Abstract: For multiple strand casting in the horizontal, a distributor vessel and several molds connected thereto, are arranged on a carriage being movable in direction of multiple parallel casting lines, and a plurality of stationary mounts are provided to be connected to bar-like lateral extensions of the molds by means of hydraulically operated plungers.

Abstract: A method for continuous casting of steel in a horizontal casting mode and using a cycle being comprised of an extraction stroke, a holding period, a retraction stroke and another holding period, the retraction speed, the retraction length and the holding period between an extraction stroke and a retraction stroke are maintained constant; and extraction speed and extraction length as well as the holding period between a retraction stroke and the next following extraction stroke are varied for adaptive purposes.

Abstract: Apparatus for controlling the oscillations of a mold for continuous casting of metal, the mold being mounted on a table which is connected, in turn, to three spaced apart drives and three load relief springs; three displacement path transducers track each of the drives; a source of reference signals provides reference signals representing the desired oscillation, as to contour, amplitude and rate; actual and reference signals are compared by and in stages which provide correction signals for the drives.

Abstract: A method of horizontal continuous casting of thin and wide ingots. The method includes providing a withdrawal or extraction length of 50 to 300 mm at a speed in excess of 3 meters per second up to 20 meters per second and holding the ingot for 1 to 5 seconds. Further, the ingot can be retracted to correspond to the length reduction due to cooling. The effect of the invention is an improvement in ingot quality.

Abstract: An electrode assembly for a furnace having a refractory lining. The electrode assembly has a conductive casing which houses a replacement body. The casing is sheathed by a conical refractory component with the broad end of the component disposed at the exterior of the furnace and the narrow end adjacent the head of the electrode. The replacement body of the electrode has a central bore, a chamber at the head of the electrode, an annular slit defined between the replacement body, and an outlet through which a cooling fluid is circulated by a suction pump connected to the electrode through the outlet. The electrode head is arranged in the refractory lining of the furnace to provide a space for the deposit of solidified molten melt which forms a protective layer over the electrode head.

Abstract: A device for conveying and stacking sheets of paper has a first conveying unit receptive of sheets for stacking and a second conveying unit downstream of the first conveying unit for removing a stack and wherein the units include upper and lower belts. A single upper belt is associated with two lower belts for the two units and the upper belt is alternately coupled for movement with one or the other of the two lower belts at the same speed as the lower belt to which it is coupled to effect either the stacking of the sheets or the movement of the stack.

Abstract: In the changing of the dimensions of sheets of paper to be stacked by a paper stacking apparatus including a conveying station, adjustable upper tapes moving about reflection rollers, separating shoes, ejector rolls, separating plates and stopper boards, the improvement which comprises displacing the upper tapes along with their deflection rollers, the separating shoes, the ejector rolls, and the separating plates all together transversely to the paper path. This is effected by providing a rod which connects the upper-tape deflection rollers, a separating shoe, ejector rolls, and a separating plate whereby they will all be transversely displaced together.

Abstract: Circuit arrangement for reducing recovery time of a thyristor formed with a semiconductor body having at least one emitter zone contacted by an emitter electrode and having at least one auxiliary emitter zone and a base zone contacted by an auxiliary emitter electrode, includes a shunt between the emitter zone and the base zone, a capacitor disposed in a line mutually connecting the emitter electrode and the auxiliary emitter electrode, the emitter electrode being the cathode and being disposed on the surface of the semiconductor body and electrically connected to the emitter zone, the shunt between the emitter zone and the base zone being formed through the capacitor, a series connection of a resistance and a diode being connected in parallel with the capacitor, the diode having a lower threshold voltage than that of an imputed diode formed by the cathode-sided emitter zone and the base zone of the thyristor, the diode of the series connection being poled with respect to the cathodic emitter electrode in the

Abstract: Si crystal lattice damage caused by neutron irradiation in homogeneously doping Si crystals with p.sup.31 is removed by an annealing process wherein the minimum temperature is adjusted in accordance with the make-up of the irradiation flux utilized during neutron irradiation and in accordance with the carbon concentration within the irradiated Si crystal.

Abstract: Circuit arrangement for reducing recovery time of a thyristor having a control electrode, a main emitter electrode and at least one auxiliary emitter electrode disposed between the main emitter electrode and the control electrode, includes two current sources, one of which delivers a pulse of one polarity and is connected to and between the control electrode and the auxiliary emitter electrode, and the other of which delivers a pulse of the other polarity and is connected to and between the auxiliary emitter electrode and the main emitter electrode.

Abstract: A device for determining the ion concentration of certain substances, or mixtures of substances, in swimming pool water by admixture of color forming chemical reagents comprising measuring containers and at least one reference container combined to form a row of containers which have a common side wall. An indicating screen with a plurality of fixed, differently tinted indicating windows associated with the individual containers and distributed over the height of the containers is arranged in front of the common side wall, and the indicating windows associated with the reference container or containers are provided with a standard coloration relating to that formed by the color forming reagents.

Abstract: A thyristor comprises a semiconductor element which has a control electrode and an arrangement which amplifies the control current and possesses an auxiliary emitter electrode. A housing encloses the semiconductor element and a control line, by means of which the control electrode is electrically connected to a conduit arranged in a housing wall, is included. A second control line is electrically connected to the auxiliary emitter electrode and to a conduit arranged in the housing wall. The housing is disc-shaped and comprises metal plates and an insulating ring and has a slot which is arranged in one of the metal plates and opens into a recess located opposite the control electrode and the auxiliary emitter electrode. The control line is positioned in the slot and has one end pressed against the control electrode under a spring bias action. The conduit is contained in the insulating ring and the second control line is also located in the slot in one of the metal plates.

Abstract: The present invention is directed to a thyristor having a configuration for educing turn-off time, said thyristor comprises a main thyristor portion having a main emitter electrode and a control electrode and an auxiliary thyristor portion having an auxiliary emitter electrode and adapted for amplifying the control current, the arrangement includes a voltage source connected to the auxiliary thyristor, and supplying the auxiliary emitter electrode with a current the direction of which is opposite to the direction of the control current.BACKGROUND OF THE INVENTION1. Field of the InventionThis invention is in the field of discrete semiconductor devices and is particularly directed to discrete thyristors.2. Description of the Prior ArtThe "turn-off time" of a thyristor is the time between the zero passage of a load current and the moment when the thyristor has regained its blocking capability.It is known that the turn-off time of a thyristor can be decreased considerably by provision of recombination centers.

Abstract: The present invention is directed to a thyristor comprising a body of semiconductor material with at least four zones of alternating conductivity type, of which the first zone represents an emitter zone and is provided with an emitter electrode, a second zone adjacent said first zone represents a base zone and is provided with an electrode, with at least one pn junction between the emitter zone and the base zone, and with at least one shunt bridging the pn junctions, this shunt being a current path located in the base zone or in the emitter zone, uninterrupted by any pn junction, located on the surface of the semiconductor body, and directly connecting the emitter electrode and the base electrode.

Abstract: The present invention pertains to a light activated thyristor which increases the current density of light-generated carriers by means of a low resistance path from an area of carrier generation in a base zone of a first conductivity type into a portion of an adjacent emitter zone of a second conductivity type. In one embodiment the low resistance path takes the form of an annular gate electrode affixed to the base zone and having a projection bordering the base-emitter PN junction. In another embodiment the low resistance path takes the form of a ballast segment disposed in the base zone, the ballast segment having an opening for funnelling the carriers to the base-emitter PN junction.

Abstract: A thyristor which may be controlled by light has a semiconductor body comprising at least four zones of alternating conductivity types. The first zone forms a main emitter, the second zone forms a base having a region which is provided to be exposed to light, and having an auxiliary emitter located between the light region and the main emitter. A second auxiliary emitter is located between the first-mentioned auxiliary emitter and the main emitter. The ratio of the effective edge lengths facing the exposure region, to the second auxiliary emitter and the ratio between the effective edge lengths facing the exposure region of the main emitter on the one hand and the second auxiliary emitter on the other hand are related to one another in such a manner that, prior to the turn-on of the first auxiliary emitter, the second auxiliary emitter and subsequently the main emitter turn on.

Abstract: A semiconductor switching device is described in which a control electrode is disposed on a base zone adjacent to an emitter zone. The control electrode has at least one straight edge portion parallel to an adjacent straight border edge portion of the emitter zone. The parallel edges are also parallel to a [110] crystallographic direction of the semiconductor crystal which has a <111> crystal orientation; thus providing optimum firing of the device.

Abstract: A thyristor is disclosed having a semiconductor body with at least four zones of alternate conductivity type in which the second zone has a control electrode and in which the first zone has a main emitter and first and second auxiliary emitters. The first auxiliary emitter is located between the control electrode and the second auxiliary emitter and the second emitter is located between the first auxiliary emitter and the main emitter. The ratio of the effective edge lengths of the first auxiliary emitter to the second auxiliary emitter and the ratio of the effective edge lengths of the second auxiliary emitter to the main emitter are matched to one another in such a manner that prior to the ignition of the first auxiliary emitter, ignition is initiated on the second auxiliary emitter, and then on the main emitter. The ratio of the effective edge lengths of the first auxiliary emitter to the second auxiliary emitter is .gtoreq.

Abstract: A thyristor including a semiconductor element which comprises a main thyristor and at least one auxiliary arrangement operative to amplify the control current, the main thyristor having a main emitter and the auxiliary arrangement having an auxiliary emitter, a base being common to both the main thyristor and the auxiliary arrangement, and pn-junctions disposed between the base and respective emitters, emitter electrodes being disposed upon the respective emitters, and a control electrode connected to the base, in which the edge length (1.sub.E) of the respective emitters is such that the current is i.sub.e > i.sub.u (i.sub.e1 22 i.sub.u1, i.sub.e2 > i.sub.u2 etc.), where i.sub.e is, in each case, the product of emitter length (1.sub.E) and a line current density j.sub.e of between 0.3 and 1.0 A/mm edge length and the current i.sub.