Abstract: A thyristor exhibiting improved maximum current rise rates as a result of the relocation of the ignition front from the edge of the cathode emitter zone to inner cathode emitter areas. This relocation is effected by providing a relatively light doping of the anode zone beneath the thyristor gate and cathode emitter edge, and a relatively higher anode zone doping opposite and outside of the cathode edge, while not applying an anode electrode metal coating to the lightly doped area of the anode zone. The thyristor utilizes cathode emitter short circuit rings arranged such that the ignition front which occurs at thyristor triggering bypasses the short circuit ring immediately adjacent the cathode emitter edge, thereby increasing the thyristor voltage rise velocity, dU/dt.

Abstract: A probe adapted for selectively measuring either symmetrical or asymmetrical interference voltages or interference voltages between terminal and ground and utilizing first and second transformers having interconnected primary windings and tightly magnetically coupled secondary windings connectible with the interference measuring set for optionally measuring either symmetrical or asymmetrical voltages or voltages against ground, is disclosed. When measuring a balanced (symmetrical) voltage the terminals of the first transformer primary winding are coupled to the opposite poles of the specimen under test. When measuring an unbalanced (asymmetrical) voltage or a voltage with respect to ground, both terminals of the first transformer winding are connected in common to the pole of the specimen under test. In an cases a single ground terminal of the probe is connected to the ground of the specimen under test.

Abstract: A method of connecting metallic parts, and metallic parts so produced, by means of arc fusion welding by producing a low volume welding seam (narrow gap welding), wherein the workpiece parts to be jointed and forming a narrow gap are initially welded at their butt joint by means of, for instance, electron-beam welding, plasma-arc welding, laser-beam welding or argon arc-welding to produce a base seam with or without filler material, and thereafter the workpiece flanks forming the narrow gap are united by alternately depositing weld beads at first one and the other workpiece flank by submerged-arc welding.

Abstract: A process for the manufacture of an electrooptical display device including a circuit board and a liquid crystal display cell mounted on the circuit board, including forming a circuit board having at least one light conducting region; disposing the liquid crystal display cell adjacent the light conducting region of the circuit board; locating at least one light emitting element in the circuit board for illuminating the light conducting region; and attaching a semi-transparent reflector to the liquid crystal cell; wherein at least part of the circuit board is manufactured by combining a reflecting layer, which is produced by the deposition of a reflective material on a substrate or on one side of a mesh, with a light diffusing substance, by embedding these two materials together in a transparent polyester or epoxy resin.

Abstract: A polarizer of particularly small thickness for an electro-optically activated cell, wherein a polarization foil is provided between an adhesion layer causing the adhesion to the cell and a protective layer providing protection from external influences. The small thickness of the polarizer is achieved by the use of a particularly thin protective layer consisting of a curable lacquer of the type which is used for coating packaging foils in the foodstuffs packaging industry, thereby reducing the thickness of the polarizer provided with protective layers on both sides to much less than 50 .mu.m, without the polarizer sacrificing its outstanding resistance to chemical and mechanical influences.

Abstract: A method for controlling a gallium diffusion with at least one silicon wafer, wherein precisely dosed amounts of hydrogen, oxygen, and optionally nitrogen are mixed in a combustion chamber where the hydrogen and oxygen is converted into water vapor and hydrogen. The combustion chamber is connected to a source portion of the diffusion oven, wherein is contained a gallium oxide containing crucible. The water vapor, hydrogen (and nitrogen) mixture is then passed from the combustion chamber to the source over where the volatile sub-oxide (Ga.sub.2 O), is produced and then carried in a gas stream to the silicon wafer contained in a main portion of the diffusion oven for diffusion therein.

Abstract: A liquid crystal display, and process of manufacture therefor, emloying an integrated reflector internal to the liquid crystal cell, and consisting of a guest-host liquid crystal layer sandwiched between two cell plates and located between front and rear electrodes. At least the front electrode is composed of segments and parts of the reflector and/or rear electrode that lie opposite the conduction paths leading to these segments are at an electrical potential whose difference from the potential of the conduction paths is smaller than the threshold voltage of the liquid crystal layer used.

Abstract: A waveguide for the transmission of electromagnetic energy which has a low attenuation even with a small line cross-section realized by disposing in the interior of an electromagnetically shielded hollow cylinder, consisting of a substance having a low permittivity, a dielectric wire of a substance having a high permittivity. An E.sub.om -wave (m = 1, 2, 3 . . . , circular H field) is excited in the dielectric wire and the dimensioning of the dielectric wire is such, depending on the permittivities of the two substances and the particular operating frequency, that a TEM wave develops at least substantially in the space in the dielectric hollow cylinder. In the simplest case, the electromagnetic shield can consist of a metal tube and the dielectric hollow cylinder can consist primarily of air. Furthermore, the E.sub.om wave excited in the dielectric wire is preferably the E.sub.01 wave (TM.sub.01 mode).

Abstract: A monitoring circuit for determining whether or not m out of n a.c. input signals meet at least one predetermined set of signal characteristics is disclosed. The circuit includes n input terminals, each for receiving a different one of the input signals being monitored. A logic circuit monitors the condition of the n input signals and generates either an a.c. or a d.c. output signal as a function of the condition of the input signals. A d.c. output signal is generated whenever m out of n input a.c. signals have maxima and minima which both lie above or both lie below a predetermined signal range corresponding to at least one of the preset signal characteristics. An a.c. output signal is generated whenever m out of n input signals have maxima and minima which respectively lie above and below the predetermined signal range.

Abstract: A liquid crystal display for reflection operation with a guest-host liquid crystal layer disposed between two cell plates and respective front and rear electrodes, and with a diffusely divergent reflector integrated in the interior of the cell, at least the front side of the cell plate and the front electrode being transparent. The rear electrode and its supply comprise thick layers, and the reflector consists of metal parts insulated against one another and applied to the rear electrode and to the inner surface of the rear cell plate.

Abstract: An apparatus for connecting metallic parts, and metallic parts so produced, by means of arc fusion welding by producing a low volume welding seam (narrow gap welding), wherein the workpiece parts to be joined and forming a narrow gap are initially welded at their butt joint by means of, for instance, electron-beam welding, plasma-arc welding, laser-beam welding or argon arc-welding to produce a base seam with or without filler material, and thereafter the workpiece flanks forming the narrow gap are united by alternately depositing weld beads at first one and the other workpiece flank by submerged-arc welding.

Abstract: A tool for isothermal forging is disclosed. The tool consists of two die halves, at least one of which consists of an assembly of individual components whose side facing the workpiece is provided with a thin electrically insulating layer. The assembly of the die half from individual components occurs following forming of the components by casting and/or forging, and machining of the formed components. The forming of the die halves from separate components makes it possible to adapt the components of the die half to the particular working conditions in an optimum manner. The provision of an insulating layer on the individual components reduces the risk of local welding and nonuniform temperature distribution during inductive heating.

Abstract: The intermediate current transformer is replaced by a shunt resistor which bridges the secondary winding of the main current transformer and is of such magnitude that the secondary winding of the main current transformer is virtually short-circuited, but the voltage at the shunt resistor is still sufficient for evaluation in the electronic relay. The shunt resistor consumes only very little power and can therefore be located in the base of a plug-in device. This base, being a permanent part of the assembly, remains in circuit even when the relay is changed or removed for inspection or testing purposes.

Abstract: A blade structure for use in a fluid flow rotary machine wherein the blade profile is thickened within the head region and a cover plate is connected to the head end within the thickened region by means of a substantially loop-shaped welded joint which is made by use of a high-energy beam such as an electron beam applied to the surface of the cover plate. The starting and end portions of the welding run can be overlapped, and the intensity of the welding beam is gradually increased from the starting point of the run to eliminate any swelling effect and is gradually reduced towards the end of the run to prevent crater formation.

Abstract: A combustion chamber of a gas turbine engine has a combustion cowl and transition piece with at least one air gap provided therebetween. The air gap opens into an intermediate chamber having two throttles which are arranged oppositely with respect to one another. The two throttles are provided in a cooling jacket which is divided into two portions by the throttles. The air gap permits the combustion cowl and transition piece to expand freely with respect to each other. The two throttles are arranged so that fuel gas leaving the combustion chamber provides an injector effect to expedite the flow of a coolant such as air through the air gap.

Abstract: An apparatus and a method for producing dry, compressed air to be used for electrical switchgear, especially for high-tension switchgear, is disclosed in which humidity is extracted from the air in a subsequently arranged sorption dryer, with one portion of the dried air being used to regenerate a drying agent of the drying apparatus. The drying apparatus includes a cylindrical inner housing which is used for the pre-drying of the air, an outer housing which surrounds the former in jacket form for the final drying and a desorption volume. An electric heating rod protrudes concentrically into the inner housing and is covered by either a baffle device or a pipe so that a ring-gap is created between two components, with the ring-gap divided into two halves. The air is pre-dried in the first drying chamber prior to its entry into the compressor, with the temperature of the air being kept above the dew point during compression and cooling.

Abstract: The invention concerns a rotation apparatus for use with a rotating machine having a drive shaft. The rotation apparatus comprises an auxiliary shaft positioned in spaced relation relative to the drive shaft. Radial and axial bearings rotatably support the auxiliary shaft. Step-down gearing interconnects the auxiliary shaft and the drive shaft so that rotation of the former drives the latter. A rotational start-up mechanism comprising a hydrostatic motor and overriding clutch is drivingly connected to the auxiliary shaft to drive the latter. The hydrostatic motor and overriding clutch are mounted within a bearing housing of the turbine. The turbine drives a pump for supplying lubricating oil to the turbine bearings. A conduit also connects the pump with the hydrostatic motor so that the motor is continuously rotated once the turbine has been started.

Abstract: A support structure for a component of a vertical-axis machine such as its housing or a bearing spider thereof and particularly a rotary electrical machine which is expandable under operating conditions due to generation of heat. In order to maintain a stabilized concentric expansion of the component during thermal expansion the supporting structure is characterized by a system of plate springs arranged in substantially vertical planes and wherein the respective planes in which the springs are located lie tangent to the surface of at least one imaginary cylinder co-axial with the axis of the machine component, the radius of the cylinder being smaller than the mean radial distance of the plate springs from the axis of the machine component.

Abstract: A portable radio link system mast, particularly for use in the field, employing mast tube elements which are lifted, one after the other, by means of a lifting device installed in the head of the stand and, after a certain height is reached, are connected with always the next mast tube element. The lifting device consists of three frictionally self-locking pawls arranged on top of each other, a carrying pawl, a lowering pawl and a lifting pawl, which permit a slipless lifting, lowering and locking of the mast tube elements in connection with springs. A cardigan cam lever with a feeler stud draws attention to a wrong connection of the mast tube elements, and a mast tube element in the range of the lifting device can only be pushed out of the head of the stand after a correct contact is established with the following mast tube element.

Abstract: Slip-ring electrical contacts are avoided in a rotatable aerial or antenna of the type which is housed in a rotatable cage or basket having a supporting platform at the top of a mast, by constructing the electrical transmitting/receiving apparatus and the drive and control units for the rotating aerial at some region below the supporting platform for the rotating cage or basket, e.g., below deck in the case of a ship, and by transmitting the signal to or from the aerial by means of a wave guide concentrically arranged below and surrounding the axis of rotation of the cage, including a quarter wave joint surrounding the wave guide (with a clearance) on the platform, and connecting the wave guide to the aerial with the aid of a probe extending into the wave guide, two motor devices operating through differential gearing, all included in the region below the platform enabling the azimuth and elevation of the aerial to be determined.