摘要:
Devices (1) have branches (20,30) for receiving AC voltages. First branches (20) comprise first light-emitting diode circuits (21) and first arrangements for phase-shifting first currents flowing through the first light-emitting diode circuits (21) with respect to the AC voltages. Second branches (30) comprise second light-emitting diode circuits (31) and do not comprise second arrangements for phase-shifting second currents flowing through the second light-emitting diode circuits (31) with respect to the AC voltages. As a result, an overall flicker index of the device (1) will be smaller than individual flicker indices of the light-emitting diode circuits (21,31). The first arrangements may comprise capacitors (22) coupled serially to the first light-emitting diode circuits (21). The branches (20,30) may further comprise resistors (23,33) coupled serially to or forming part of the light-emitting diode circuits (21,31). The light-emitting diode circuits (21,31) generate light in response to positive and negative halves of the AC voltages.
摘要:
An input stage (10) of an apparatus (1) for driving a light-emitting diode (40-42) receives a signal from a power supply (30-32), and an output stage (20) supplies a current to the light-emitting diode (40-42). The peak value divided by the average value of the current forms a ratio. The driving efficiency is improved by providing the input stage (10) with an arrangement (11) for reducing this ratio by manipulation of the signal, without the necessity of using any smoothing capacitors/inductors. The manipulation may comprise an addition of a frequency component to the signal or an adaptation of an amplitude of a frequency component of the signal. This frequency component may be a third and/or fifth and/or seventh harmonic frequency component of a fundamental frequency component of the signal. The arrangement (11) may comprise a resonant tank which may need to be tuned to the frequency component of the signal.
摘要:
In an internal combustion engine with at least two groups of cylinders of which each has an exhaust pipe with a catalytic converter and of which one group can be shut down so that it is inoperative during part-load engine operation, the exhaust pipes are joined downstream of the catalytic converters by a common pipe section, and vacuum generating means are provided for subjecting the exhaust pipe of the inoperative cylinder group upstream of its catalytic converter during part load operation when the one cylinder group is shut down to vacuum for pulling exhaust gas from the common pipe section into the catalytic converter of the inoperative cylinder group.
摘要:
Driver device and a corresponding driving method for driving a load, in particular an LED assembly comprising one or more LEDs. To provide a better performance, better cost-efficiency, improved power factor and reduced losses, a driver device (1,1′, 2, 2′) is provided comprising a rectifier unit (10) for rectifying a received AC supply voltage (VS), load terminals (20) for providing a drive voltage (VL) and/or a drive current (IL) for driving said load, a capacitive storage unit (30) coupled between said rectifier unit and said load terminals for storing electrical energy provided by said rectifier unit and providing electrical energy to said load, and a bridge switching unit (40) coupled between said rectifier unit and said load for switching said capacitive storage unit into a load current path from said rectifier unit to said load terminals with a desired polarity and for switching said capacitive storage unit out of said load current path.
摘要:
The present invention relates to a driver device and a corresponding driving method for driving a load (22), in particular an LED unit, said driver device comprising power input terminals (51, 52) for receiving a periodic supply voltage from an external power supply potentially including a dimmer for dimming said periodic supply voltage,power output terminals (53, 54) for providing a drive voltage and/or drive current for driving a load (22), a power stage (70a, 70b, 70c, 70d) coupled between the power input terminals and the power output terminals for controlling an input current received from said power input terminals to draw a high power from said external power supply in a first mode or to draw a low or no power from said external power supply in a second mode, said high power being higher than the power required for driving said load and said low power being lower than the power required for driving said load, wherein said power stage controls said input current to be in the second mode only for a percentage of half cycle periods of a number of subsequent half cycle periods of said supply voltage, and for providing said drive voltage and/or drive current to said power output terminals in said first mode, and an energy storage unit (90) coupled to said power stage for storing electrical energy provided at said power input terminals in said first mode and for providing stored electrical energy to said load via said power output terminals in said second mode.
摘要:
Driver device and a corresponding driving method for driving a load, in particular an LED assembly comprising one or more LEDs. To provide a better performance, better cost-efficiency, improved power factor and reduced losses, a driver device (1,1′, 2, 2′) is provided comprising a rectifier unit (10) for rectifying a received AC supply voltage (VS), load terminals (20) for providing a drive voltage (VL) and/or a drive current (IL) for driving said load, a capacitive storage unit (30) coupled between said rectifier unit and said load terminals for storing electrical energy provided by said rectifier unit and providing electrical energy to said load, and a bridge switching unit (40) coupled between said rectifier unit and said load for switching said capacitive storage unit into a load current path from said rectifier unit to said load terminals with a desired polarity and for switching said capacitive storage unit out of said load current path.
摘要:
A light generating device (20) comprises: —an input for receiving a DC input voltage (Vin) of varying magnitude; —a controllable current source (40); —a switch matrix (30) comprising a plurality of controllable switches (S1-SN); —a plurality of n LEDs (D1, D2, . . . Dn) connected to output terminals of the switch matrix (30); —a controller (50) controlling said switches and controlling the current generated by the current source dependent on the momentary value of the DC input voltage (Vin). The controller is capable of operating in at least three different control states. In a first control state all LEDs are connected in parallel. In a second control state all LEDs are connected in series. In a third control state at least two of said LEDs are connected in parallel while also at least two of said LEDs are connected in series.
摘要:
The invention relates to a power supply system and a method for providing a load (L) with electrical power from either a first or a second AC grid source (10L, 10H) that supply different first and second AC voltages, respectively. In a particular example, said grid sources may belong to the US and the European mains, respectively, and the load may be a lamp with mains compatible LEDs (Ch1-Ch4). The power supply system comprises a first and a second connector device (30L, 30H) for connecting a converter circuit (20) to the first or the second AC grid source (10L, 10H), respectively. Moreover, the second connector device (30H) comprises a transformation circuit (D1-D4) for transforming the second AC voltage such that it yields a similar output voltage of the converter circuit (20) as the first AC voltage. In a particular example, the converter circuit (20) may comprise a rec tifier (D5-D8, C1, C2) with voltage doubling function, and the second connector device (30H) may comprise a rectifier (D1-D4) while the first connector device (30L) is a simple cable.
摘要:
A lamp assembly (1) comprises at least a light source (8) and a reflector for reflecting light from the light source (8). The reflector is positionable with respect to the light source (8) in at least a first position and a second position to obtain a spot-like light emission in the first position and a more or less omnidirectional light emission, in the second position, of the light emitted by the lamp assembly (1). The lamp assembly (1) comprises a reflective layer (7). In the first position of the reflector at least part of the light is reflected by the reflector as well as by the reflective layer (7). In the second position of the reflector at least part of the light is reflected by the reflector and passes along the reflective layer (7).
摘要:
A method for manufacturing a flooring product with integrated circuitry, comprising the steps of providing a plurality of pieces (6), stacking said pieces on top of each other, displaced in relation to each other to form an offset stack (10), and compressing said offset stack to form said flooring product. The method further comprises arranging flexible circuitry (7) on an upper surface of at least one piece, so that, when said pieces are stacked, a first portion (7a) of flexible circuitry on the at least one piece is exposed, said first portion (7a) including circuitry for interacting with the environment. By arranging the circuitry in the flooring during such a manufacturing process, a flooring product is achieved where only a portion of the circuitry is exposed, and another portion is embedded in the flooring. This allows for exposing those parts of the circuitry that are adapted to interact with the surrounding environment, such as optical components, pressure sensitive components, acoustic components, etc.