Abstract: The present disclosure is directed to a direct-light generator for sun-sky-imitating illumination devices configured for generating natural light similar to that from the sun and the sky The generator includes a first emitting surface and an array of light-emitting devices configured to generate from a primary light a direct light which exits the first emitting surface along a direct-light direction. The direct light exiting the first emitting surface has a luminance profile which has a narrow peak in the angular distribution around the direct-light direction and is uniform across the first emitting surface. Each light-emitting device includes a light emitter having an emitting surface and at least a pair of collimation lenses illuminated by the light emitter.

Abstract: The aim of the invention is to detect an arc in an assembly for transmitting a direct voltage. This aim is achieved by a communication transformer having a primary winding and a secondary winding, the secondary winding being connected to a transmitting device, which is designed to impress a communication signal onto the secondary winding of the communication transformer, and the primary winding being connected to one of the direct voltage lines in order to feed a communication signal transformed by the communication transformer to one of the direct voltage lines. In order to detect, in the assembly, the arc signal caused by an arc, the secondary winding is connected to an arc detection unit, which is designed to detect an arc signal transformed by the communication transformer.

Abstract: The aim of the invention is to detect an arc in an assembly for transmitting a direct voltage. This aim is achieved by a communication transformer having a primary winding and a secondary winding, the secondary winding being connected to a transmitting device, which is designed to impress a communication signal onto the secondary winding of the communication transformer, and the primary winding being connected to one of the direct voltage lines in order to feed a communication signal transformed by the communication transformer to one of the direct voltage lines. In order to detect, in the assembly, the arc signal caused by an arc, the secondary winding is connected to an arc detection unit, which is designed to detect an arc signal transformed by the communication transformer.

Abstract: To recognize a fault in an arrangement including a transformer having a primary winding connected in series with a DC voltage line and a secondary winding coupled magnetically to the primary winding, and including an evaluation unit that processes a secondary signal on the secondary winding, a signal component at at least one frequency is determined from the secondary signal and a signal level of the signal component is compared with a signal threshold. The fault is detected when the signal level falls below the signal threshold.

Abstract: The aim of the invention is to detect an arc in an assembly for transmitting a direct voltage. This aim is achieved by a communication transformer having a primary winding and a secondary winding, the secondary winding being connected to a transmitting device, which is designed to impress a communication signal onto the secondary winding of the communication transformer, and the primary winding being connected to one of the direct voltage lines in order to feed a communication signal transformed by the communication transformer to one of the direct voltage lines. In order to detect, in the assembly, the arc signal caused by an arc, the secondary winding is connected to an arc detection unit, which is designed to detect an arc signal transformed by the communication transformer.

Abstract: The present disclosure is directed to a direct-light generator (10) for sun-sky-imitating illumination devices (100) configured for generating natural light similar to that from the sun and the sky, comprising a first emitting surface (22) and an array of light-emitting devices (21) configured to generate from a primary light a direct light (13) which exits the first emitting surface (22) along a direct light direction (15), wherein the direct light (13) exiting the first emitting surface (22) has a luminance profile (Ldirect(x, y, ?, ?)) which has a narrow peak (14) in the angular distribution around the direct-light direction (15) and is uniform across the first emitting surface (22), wherein each light-emitting device (21) comprises a light emitter (24) having an emitting surface and at least a pair of collimation lenses (25,27) illuminated by the light emitter (24), each pair of collimation lenses (25,27) comprising a pre-collimation lens (27) comprising a light inlet surface (27a) facing the light emitte

Abstract: An optical device for imaging a first, object-side set of mutually parallel bundles of beams onto an image surface, includes an optical beam expansion unit; an optical rearrangement unit configured to rearrange the first set of mutually parallel bundles of beams while maintaining mutually parallelism to obtain a second set of mutually parallel bundles of beams; an optical element configured to direct the second set of one or more bundles of beams onto the optical beam expansion unit by means of bundling, so that the optical beam expansion unit is reached by a third set of bundles of beams, the optical beam expansion unit being configured to expand each bundle of beams of the third set to obtain a fourth set of expanded bundles of beams; and an optical imaging unit configured to image the fourth set of expanded bundles of beams onto the image surface.

Abstract: To recognize a fault in an arrangement including a transformer having a primary winding connected in series with a DC voltage line and a secondary winding coupled magnetically to the primary winding, and including an evaluation unit that processes a secondary signal on the secondary winding, a signal component at at least one frequency is determined from the secondary signal and a signal level of the signal component is compared with a signal threshold. The fault is detected when the signal level falls below the signal threshold.

Abstract: The aim of the invention is to detect an arc in an assembly for transmitting a direct voltage. This aim is achieved by a communication transformer having a primary winding and a secondary winding, the secondary winding being connected to a transmitting device, which is designed to impress a communication signal onto the secondary winding of the communication transformer, and the primary winding being connected to one of the direct voltage lines in order to feed a communication signal transformed by the communication transformer to one of the direct voltage lines. In order to detect, in the assembly, the arc signal caused by an arc, the secondary winding is connected to an arc detection unit, which is designed to detect an arc signal transformed by the communication transformer.

Abstract: A method of testing the position of an edit point between an edited magne tape packed in a cassette and a leader spliced ahead of the recording or a trailer spliced after the recording, includes determination of a distance of the edit point from a cue tone situated, for example, at least before the beginning of the recording, or from the end of the recording and generating first and second output signals commensurate with an optical measurement of the edit point and an inductive measurement of the recorded cue tone. In dependence of the position of the recorded cue tone behind the leader or ahead of the trailer as viewed in tape travel direction, a time difference, such as, between the ascending flank of the second output signal and the descending flank of the first output signal, is determined. The determined time difference is then compared with upper and lower limits which define a tolerance range for the position of the edit point before or behind the recorded cue tone.

Abstract: Light conductive fibers being embedded as crack monitors in reinforced compound material are protected as follows. During laminate assembly the fiber ends are slipped into relatively short teflon hoses but being provided to be at least in parts embedded in the compound parts to be made; the ends of the hoses that will be embedded are closed with a cold curing laminate resin; the fiber ends with enclosing teflon hoses will be threaded through laminate openings during assembly of the lamination, and the fiber ends with projecting hoses are also inserted in a conical bore of an assembly device; open areas and portions of the compound part adjacent to the conical bore of the assembly tool are filled with laminate resins; a protective cover is then placed onto said bore and over the teflon hose protected fiber ends prior to curing of the part; and the thus prepared part is cured in an autoclave.

Abstract: A system for sensing fractures in a structural component that has a plurality of light conductor fibers attached to or incorporated in the structural component, such as an aircraft body or wings made of fiber reinforced material. The light conductor fibers function as fracture sensors. For this purpose the light supply to each individual fracture sensing light conductor and the interrogation whether a light signal has passed through the light conductors is controlled by a computer. The absence of a light signal at a particular conductor signifies a fracture and this fact may be indicated on a display in the cockpit of an aircraft.

Abstract: An arrangement for detecting cracks within a construction or structure part made of multiple lamina in a compound fashion and wherein at least some of said lamina are made of fibres, being at least partially embedded in synthetic resin, includes light conducting fibres in said lamina taking the place of regular ones of said fibres within a pattern of such fibres either as part of the weaving pattern or as particular interposed layer.

Abstract: The invention relates to a measuring device for determining cracks. Light conductive fibers or film are provided as crack detectors in this measuring device which fibers or films are applied directly upon the construction parts. Light is coupled into these light conductive fibers by means of a coupler and the passage of light is monitored at the free end. A fiber fracture serves as irreversible crack indication.

Abstract: Laminated parts of structural material receive as embedment light transmitting fibers, preferably in addition to reinforcing fibers, and light transmission through the light transmitting fibers is monitored for purposes of determining pattern irregularities and formation of cracks.

Abstract: A centrifuge for biological specimens is constructed to include one or two additional concentric rotors being independently drivable and provided with means for transfer of objects to and/or from the main centrifuge. The rotating specimen is under observation from a stationary observation point.