摘要:
The invention relates to a nuclear magnetic resonance imaging radio frequency-receiver (112; 216; 308; 404), the receiver (112; 216; 308; 404) being adapted to receive analog signals from at least one radio frequency receiver coil unit (106; 200; 202; 300; 400; 402), the radio frequency receiver (112; 216; 308; 404) comprising: an analog-digital converter (118; 226) to convert the analog pre-amplified magnetic resonance signal into a digital signal, means (120; 230) for digital down converting the digital signal and a first communication interface (130; 252) adapted for transmitting the down converted digital signal via a communication link (e.g. wireless, optical or wire-bound).
摘要:
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.
摘要:
A light generating device (1) is provided with at least a voltage input (21) adapted for receiving a variable voltage, at least three LED circuits (10), coupled with said voltage input (21), wherein each LED circuit (10) comprises a LED unit (14) and controllable current regulator (15) to control the current through said LED circuit (10). The light generating device (1) further comprises a controllable switch matrix (30) comprising a plurality of switches (25, 26, 27), said switch matrix (30) is configured to operate in at least three different switching modes and a controller (50), connected at least with said switch matrix (30), configured to determine said variable operating voltage and to control the switching mode of said switch matrix (30) in dependence of the determined operating voltage. To provide an efficient operation of such device (1) with a variable operating voltage, such as an AC voltage, in a first switching mode, said LED units (10) are connected parallel to each other, in a second switching mode, at least two of said LED units (10) are connected in series and in a third switching mode, said LED units 10 are connected in series with each other.
摘要:
A transducer device for detecting an environmental state within a biological material including a channel comprising a fluid, a hydrogel material, which is adapted to change its volume when getting into contact with an environmental material and/or when detecting an environmental change, and which is mechanically coupled to the channel such that the volume of the channel changes when the volume of the hydrogel material changes. The transducer device further includes a sensor, which is adapted to generate a signal upon detection of the change of a physical property of the fluid that is induced by the volume change of the channel. By applying the transducer device, an accurate monitoring of physiological parameters, for which the hydrogel material is sensitive is possible. It is also possible to apply the transducer device outside of the bodily lumen, for example to monitor the blood of a patient outside the bodily lumen.
摘要:
In a method of lighting at least part of a space, a light emitting diode (LED) string is used. The LED string comprises a first LED segment and at least one further LED segment, which are connected in series, each LED segment comprising at least one LED. The LED string is powered by a rectified AC voltage. The first LED segment is powered when the rectified AC voltage is above a first voltage level, and the first LED segment and the further LED segment are powered when the rectified AC voltage is above a second voltage level higher than the first voltage level. The first LED segment is arranged to radiate light to a first volume of the space, and the further LED segment is arranged to radiate light to a second volume of the space, the first volume being at least partly different from the second volume. The first volume may at least partly overlap the second volume.
摘要:
Disclosed are systems and methods for providing multi-channel illumination. A reflector and at least four solid state light sources are operable to emit light. A plurality of combinations of the solid state light sources are identified, where each of the combinations is operable to emit light that matches a target color point. The combinations are ranked based on their respective luminous flux value, and at least one of the combinations is selected based on the rank. A duty cycle of a control signal of each light source of the selected combinations is determined to control light emitted from the reflector.
摘要:
The invention relates to a method and a device for driving an LED string of a first LED segment (11) and at least one further LED segment (12, 13, 14) connected in series. Each LED segment has at least one light emitting diode, LED. The LED string is powered by a rectified AC mains voltage. The first LED segment (11) is powered when the rectified AC mains voltage is above a first voltage level, and the first LED segment and the further LED segment are powered when the rectified AC mains voltage is above a second voltage level higher than the first voltage level. The first LED segment emits light having a first color temperature, and the further LED segment emits light having a second color temperature higher than the first color temperature. The light emitted by the first LED segment and the light emitted by the further LED segment are superimposed. The color temperature change of the light emitted by the LED string, when dimmed, resembles the color temperature change of an incandescent lamp.
摘要:
There is provided an arrangement for spot illumination (14). The arrangement provides an improved collimation and color mixing unit comprising a LED array (1), a convex shaped reflector (15a), a field lens (21) and an additional cylindrical reflector (15b) at the exit aperture of the system. In combination with an optical projection system which may comprise at least two additional zoom lenses and a gate (in which several maskers, gobos or shutters could be inserted) the system allows color mixing in an extended operational range including out of focus zoom settings often used to get soft edge spots.
摘要:
A wearable electronic device such as a wrist watch (60) is supplied with conventional clock with two pointers (32,33). The device displays a parameter indicative of how “cool” the wearer has been over the past period as a function of time, using the time axis of one of the pointers (32,33). “Coolness” can be based on the measurement of related physiological parameters like heart-rate, body temperature, movement, skin resistance or muscle activity. “Coolness” of a person is understood as being the ability to cope with stress. Therefore, the stability of physiological parameters can be used to derive a signal for the subjective trait called “coolness”. All physiological parameters can be measured by sensors (10) in the watch (60) or in the strap (50). The invention is used as a gadget for self expression and emotional feedback.
摘要:
A system for detecting at least one contamination species in an interior space of a lithographic apparatus, including: at least one monitoring surface configured to be in contact with the interior space, a thermal controller configured to control the temperature of the monitoring surface to at least one detection temperature, and at least one detector configured to detect condensation of the at least one contamination species onto the monitoring surface.