Abstract: A fiber optical luminescence measuring system for measuring a change in a physical quantity employs a transmitter/receiver unit and a sensor unit for the physical quantity optically linked by at least one optical fiber. The sensor unit is arranged to emit luminescent light with at least two different decay time constants, where the quotient between the intensities of emitted luminescent light having the different decay times corresponds to a measure of the quantity to be measured.

Abstract: A fiber optical measuring apparatus suitable for measuring physical quantities such as position, speed, acceleration, force, pressure, elongation, temperature, etc., comprises at least one optical fiber for conducting incident light between an electronic unit and a sensor, the sensor comprising at least one luminescent element. The measuring apparatus is characterized in that the physical quantity to be measured is arranged to influence the position of an optical spectral filter, for example of absorption or interference type, relative to the optical fiber in the sensor and/or relative to said luminescent element, and that said spectral filter is arranged to be situated, to a greater or lesser extent, between the end surface of the optical fiber and at least one of the luminescent elements.

Abstract: A fault point in a line section of a three-phase power transmission line, is determined by measuring currents and voltages at a measuring point arranged adjacent the near end of the section. The type of fault (single-phase/multi-phase ground fault/phase-to-phase fault) is determined and the parameters in a quadratic equation are determined using the relative distance (n) from the measuring point to the fault point as a variable. The equation is derived in advance from the electrical relationships between the complex values of the line impedance, the source impedances of the networks located ahead of and behind the fault, and measured currents and voltages following elimination of the fault resistance and possible zero sequence components. The parameters in the equation are determined by the type of the fault, by the measured voltages and currents and by said impedances. The equation is solved directly by means of a numerical square root method.

Abstract: The invention relates to a device for processing optical information of light intensity and/or light polarization and/or phase position and/or spectral composition varying in one, two or three dimensions and possibly varying in time. The processing of the information is adapted to be carried out by electro-optical modulators, for example liquid crystals, and photo-detectors, for example photo-conductors, are electrically connected together with other components, such as resistors and optical filters, so as to obtain circuits with electro-optical feedback. The invention is characterized in that said circuits with electro-optical feedback are arranged to sense the absolute light intensity, etc., at spatially different points of the optical information.

Abstract: A channel-type induction furnace of the teapot type comprising a crucible having a bottom, a channel-type inductor in the bottom and having a partially semi-circular channel opening into said bottom, and straight inlet and outlet melt conduits respectively extending to and from the bottom and positioned substantially tangentially with respect to said channel so as to extend straight into and from the channel.

Abstract: A hollow sound damping plate is arranged between a transformer core and an internal limiting surface of a transformer tank filled with insulating fluid. At least one compressive-force transmitting spring member (8) is arranged between the front wall (6) and the rear wall (5).

Abstract: A method of and a magazine for serving machines for mechanical treatment with a robot. Articles to be machined are supplied on pallets on a first conveyor. A robot collects an article from a pallet on said conveyor, places it in the machine and collects a machined article and places it on a pallet on a second conveyor belt. The robot is connected to or grips an empty pallet and moves this from the first to the second conveyor belt.

Abstract: An industrial robot has a control system with a program memory. During programming, the robot is manually controlled to a sequence of desired positions. At each position, an operating member may be activated to store into the program memory an instruction containing both information about the robot position and information about robot operation at that position.Suitably information about robot operation is entered in the form of identification of a sub-program containing a set or sequence of control signals which have been stored in advance. The sub-program is suitably identified by a number fetched from a buffer memory. For each of the instructions, during the execution of the main program, on the one hand the positioning of the robot is executed and, on the other hand, the sub-program is called and executed.

Abstract: A conductor, provided with insulation for forming windings for transformers and other inductive apparatus comprises two substantially rectangular uninsulated conductor strands, which are arranged with a flat side of one conductor strand facing a flat side of the other conductor strand and with an insulating layer arranged between the flat conductor sides, of a material which forms a glued joint between the conductor strands and which contains a spacer of insulating material to ensure that the conductor strands are held at a distance from each other. The glued joint may be provided either before or after the forming of the conductor into a winding. After the glued joint has been achieved, a winding manufactured from the conductor has a high breaking strength and low additional losses. The conductor is suitable for the manufacture of complicated windings as well, such as interleaved disc windings.

Abstract: A DC arc furnace has a side wall and an electrically conductive hearth, a roof on top of the side wall and over the hearth, an arcing electrode depending through the roof, a plurality of electrical hearth connections extending from the hearth, a first DC power conductor connecting with the hearth connections to provide current and therefore magnetic field symmetry preventing arc deviations, the first and second conductors are extended from a position horizontally offset from the furnace to a point below the hearth and aligned vertically with the electrode, the first conductor forming at least two branches which extend from the point horizontally in opposite directions to beyond the side wall and upwardly so as to jointly connect with the arcing electrode, the second conductor forming at least two branches which extend horizontally from the point in opposite directions with one branch connecting with one of the hearth connections and the other branch connecting with the other one of the hearth connections.

Abstract: A current-limiting electric switch for low-voltage has a contact device with a contact finger and an elongated fixed contact arranged side by side. The contact finger is rotatably arranged and forms at one end a break together with the fixed contact and is at the other end provided with a flexible current connection conductor. The contact finger has its bearing point located between the two ends of a movable arm. Through the influence of electrodynamic forces from short-circuit currents, the contact finger is first rotated in one direction of rotation while maintaining the galvanic contact at the break, whereby the movable arm is displaced so that the distance between the bearing point of the contact finger and the fixed contact is increased. A stop means limits the movement of the contact finger in the first direction of rotation and brings about a continuation of the rotational movement in the opposite direction of rotation resulting in an instantaneous contact opening.

Abstract: A surge arrester includes an elongated insulating housing comprising one or more stacks of electrically series-connected metal oxide varistor blocks arranged between a top terminal and a bottom terminal. To achieve a more even voltage distribution in the longitudinal direction of the surge arrester, the surge arrester comprises larger varistor blocks at the top terminal than at the bottom terminal.

Abstract: The invention is directed to an optical fiber device for measuring of current and/or voltage, including at least one light conductor for transmitting optical signals between an optical transducer and light generating and light processing circuitry, respectively. A sensed electrical measuring signal is transmitted to a transducer for conversion to a mechanical movement which modulates the light flux received by the transducer.

Abstract: A two-pole overcurrent protection device arranged to interrupt the current flowing in a conductor if the current exceeds a predetermined level employs a semiconductor wafer on which is formed a turn-off thyristor and a MOS transistor. The control electrode of the transistor is supplied with a voltage dependent on the on-state voltage drop of the thyristor and, therefore, on its current, and at a certain thyristor current the transistor short-circuits one of the emitter junctions of the thyristor to extinguish the thyristor. For firing the thyristor, one of the base layers thereof is supplied with a gate trigger current via a JFET transistor portion formed in the semiconductor wafer with a horizontal channel region. This transistor portion is designed so that its saturation current exceeds, with a suitable margin, the current necessary for firing the thyristor.

Abstract: A magnetoelastic force transducer with temperature-compensated sensitivity is produced by equally exciting a measuring transducer and a reference transducer having cores of the same material and the same design and in good thermal contact. A spring loads the core of the reference transducer with a constant force. The output signal of the reference transducer is rectified in a phase-sensitive rectifier, the output signal of which is compared with a constant reference voltage. The difference signal resulting from this comparison controls the phase position of the control voltage of the rectifier in such a way that the output signal of the rectifier is brought into agreement with the reference voltage. The output signal of the measuring transducer is also rectified in a phase-sensitive rectifier, which is controlled by said control voltage and the output signal of which constitutes the temperature-compensated measured signal.

Abstract: A system for stirring in continuous casting is formed by an inductive stirrer which inductively stirs molten metal in a continuously cast strand and at least one set of two water-cooling pipes positioned in front of the stirrer and having nozzles which eject water cooling-sprays against the strand. The two pipes have ends extending beyond the field and between their ends are electrically isolated from each other and the stirrer. By electrically interconnecting these ends outside of the field, the two pipes form a closed electric loop in which currents induced by the stirrers field cancel so that the net current flow is zero and the stirrer's field is not shielded from the strand.

Abstract: A DC arc furnace has an electrically conductive hearth adapted to contain a melt, and at least one arcing electrode above the hearth and adapted to form a heating arc with the melt when the hearth and electrode are supplied with DC power. The hearth has a wear lining directly contacted by the melt through which electrical conductors extend from the bottom of the wear lining to its top. Layers of electrically conductive bricks are under the wear lining and have a top layer electrically connecting with the electrical conductors, and a melt plate under the layers of the electrically conductive bricks is connected to DC power. The layers of conductive bricks have a bottom layer in electrical connection with the melt plate. The improvement comprises a layer of mixed bricks between the top and bottom layers of the electrically conductive bricks and formed by alternating electrically conductive and non-conductive bricks.

Abstract: A sensor element adaptable for measurement of a physical parameter formed of a crystalline material and emitting luminescent spectra upon excitation by light spectra and the influence of said physical parameter. A first layer emitting luminescent spectra is formed of a semiconductor material containing dopant providing shallow energy levels and recombination centers with a concentration between 10.sup.15 to 10.sup.18 cm.sup.-3, and sandwiched between second and third layers of semiconductor material having low absorption for light excitation of the first layer, and the respective lattice constants of the second and third layers being substantially coincidental with the lattice constant of the first layer. The sensor element is formed of GaAs for the substrate and AlGaAs for the semiconductor layers, with appropriate variation in the concentration Al, Ga, and As for the various layers.

Abstract: An hermetic seal at a smooth interface between a gallium arsenide body and a glass body is effected without organic or inorganic binders by thermally bonding the bodies at the interface while ensuring that the oxygen concentration at the interface is so low that there is no optically detectable variations in color of the gallium arsenide close to the interface.

Abstract: A device for measuring the rolled-up length of web forming a roll when a web break has occurred during formation of the roll employs a web break indicator to indicate a web break. Normal web length measuring is carried out by counting pulses from a pulse transducer driven by a roller turned by the moving web and this is stopped on web break. A calculation of the circumference of the web roll on the occasion of the web break is made with the further aid of a pulse transducer on the shaft of the web roll and a counter and logic unit. Too loosely wound web material is removed from the roll and the circumference of the roller decreases. After joining the web and renewed winding, a calculation of the roll circumference is continuously performed by means of the pulse transducers. When the circumference of the roll resumes the size it had at the moment the web break occurred, normal length measuring is automatically resumed.