systems. There is provided an apparatus and a method for supplying electric power to an electric device. In the method an indication of a desired power level to be supplied to the electric device is obtained. Electric power is received as DC power by a constant current regulator unit, which inverts the DC power to AC power and supplies the AC power to a reactance (T1) to be transformed to an output power. The output power is supplied from the reactance (T1) to the electric device. The method further comprises adjusting the AC power supplied to the reactance (T1) by using at least two of the following: voltage level of the AC power; the frequency of the AC power; a waveform of the AC power.

The invention relates to power supply systems. There is provided an apparatus and a method for supplying electric power to an electric device. In the method an indication of a desired power level to be supplied to the electric device is obtained. Electric power is received as DC power by a constant current regulator unit, which inverts the DC power to AC power and supplies the AC power to a reactance (T1) to be transformed to an output power. The output power is supplied from the reactance (T1) to the electric device. The method further comprises adjusting the AC power supplied to the reactance (T1) by using at least two of the following: voltage level of the AC power; the frequency of the AC power; a waveform of the AC power.

An illumination lighting apparatus is configured to light a plurality of light-emitting elements connected in series to each other. The illumination lighting apparatus includes one photosensor and a detector. The one photosensor is configured to detect light emitted from the plurality of light-emitting elements. The detector is configured to perform detection of a light emission defect on the plurality of light-emitting elements based on the light detected by the one photosensor. Moreover, the detector performs the detection process when a quantity of light detected by the one photosensor decreases. The detector includes two or more switches and a processor. The two or more switches are connected in parallel to the plurality of light-emitting elements. When the processor turns on the two or more switches sequentially one-by-one, and the quantity of light detected by the one photosensor does not change, the processor detects a light-emitting element having the light emission defect from the plurality of light-emitting elements.

An illumination lighting apparatus is configured to light a plurality of light-emitting elements connected in series to each other. The illumination lighting apparatus includes one photosensor and a detector. The one photosensor is configured to detect light emitted from the plurality of light-emitting elements. The detector is configured to perform detection of a light emission defect on the plurality of light-emitting elements based on the light detected by the one photosensor. Moreover, the detector performs the detection process when a quantity of light detected by the one photosensor decreases. The detector includes two or more switches and a processor. The two or more switches are connected in parallel to the plurality of light-emitting elements. When the processor turns on the two or more switches sequentially one-by-one, and the quantity of light detected by the one photosensor does not change, the processor detects a light-emitting element having the light emission defect from the plurality of light-emitting elements.

A display may have display layers that form an array of pixels. The array of pixels may be illuminated using a backlight unit. The backlight unit may include multiple strings of light-emitting diodes (LEDs). The multiple LED strings may be controlled by one or more backlight driver integrated circuits (ICs). In a multi-driver IC architecture, an enable signal may be used to set a desired phase delay between the multiple ICs. One or more of the LED strings may exhibit a short fault. Depending on the number of faulty LED strings, the backlight unit can selectively throttle the maximum brightness of the display. The LED strings may receive an output voltage from a DC/DC converter and may be driven using a current driver. The DC/DC converter may be controlled by a headroom feedforward control circuit to ensure sufficient headroom for the current driver while suppressing acoustic noise.

An illumination lighting apparatus is configured to light a plurality of light-emitting elements connected in series to each other. The illumination lighting apparatus includes one photosensor and a detector. The one photosensor is configured to detect light emitted from the plurality of light-emitting elements. The detector is configured to perform detection of a light emission defect on the plurality of light-emitting elements based on the light detected by the one photosensor. Moreover, the detector performs the detection process when a quantity of light detected by the one photosensor decreases. The detector includes two or more switches and a processor. The two or more switches are connected in parallel to the plurality of light-emitting elements. When the processor turns on the two or more switches sequentially one-by-one, and the quantity of light detected by the one photosensor does not change, the processor detects a light-emitting element having the light emission defect from the plurality of light-emitting elements.

Programmable drivers (or power supplies) for solid state light sources are disclosed, on which output regulation is improved to expand the dimming range to 1% and reduce and/or remove flicker. Additional fault conditions are set up to avoid latching, and thus provide for a controllable restart feature. Such drivers include an isolated half bridge resonant converter with an improved control approach designed to regulate very low current though primary side in a feed-forward loop. Such drivers include both digital and analog loops that improve the performance in steady state and/or during transients, particularly for a lighting load, in comparison to a single full digital control.

A resistor bypass circuit for a series lighting circuit includes a plurality of serially connected light sources and a bypass resistor being connected in parallel with at least one of the respective light sources, each respective light source being low wattage and being capable operating on a one hundred percent duty cycle as desired.

A bridge circuit (22) includes a first light-emitting element group (102, 110) and a second light-emitting element group (103, 120) connected in series; and a pair of comparison resistors (201, 202) connected in series and generating a voltage (Vref) equivalent to a voltage (VLED) at a connecting point between the first light-emitting element group (102, 110) and the second light-emitting element group (103, 120). A transistor (301, 302) is connected to a connecting point between the first light-emitting element group (102, 110) and the second light-emitting element group (103, 120) and a connecting point between the comparison resistors (201, 202), and operates when the first light-emitting element group (102, 110) or the second light-emitting element group (103, 120) is short-circuited.

A device, system, and method determine addresses of nodes for an arrangement including strings that have nodes and a splitter. The system includes a controller device connected to a first string, the first string also connected to the splitter. The system includes a bus configuration connecting the nodes to one another and to the controller device. The controller device transmits first signals to the nodes of the first string and sequentially receives first responses. The controller device assigns addresses to the nodes of the first string. The controller device generates a second signal that defines a path to a splitter output. The controller device sequentially receives second responses from nodes of a second string on the splitter output and then assigns addresses to the nodes of the second string.