Abstract: A method for controlling the carrier of an amplitude-modulated transmitter, wherein a saving in carrier power with simultaneous minimum dynamic distortions is achieved by digitizing the useful signal and digitally processing all control signals. The circuit for carrying out the method contains a digital computing circuit which calculates from the digital amplitude values of the useful signal a carrier-control value which controls the carrier level via a digital switching amplifier.

Abstract: For improving the dynamic characteristics of semiconductor components required to absorb high reverse voltages only in one polarity (diodes, reverse-conducting thyristors and asymmetric thyristors), in many cases structures having an n base consisting of two layers are used. In order to improve the reverse-voltage capability, it is proposed, in a semiconductor component having at least one pn.sup.- n sequence of layers, to select the thickness (S) and the doping of an n stop layer (4) in such a way that the following applies: ##EQU1## where e=elementary charge, .epsilon.=dielectric constant of the semiconductor, N.sub.D =donor concentration, X=path coordinate, 0.8.ltoreq.k.ltoreq.1.0 and E.sub.n =field strength at the n.sup.- n junction. The effect of this measure is that the geometric conditions of the edge chamfering are less stringent. The edge can also be shaped by means of conventional etching processes.

Abstract: In turbo-generators with hydrogen-cooled rotor windings, one-piece end casings are used to avoid complicated sealing positions. These end casings are strongly ribbed in a radial direction and present difficulties when installing the shaft seal (19). Furthermore, they do not permit any inspection openings in the ribbed end casing. Both have the final result of causing an increase in the machine length. Due to the pot-type design of the end casing (1) with a vertically extending channel-type recess (9) having a width greater than the rotor outer diameter, the assembly of the splert ring (19) is facilitated. The channel walls (7, 8) stiffen the end casing and provide niches which are accessible from the end face of the machine via inspection openings.

Abstract: The valve intended for direct connection to the outer casing of a double casing steam turbine has a diffusor located in the valve housing, which diffusor protrudes through the outer casing into a connection stub pipe of the inner casing, where it is connected with a flexible seal to the inner casing. In a preferred embodiment, the diffusor sits with a cylindrical step in a corresponding bore of the valve housing, the valve housing consisting of ferritic cast material and the diffusor of austenitic steel, whose coefficient of thermal expansion is greater than that of the valve housing material. The diffusor, which sits loosely in the cold condition, expands more than the valve housing when the turbine becomes hot so that the diffusor is then firmly held in the valve housing.

Abstract: Very finely granular metal powders are produced by atomizing a liquid jet of metal by means of a gas jet which, in addition to a continuous band of sound frequencies, contains at least one discrete sound frequency which is at least 5 decibel above the average intensity of this band, and which is generated in a rotationally symmetrical device by means of a nozzle (4) which has the shape of a hollow cone and by means of an annular resonance space (7) with an annular edge (6) and is projected concentrically against the liquid jet of metal at a total opening angle of an average 35.degree. to 55.degree.. The atomization zone of the gas jet should preferably contain at least three discrete sound frequencies which are each at least 10 decibel above the sound intensity of the continuous band.

Abstract: A coupling for a light-conducting fiber, including a metal coupling body, a first device for holding a light-conducting fiber disposed in one side of the metal body and, a second device for holding an opto-electronic transmitting element provided in the other side of the metal body. An opto-electronic transmitting element located in a housing is thermally coupled to the coupling body via a metal cap placed on the housing. As a result of this coupling, the thermal loading of the transmitting element is considerably reduced. For purposes of electrical isolation, an insulating layer can be additionally applied between the metal cap and the coupling body.

Abstract: A thyristor circuit including a primary winding and at least one secondary winding and first and second bipolar thyristor switches connected across respective connections of the secondary winding. The first bipolar thyristor switch bridges N.sub.1 turns of the secondary winding, while the second bipolar thyristor switch bridges N.sub.2 turns of the secondary winding, wherein N.sub.2 is less than N.sub.1. The product between the maximum forward current of the second bipolar switch and the number of turns N.sub.2 is greater than the product between the latching current of the first bipolar thyristor switch and the number of turns N.sub.1 thereof. The second bipolar thyristor switch thus makes it possible to short-circuit the portion of the secondary winding bridged thereby, for operation as a switchable choke, e.g. in a reactive compensator, or as a variable power supply when supplemented by additional components.

Abstract: To reduce unwanted current oscillations such as, for example, of the second harmonic of the system frequency (f.sub.o), the firing angles (.alpha.1, .alpha.2) of a link-circuit rectifier (1) and of a link-circuit inverter (2) are compensatingly acted on in push-pull mode. For this purpose, a direct-current link-circuit current signal (S5, S5'), which contains the instability or the current oscillation to be compensated, is fed by means of a current detector (5, 5') to a bandpass filter (16, 16', 16") which is tuned to the frequency (f.sub.o, f.sub.x) of the respective current oscillation. The phase of a bandpass filter output signal (S16) is shifted by 90.degree. trailing in a 90.degree. phase-shifting section (15, 15', 15"). A compensating signal (S15,S15', S15") obtained in this manner is fed to first and second function generators (13, 13', 13"; 14, 14', 14").

Abstract: An apparatus for the monitoring of physical quantities on systems for example for driving a quick-closing valve in turbines, wherein the monitoring itself is performed by monitoring channels which are interconnected in a majority-determining switching logic, primarily 2 of 3 system. The monitoring channels (I, II, III) are formed by a system-dependent number of identical solenoid valves (1, 2, 3).

Abstract: An article in rod, tube, strip, sheet or plate shape with reversible thermomechanical properties is produced by joining of at least two parts consisting of a total of at least one shape memory alloy having a two-way effect, whereby each part has a memory effect by itself. In the case of at least two shape memory alloys (1, 2) with different transition temperatures but the same mode of movement, the joining of the individual parts can take place prior to the deformation in the low temperature range necessary to inducing the two-way effect. In the case of differing types and degrees of movement of the individual parts (25, 26), their joining can first be accomplished only after the individual deformations of each part for itself in the low temperature range are accomplished regardless of how many shape memory alloys with different transition temperatures are used in the structure of the article.

Abstract: The laminated stator body of a large turbo-generator consists of a stack of laminations (1) comprising laminated compression plates (2), which stack is clamped together by means of tie plates (3) and tension bolts (8). The end face of the compression plate is stepped in the axial and radial direction. The tie plates have either a contour which matches the outside contour of the compression plate (2) or are smooth and, in the latter case, are supported by arch pressure in the radial direction. The elaborate machining of the compression plate end face, resulting in the elimination of lamination shorts, can thus be omitted without impairing the electrical and magnetic effects of the laminated compression plate on the end field of the machine.

Abstract: Bottom electrodes (6) of direct current arc furnaces, especially during the overheating phase of the melting process, are subjected to very high thermal stresses. As a result of a melting bath flow brought about by electromagnetic forces, the heat supply from the overheated melting bath (13) to the bottom of the electrode(s) (6) is increased still further. This is manifested in a melting back of the metallic component (6') of the bottom electrode in the direction of the furnace crucible base (4). When both the metallic component (6') and the non-metallic refractory component (7') of the bottom electrode (6) are arranged in the direction of the electromagnetic field, that is, in the peripheral direction of the bottom electrode (6), the length (l) of the electrode component is greater than its width (b).

Abstract: In a dry etching process for patterning a substrate (2), an etching mask (4) consisting of a chemically deposited oxide, for example Al.sub.2 O.sub.3, is used and the etching is carried out in a fluorine-containing plasma. By this means, etching selectivities of more than 100 are achieved for a substrate (2) of silicon.

Abstract: A liquid crystal display based on the bistability effect, wherein the distance between the support plates is smaller than 10 .mu.m and the total twist of the liquid crystal is between 180.degree. and 360.degree., preferably about 270.degree.. Over the entire viewing area of the display, randomly distributed spacers are provided. Because of these measures, the range of the bistable action is so narrowed that the display can be driven with operating voltages outside this range, using conventional multiplexing techniques. A high degree of multiplexing with short switching times and excellent contrast is obtained. The range of viewing angles is very large and independent of the direction of illumination.

Abstract: A rotor of an electrical machine having directly cooled rotor winding, including winding conductors forming a conductor bundle, located one above the other in respective grooves and fastened therein by respective groove wedges, the winding conductors each having at least two adjacent half cooling ducts extending in the longitudinal direction of the conductors. Provided in a central section of the rotor assembly are two gas outlets offset relative to one another in a peripheral direction of the rotor and in which the cooling ducts are interrupted by separating means. At each interruption point, the respective half cooling duct is in connection with a respective radially extending duct, which ends at the surface of the rotor. In order to avoid increases in temperature in the region of the gas outlet, the gas outlets of a conductor bundle are offset retative to one another in the longitudinal direction of the conductors. The radial ducts emerge into holes penetrating the groove wedges approximately radially.

Abstract: In a large turbo-generator comprising a laminated stack (6) which has on its outside axial grooves (7) which are distributed over the entire circumference and which is there suspended in a housing (1) by wedges extending in its longitudinal direction, the wedges (8) are joined to a wedge carrier (4) which extends parallel to them and is fixed at the housing (1). The wedges are constructed of several parts and have a central center part (8) which is detachably connected to the wedge carrier (4) and which is essentially used for radial support. As support in the circumferential direction, clamping devices, for example in the shape of double inclined wedges (9a, 9b) are provided which are arranged in pairs between the groove side walls and the wedge center part and which are located completely inside the groove (7) and which can be actuated from the front of the completely laminated stator. In this manner, mounting openings in the housing (1) become superfluous and laminating is facilitated.

Abstract: The gas-blast switch preferably suitable for the switching of medium voltage contains two switch pieces (2, 3), which are movable relative to one another in a housing (1), filled with insulating gas, and define an arc-quenching zone (4) during switch-off. Moreover, the arc-quenching zone (4) is defined by an insulating body (8) in which an annular channel (15) is recessed. The annular channel (15) connects the arc-quenching zone (4) with a chamber for the storage of heated-up insulating gas. Additionally compressed insulating gas can be fed to this storage chamber (9) from a compression chamber (10) of a compression device which is actuated during switch-off. In this switch, the switch-off capacity is to be increased by improving the quality of the insulating gas located in the storage chamber (9). This is achieved in that the compression chamber (10) and the storage chamber (9) are connected to one another via a flow narrow point (18).

Abstract: An air storage gas turbine having a turbine, a combustion chamber supported on the external casing of the turbine and a hot gas casing leading from the combustion chamber to the blading. The hot gas casing is surrounded by an intermediate space. An inlet casing emerging into the intermediate space is provided with main air supply lines, in each of which is located at least one control device and one rapid shut-down device. The inlet casing forms an annular chamber and is provided with radial supply openings, a vertical outlet opening and axial outlet openings. A blow-out passage communicates the vertical outlet opening with a blow-out valve.

Abstract: An amplitude-modulated transmitter wherein the carrier value (T) is controlled in accordance with an improved HAPUG (controlled-carrier) method. Increased energy saving with simultaneous increase of the signal-to-noise ratio at the reception site is achieved by controlling the carrier along a static characteristic (SK) which begins, with a decreasing modulation level (P), with a residual carrier value (R), drops with increasing modulation levels to a minimum carrier value (T.sub.min) and passes into an ideal carrier-control characteristic only above a first level value (P.sub.1). Additional dynamic control results in a reduction in cross-over distortions.

Abstract: The compressor of the coal-fired air storage gas turbine power station is connected by a main air duct to a fluidized bed combustion chamber and an air storage cavern. There is one clutch in each case respectively between the compressor and the electrical machine and between the latter and the turbine. In order to maintain the fluidized bed firing even in the case of pure pumping operations, a low load air duct with a shut-off unit is provided, the low load air duct connecting a pressure stage of the compressor to the main air duct at a position before the fluidized bed combustion chamber. During pumping operations, the fluidized bed continues to be fired at low load by closing a throttle unit in the section of the main air duct leading to the fluidized bed combustion chamber with simultaneously open shutoff units respectively in the section of the main air duct leading to the air storage cavern and in the low load air duct.