Abstract:
The present invention is based on a regulation circuit (200a, 200b) for making available a constant current supply on the basis of a transformer principle, in which there flows through the luminescent diodes (D1, . . . ,DN) a triangular a.c. current (ID) varying periodically around a d.c. current value. With this method it is afforded by means of a circuitry provision that both the charging and also the discharging current (IL1) of an inductive reactance (XL1) connected in series to the luminescent diodes (D1, . . . ,DN), functioning as a storage choke (L1) for filtering of mains harmonics, flows as diode current (ID) through the luminescent diodes (D1, . . . ,DN). The advantage of this method consists in a significant reduction of the overall power loss (PV,ges) of the LED illumination module (100). According to one exemplary embodiment of the invention the ceramic circuit board (102) of the LED illumination module (100) in accordance with the invention has a direct mains current supply (104, 108), which for protection from mechanical damage is accommodated in a transparent housing (106) having a highly transparent polymer mass (110) serving as optically active lens surface.
Abstract:
An Internet or intranet based document retrieval system contains a database that relates document word-pair patterns to topics. In response to a word submitted by a requestor, the system retrieves documents containing that word, analyzes the documents to determine their word-pair patterns, matches the document patterns to database patterns that are related to topics, and thereby assigns topics to each document. If the retrieved documents are assigned to more than one topic, a list of the document topics is presented to the requestor, and the requestor designates the relevant topics. The requestor is then granted access only to documents assigned to relevant topics. A knowledge base linking search terms to documents and documents to topics is established and maintained to speed future searches.
Abstract:
The invention concerns a 3D milling machine and a 3D milling process. The milling machine comprises a milling unit (2) with a motor driven work spindle (4) for receiving a milling tool, a work table for clamping work pieces, guide and drive device for producing relative movement of the milling unit and the work table in at least three spatial directions, and a laser device (12) for emitting a laser beam. A laser assisted milling of free-form surfaces is made possible in that the milling unit is a spherical cutter (6), further, that a mounting device (30, 32) and a driving device (36, 38) are provided for producing a precise movement of the laser emitter (12) about a point on the beam axis, such that the laser beam (14) circles about a central axis, which intersects the axis of the work spindle (4) at an acute angle, as well as a mounting device and a driving device for at least one of pivoting and rotating of the work table (18) about at least one axis.
Abstract:
The invention relates to a tool for applying punched rivets, either full rivets or semi-tubular rivets. The tool having a blank holder for pretensioning assembly pieces, especially metal sheets; a rivet punch movable in an axial direction within a cylinder of the blank holder; and a die that is arranged opposite the blank holder and punch and provided with an annular prominence on an end face thereof and facing the rivet punch. A radial outside section of said end face concentrically surrounds said annular prominence, the outside section of said end face being displaceable relative to the annular prominence as a function of one of the penetration depth of the rivet into the assembly pieces and the force that the rivet punch exerts on the rivet.
Abstract:
The invention relates to modular elements (1) of differential construction which are particularly suitable for constructing cold-joined large bodywork or containers. All the components of the modular elements, substantially shell (2), shaping frames (3), edge profile (5) and optionally stringers (4) extending transversely to the frames and acting as buckling resistors, are cold-joined to each other, e.g. by pressure joining, punch riveting and the like. As a result, firstly rapid production with good surface quality is achieved, and secondly different materials such as iron and non-ferrous metals, fiber reinforced plastics etc. can be freely combined in hybrid structures to construct the modular elements, the local arrangement of materials in the modular element having to be adapted to the desired mechanical properties. The structure described herein contributes substantially to mechanized, highgrade software-supported manufacture in which the geometrical data for the half-finished products of the modular elements can flow directly (on-line) from a CAD construction, thus achieving at the same time currently unobtainable flexibility when producing different external shape variants even for a low level of mass production.
Abstract:
The invention relates to a device for purifying protein-containing solutions such as blood, blood plasma or cell culture media, where a biocompatible support material made of a plastic material, selected from the group of polyacrylates, polymethacrylates, polysulfone and polyether sulfone, is coated with albumin, which is bound by peptide binding. In addition, the invention relates to a method of producing the support material according to this invention and the use of the device.
Abstract:
The invention concerns a multilayer polymer film and a multichamber bag, whose bag chambers are formed by seams in the outer border zone and by at least one seam in the chamber separation zone, whereby the seams are formed from the polymer materials facing the chambers. The polymer materials facing the chambers are inseparably sealed together in the outer border zone and sealed together in the chamber separation zone such that the seam is separable with a force which lies in the range from 5 to 20 N. The different strength of the bond from the sealing process is obtained by varying sealing temperatures.
Abstract:
The invention concerns a cannula comprising a cannula tube with a preferably rigid upper section, an end section which is bent laterally and a hook-shaped curved section which has in its concave side a tangentially inward ground lumen opening. The lumen opening has a sharply inwardly directed rear edge. This results in the advantage that during piercing of natural and synthetic walls the cutting of plugs from the material to be perforated is avoided.
Abstract:
The invention relates to an LED operating circuit in which a second module (2), preferably a light management module, with an additional sub-module (C), preferably a constant flow source, supplies an LED module (F) which has one or more LED sections (8). A control unit (E) of the second module (2) is embodied such that it can access a memory (4) of the second module (2) in order to read an identification of the LED-module (F) or to read the contents stored in the memory (4).
Abstract:
The invention relates to an LED driver circuit comprising: a circuit block for providing an adjustable DC voltage and a clocked constant current source, e.g. a DC/DC converter that is supplied with the DC voltage, comprising a switch that is clocked by a control circuit in such a way that a reduction of the activation period ton of the switch leads to a reduction in the provision of power. One or more LEDs can be supplied from the constant current source and in addition to reducing the activation period t0N, the control unit is designed to change at least one other control variable of the constant current source or the circuit block in order to provide the direct current.