Abstract: 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).

Abstract: A system comprising a driver circuit wherein the driver circuit comprises a converter. The system further comprises a controller operable to control a ratio between an input voltage supplied to the driver circuit and a target output voltage to be output from the driver circuit by varying a pulse width modulated signal, and by switching between operating modes of said converter. The controller is configured to determine that the driver circuit is operating in an undesired state caused by a combination of the duty cycle and the operating mode of the converter. The system further comprises a resistance adjustment circuit configured to adjust an equivalent output resistance of the driver circuit in response to the controller determining that the driver circuit is operating in an undesired state.

Abstract: A driver circuit for driving an LED arrangement (22), comprising: a power source for providing the LED arrangement with a regulated driving current, said converter (20) being adapted to convert an dimmed input power into said driving current; a current sensing element (42) in series with the LED arrangement (22) and adapted to sense the LED arrangement current through the LED arrangement (22); a bleeder circuit (40) having a bleeding path connected in parallel with the LED arrangement, adapted for removing a bleed portion from the driving current so as to decrease the output power of the LED arrangement; and a control circuit for enabling said bleeder circuit when the LED arrangement current sensed by the current sensing element is below a threshold so as to further dim the LED arrangement down.

Abstract: The invention describes a driver arrangement (1) for driving a semiconductor lighting load (2), which driver arrangement (1) comprises a first power converter (10) arranged to drive a portion (2_10, 2_10_11) of the lighting load (2); a second power converter (11) arranged to drive a portion (2_11, 2_10_11) of the lighting load (2); a monitoring arrangement (12) realized to monitor an operating characteristic (12A, 12B, 12C, IR3O) ° f the second power converter (11); and a control signal generator (13) for generating a control signal (130, Vshunt) for the first power converter (10) on the basis of the monitored operating characteristic (12A, 12B, 12C, IR3O). The invention also describes a lighting arrangement (100), which lighting arrangement (100) comprises a semiconductor lighting load (2); and such a driver arrangement (1) for driving the semiconductor lighting load (2). The invention also describes a method of driving a semiconductor lighting load (2).

Abstract: The invention relates to a LED lighting system comprising a power supply circuit and at least one LED module. The power supply circuit comprises input terminals (K1, K2) for connection to a supply voltage source and output terminals (K3, K4),and a driver circuit (I, II) coupled between the input terminals and the output terminals for generating a LED current out of a supply voltage supplied by the supply voltage source, and comprising a driver control circuit (II) with an input terminal (K7) for receiving a current control signal and for generating a LED current in dependency of the current control signal.

Abstract: A Power-over-Ethernet (PoE) device for use in a PoE system is described. The PoE device comprising a first PoE port for connecting the device to an upstream PoE device or a central control unit, a second PoE port for connecting the device to a downstream device or PoE device and a control unit for controlling data and/or power communication between the first and second PoE port. The control unit further comprises a first power input terminal connected to the first PoE port to receive electrical power for powering the control unit.

Abstract: A system for supplying a load comprising: an input inductor configured to receive an input voltage, a selection module connected to the inductor via a switching node, and a multi-level half-bridge stage comprising a plurality of half-bridge stages, each half-bridge stage comprising a pair of switches connected between a switching node; a power combining stage coupled to each half-bridge stage using parallel bus voltage lines output from the multi-level half-bridge stage, the power combining stage configured to output a voltage to the load; and a controller configured, based on the input voltage, to selectively control a half-bridge stage to operate in a half-bridge mode to provide a stepped-up voltage on a bus voltage line, wherein the controller is further configured to control the power combining stage to provide a voltage between the bus voltage lines and the sum of these voltages is higher than a peak of the input voltage.

Abstract: The invention provides a lighting unit (1) comprising a light source (20) and an actuator (40). The light source (20) is arranged to generate, during use, a light beam (B) whose light intensity is dependent upon an electrical power signal (I; V). The actuator (40) is arranged to orient, during use, the light beam (B) in an orientation dependent upon the electrical power signal (I; V). The orientation of the light beam has a pre-determined relationship to the light intensity of the light beam. The invention further relates to a lighting system (100) comprising at least one lighting unit, a space (1000) comprising such a lighting system, and a use of such a lighting system.

Abstract: 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.

Abstract: 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).

Abstract: 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 k? 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.

Abstract: A Power-over-Ethernet (PoE) device (200) for use in a PoE system is described. The PoE device (200) comprising a first PoE port (210) for connecting the device to an upstream PoE device or a central control unit, a second PoE port (220) for connecting the device to a downstream device or PoE device and a control unit (240) for controlling data (335) and/or power communication (400) between the first (210) and second (220) PoE port. The control unit (240) further comprises a first power input terminal (305) connected to the first PoE port (210) to receive electrical power (320) for powering the control unit (240).

Abstract: The present invention relates to Power-over-Ethernet (PoE) systems. The invention proposes to use a classification event to communicate from the PD (121) to the PSE (110, 910). A sensor (310, 410, 510a, 510b) may determine a sensor value, shut down the PoE connection, and reconnect so that the power up cycle with the PSE (110, 910) will start. The sensor (310, 410, 510a, 510b) provides a PoE resistance related to a class 0, 3 where the class relates to the sensor value (e.g., class 0=presence detected; class 1=no presence detected). This procedure may be repeated (e.g. continuously, every minute or whenever the sensor value changes such that the PSE (110, 910) needs to be informed) and if needed multiple cycles can be used to increase the length of the message communicated.

Abstract: 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).

Abstract: A system for supplying a load comprising: an input inductor configured to receive an input voltage, a selection module connected to the inductor via a switching node, and a multi-level half-bridge stage comprising a plurality of half-bridge stages, each half-bridge stage comprising a pair of switches connected between a switching node; a power combining stage coupled to each half-bridge stage using parallel bus voltage lines output from the multi-level half-bridge stage, the power combining stage configured to output a voltage to the load; and a controller configured, based on the input voltage, to selectively control a half-bridge stage to operate in a half-bridge mode to provide a stepped-up voltage on a bus voltage line, wherein the controller is further configured to control the power combining stage to provide a voltage between the bus voltage lines and the sum of these voltages is higher than a peak of the input voltage.

Abstract: The invention relates to lighting devices (100) for producing ultimate light comprising first light of a relatively warm color and second light of a relatively cool color. The lighting devices (100) comprise first and second circuits (1, 2) for producing the first and second light, third circuits (3) for reaching a temperature per intensity state of the ultimate light, and fourth circuits (4) thermally coupled to the third circuits (3) and comprising temperature-dependent circuits for giving the ultimate light a, for example, relatively warm color at lower intensity states and for giving the ultimate light a, for example, relatively cool color at higher intensity states.

Abstract: The present invention relates to a method and apparatus for controlling data transfer and power supply to at least one load device (61-64) connected to a two-wire data communication cable (70) in a bus-type structure. Power supply and data transfer are multiplexed via the two-wire data communication cable so that a standard coaxial cable can be used for shared power and data transport, enabling the operation of lighting applications or other applications in retail and office, based on cheap, flexible, preconfigured cables in a bus topology and using known chipsets.

Abstract: An appliance unit (3) is for electrical connection in series to a control unit (1) and to a power supply via the control unit (1). The appliance unit (3) comprises an appliance module comprising at least one controllable light generating module (23) and/or at least one controllable auxiliary module (25) for performing functionality other than light generating, and a control module (27) for negotiating a power mode for the appliance unit (3) with the control unit (1). The appliance module is controlled based on the power mode. A bypass module (21) is able to pass current through the appliance unit (3), such that the bypass module (21) is configured to pass a current to enable the control unit (1) to be powered separately from any current passed by the at least one controllable light generating module (23) and the at least one controllable auxiliary module (25).

Abstract: The present invention relates to a powered device (331a, 331b, 531a) with two interfacing connections. The powered device (331a, 331b, 531a) comprises power switching units (350a, 350b, 550a1, 550a2) for forwarding the data signal as well the power received on the input to the output. Forwarding may be based on a detection of the powering state of the PD. In another embodiment, the Power-over-Ethernet input/output ports function bi-directionally, thereby allowing the user to daisy-chain devices in any direction. As power switching units, relays or solid-state power switches may be used.

Abstract: A driver circuit for driving an LED arrangement (22), comprising: a power source for providing the LED arrangement with a regulated driving current, said converter (20) being adapted to convert an dimmed input power into said driving current; a current sensing element (42) in series with the LED arrangement (22) and adapted to sense the LED arrangement current through the LED arrangement (22); a bleeder circuit (40) having a bleeding path connected in parallel with the LED arrangement, adapted for removing a bleed portion from the driving current so as to decrease the output power of the LED arrangement; and a control circuit for enabling said bleeder circuit when the LED arrangement current sensed by the current sensing element is below a threshold so as to further dim the LED arrangement down.