摘要:
A lighting system for improving the alertness of a person comprising: one or more light sources (101) arranged to emit light into an environment, at least one of the one or more light sources being arranged with a primary function comprising providing illumination into the environment; and a controller (103) configured to cause at least one of the at least one light sources to provide a secondary function of emitting at least a first light pulse (503) having a duration of between 1 ms and 50 ms, wherein there is an idle period (505) lasting at least 0.1 s on either side of the first light pulse.
摘要:
A light unit (10) including one or more lighting devices, in particular one or more LEDs is disclosed. The light unit comprises input terminals (12, 14) for connecting the light unit to an external power supply (16) and for receiving an input voltage (V10) from the external power supply. A first lighting device and at least one additional lighting device (22, 24) connected in series to the input terminals and a charge storage device (26) is connected in series to the first lighting device. The first lighting device (20) and the additional lighting device (22, 24) forms a tapped linear driver that the number of the lighting device (20, 22, 24) being turned on depending on an amplitude of the input voltage (V10). The first lighting device or a second lighting device (30) is electrically connectable in parallel to the charge storage device via an additional current path (33, 52), wherein the charge storage device is adapted be switched in series with the tapped linear driver and be charged within a second time duration (t4 to t5), when the input voltage (V10) is above a threshold, and discharge when the input voltage (V10) is below a certain level, to provide electrical power to the first lighting device or the second lighting device for powering the first lighting device or the second lighting device.
摘要:
Determining an amount of light output from a solid state lighting (SSL) unit based on a dimmer setting includes determining the dimmer setting of the dimmer during a readout mode by analyzing a power signal received from the dimmer, the dimmer setting indicating a desired level of light, determining power needed at input terminals of the SSL unit for an SSL load to output the desired level of output light, and determining a value of an adjusting signal for adjusting the power at the input terminals of the SSL unit during a power reception mode, based at least in part on the determined dimmer setting, causing the SSL unit to output the desired level of light.
摘要:
The invention relates to powering one or more devices, in particular in the context of Power-over-Ethernet (PoE). In an embodiment of the invention, it is proposed to equip each node (11) with a PD interface (22) that can signal multiples of the standard defined unity load (25 kΩ with tolerances) during the detection process and increase the load during a sequence of detection attempts. In that way, several nodes (11) can share one PSE outlet and determine the number of neighboring loads (11). At the same time, each node (11) will offer full functionality during “normal” stand-alone wiring. This powering concept can be combined with full or limited data communication capabilities.
摘要:
The invention relates to powering one or more devices, in particular in the context of Power-over-Ethernet (PoE). In an embodiment of the invention, it is proposed to equip each node (11) with a PD interface (22) that can signal multiples of the standard defined unity load (25 kΩ with tolerances) during the detection process and increase the load during a sequence of detection attempts. In that way, several nodes (11) can share one PSE outlet and determine the number of neighboring loads (11). At the same time, each node (11) will offer full functionality during “normal” stand-alone wiring. This powering concept can be combined with full or limited data communication capabilities.
摘要:
A circuit and a method of operating LED lighting elements are described. The circuit comprises a first and a second LED lighting element (20, 30). In order to provide a circuit and operating method with reduced complexity, a control circuit (50) controls operation of the first LED lighting element in dependence on a light feedback signal L from a light sensitive element (52). The signal L is dependent on light emitted from the second LED lighting element (30). Said first and said second LED lighting element (20, 30) are in series connection and said control circuit (50) is in parallel connection with said first LED lighting element (20); or said first and said second LED lighting element (20, 30) are in parallel connection and said control circuit (50) is in series connection with said first LED lighting element (20).