Abstract:
A LED light source comprises -a full bridge rectifier equipped with a first input terminal and a second input terminal for coupling to output terminals of the phase cut dimmer, -a series arrangement comprising N LED loads, a first and second end of said series arrangement being coupled to a first output terminal and a second output terminal of the full bridge rectifier respectively, -control means for during a period of the rectified AC supply voltage subsequently making the LED loads comprised in the first series arrangement carry a current, one by one and in dependency of the momentary amplitude of the rectified AC supply voltage when the momentary amplitude increases and for subsequently making the LED loads stop carrying a current, one by one, and in dependency of the momentary amplitude of the rectified AC supply voltage when the momentary amplitude decreases, said control means controlling the current through the LED loads at zero when the output voltage of the phase cut dimmer equals zero and controlling the current through the LED loads at a value that is independent from the phase angle of the phase cut dimmer when the output voltage of the phase cut dimmer differs from zero Volt. In order to make the LED light source compatible with a phase cut dimmer, the LED light source is further equipped with -a switchable bleeder current source coupled between the first and second output terminal of the full bridge rectifier, -a latch coupled between the first and second output terminals of the full rectifier bridge and comprising a series arrangement of a resistor and a capacitor to prevent the current through the dimmer from crossing zero after a leading edge generated by the phase cut dimmer, in case the phase cut dimmer is a leading edge phase cut dimmer, -a unidirectional element arranged in series with the capacitor for preventing discharging of the capacitor via the LED loads or the adjustable bleeder current source, and -a clamp circuit coupled to the capacitor and comprising a current source for discharging the capacitor and providing a low ohmic path for the dimmer current when the dimmer is off.
Abstract:
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 (V s ), load terminals (20) for providing a drive voltage (V L ) and/or a drive current (I L ) 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.
Abstract:
A method and a controller for controlling properties of light emitted from a light-emitting device comprising a plurality of light sources, each of the light sources being configured to emit light within a predetermined wavelength range, are disclosed. The intensities of the plurality of light sources included in the light-emitting device are adjusted by means of two independent steps. In a first step, a color point of the available color points of light emitted from the light-emitting device is selected. In a second step, one or more settings for the intensities of the plurality of light sources relatively to each other are selected. The one or more settings are selected from settings, each of which settings, when applied to the plurality of light sources, results in that the light emitted from the light-emitting device exhibits the color point selected in the first step.
Abstract:
A lighting device comprising a plurality of light emitting elements (1), and a beam shaping optics (7) having an entrance aperture (6). Each light emitting element is optically connected to a set of optical fibers (5) each having a first end optically connected to the light emitting element and a second end optically connected to the entrance aperture (6), so as to guide collimated light from the light emitting element to the beam shaping optics (7). The light emitting elements are distributed over an area larger than the entrance aperture (6).
Abstract:
The invention relates to a lamp and a method, preferably adapted for generating high power in laser applications. The lamp (1) comprises a source (3) adapted for emitting optical radiation along an optical path and a holder (5) comprising a fluorescent body (4), wherein the holder (5) is arranged in the optical path, a collecting unit (8) is provided which is adapted for transmitting at least a portion of optical radiation emitted by the fluorescent body (4) to an output of the lamp (1), and the fluorescent body (4) comprises a shape being elongated in a predetermined direction. In this way, a small spot and little divergence is provided in conjunction with good heat dissipation leading to a high optical performance.
Abstract:
The present invention provides for the coaxial encapsulation of a plurality of cells in a single elongated compartment. By this encapsulation, the cells are protected by at least one layer of separation material and kept in close contact, which leads to a better vitality of the encapsulated cells and consequently results in higher chances to form microtissue. Methods and devices for the production of such encapsulated cell compartments are disclosed as well as medical uses of such compartments in cell, tissue therapy and tissue engineering.
Abstract:
The present invention provides a microfluidic device comprising at least one fluidic channel (3) and an integrated ultrasound transducer, said transducer comprising a first vibratable membrane (5) being at least partially in contact with fluids within the fluid channel and a cavity (6) adjacent the membrane (5), said membrane being adapted to transfer fluid from the fluidic channel into the cavity and vice versa.
Abstract:
The present invention relates to a method for illuminating a scene having an average lighting setting, the method comprising the steps of receive scene information from an image sensor (110) comprising a plurality of pixels, determine chromaticity coordinates for the scene based on the scene information, and determine, based on the chromaticity coordinates, control values used for driving the at least two differently colored light sources (L 1 , L 2 , L 3 ), thereby allowing for illumination of the scene without essentially changing the average lighting setting of the scene. The present invention provides for the possibility to in a more precise way match the average lighting setting of the scene, wherein it is possible to produced light that assure a more natural rendering of illuminated objects in the scene. In comparison to the prior art, for light sources which have spectra far from the black body curve, the chromaticity coordinates are a better representation of the color of ambient light illuminating the scene than when using the correlated color temperature. The present invention also relates to a corresponding illumination device (100).
Abstract:
The invention provides a porous biological assay substrate suitable for detecting at least one analyte in at least one sample fluid. The substrate is provided with capture probes in plural spot areas, the capture probes being able to each specifically bind at least one target analyte. The substrate comprises a top layer provided with a plurality of holes in a pattern that matches the spot areas. The substrate thereby shows improved binding efficiency. The invention also relates to a method and device for producing the biological assay substrate, and to a method for examining analyte fluids using the substrate.