Patents Assigned to BBC Brown Boveri & Company Limited
  • Patent number: 4943840
    Abstract: A reverse-conducting thyristor having an integrated antiparallel diode, wherein an improvement of the switching characteristics is achieved by the fact that a field-controlled thyristor (FCT) is provided as the thyristor. According to a preferred illustrative embodiment, this FCT includes at the cathode side of the thyristor a plurality of alternately arranged n.sup.+ -doped cathode regions and p-doped gate regions, the cathode regions being separated from each other by troughs over the bottoms of which the gate regions extend.
    Type: Grant
    Filed: March 18, 1988
    Date of Patent: July 24, 1990
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventor: Peter Roggwiller
  • Patent number: 4909859
    Abstract: A process for increasing the oxidation resistance and corrosion resistance of a component made of a dispersion strengthened superalloy by means of a surface treatment, the object of which in every case is to produce or retain a fine-grained surface zone (5) while the core zone (4) of the component in all circumstances is forced to form coarse grains during the final recrystallization annealing in the temperature range between the recrystallization temperature and the solidus temperature. A fine-grained surface zone (5) is produced by cold-working the surface zone (3, 5) by shot-peening, surface milling or pressing or by heating the surface zone (7) to a temperature about 100.degree. to 140.degree. C. below the recrystallization temperature by means of a laser (9) or an arc (10) while the core zone is kept at less than 900.degree. C., or by application of a 10 to 50 .mu.
    Type: Grant
    Filed: February 26, 1986
    Date of Patent: March 20, 1990
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventors: Mohamed Nazmy, Hans Rydstad
  • Patent number: 4897785
    Abstract: The retrieval of stored data by means of a search word or search key by using, a hashing method. For this purpose, the search key is resolved into a polynomial having the form of ##EQU1## where i=control variable, k=its maximum value, w.sub.i =polynomial coefficient, p=a power of 2, m=number of search keys in an address table stored in the memory (7). The search process occurs by means of a recursive hashing function having the form of ##EQU2## using hashing function tables and address sub-tables stored in the memory. The address compared circuit, having three temporary memories for the polynomial coefficients w.sub.i, a multiplexer, the memory, an adder registers, a comparator, an edge-triggered JK-type flip-flop with an AND gate connected to its output, and a control unit makes it possible to achieve an inexpensive hardware implementation of the search method.
    Type: Grant
    Filed: June 17, 1988
    Date of Patent: January 30, 1990
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventor: Stefan Zuger
  • Patent number: 4829348
    Abstract: A field-controlled thyristor having a sequence of layers consisting of anode layer, channel layer and gate regions and cathode regions, which regions are alternately arranged at the cathode side, wherein an improvement in the turn-off gain is achieved by a p-type doping of the side walls of the troughs which separate the cathode regions from each other, and/or by an additional intermediate layer which has low p-type doping and which is arranged between adjacent gate regions.
    Type: Grant
    Filed: January 27, 1988
    Date of Patent: May 9, 1989
    Assignee: BBC Brown, Boveri & Company Limited
    Inventors: Bruno Broich, Jens Gobrecht, Peter Roggwiller, Jan Voboril
  • Patent number: 4819232
    Abstract: When a fault is detected in a processor, program execution in this processor is interrupted and taken up again by a standby processor from an earlier uncorrupted state, a recovery point. Such recovery points are specially provided in the program. A save copy of the state at the recovery points is created in each case in a state save unit by recording changes compared with the respective previous state. The data memory existing in the state save unit has pairs of memory words, in which arrangement the state at the recovery point last reached is in each case saved in one of the memory words and the current changes are in each case recorded in the respective other memory word. The memory words are accessed via pointers which are formed by a control logic from two check bits allocated to each memory word pair. Processing of the check bits and of the pointers is very fast. It is not necessary to copy data within the state save unit. The standby processor has direct access to the saved data.
    Type: Grant
    Filed: December 15, 1986
    Date of Patent: April 4, 1989
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventor: Lothar Krings
  • Patent number: 4818319
    Abstract: Process for reducing the water vapour diffusion in a plastics composite insulator consisting of several layers by incorporation of at least one mica-containing layer as diffusion barrier in the form of a surface or intermediate layer on at least one plastics body, constituting the composite insulator.
    Type: Grant
    Filed: March 10, 1986
    Date of Patent: April 4, 1989
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventors: Hans-Rudolf Beer, Helmut Britsch, Elias Julke, Tony Kaiser
  • Patent number: 4817145
    Abstract: A generator for generating ciphering sequences, including plural clocked subgenerators (.GAMMA., .psi., .PSI.) which, in turn, generate binary sequences at one or several outputs. To achieve high cryptographic security of the ciphering sequence (.omega..sub.t) generated by the generator, n+1, at least three subgenerator are used in an arrangement in which the clock of n of these subgenerators (.psi., .PSI.) is controlled in each case by at least one of the outputs of the (n+1)th subgenerator (.GAMMA.) either directly or via function generators (.DELTA.f(t), .DELTA.f (t)) wherein the sequences (.mu.f(t), .mu. f(t)) generated by the n sub generators are logically combined by at least one function, which function assumes both binary states with approximately the same frequency when its arguments pass through all possible values.
    Type: Grant
    Filed: October 15, 1986
    Date of Patent: March 28, 1989
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventor: Christoph-Georg Gunther
  • Patent number: 4811478
    Abstract: A lightning arrester with a monolithic, active resistor core made of voltage-dependent resistance material based on ZnO is produced by mixing and grinding the base materials Zno+metal oxides, producing pourable granules, filling into a silicone rubber tube and pressing cold-isostatically or radially into a moulding, sintering of the moulding into a self-supporting, monolithic resistor core, converting the resistor core, with an insulator by casting around, coating or painting with an epoxy resin, silicone material or concrete polymer or by drawing over a shrink-fit tube or by glazing. The resultant lightning arrester has a simple configuration, good reproducibility, cost-effective mass production.
    Type: Grant
    Filed: August 31, 1987
    Date of Patent: March 14, 1989
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventors: Gunther Maier, Joseph Mosele, Roger Perkins
  • Patent number: 4808246
    Abstract: A composite material 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 composite material.
    Type: Grant
    Filed: September 26, 1986
    Date of Patent: February 28, 1989
    Assignee: BBC Brown, Boveri & Company Limited
    Inventors: Joachim Albrecht, Thomas Duerig
  • Patent number: 4801554
    Abstract: A process for manufacturing a power semiconductor component having a component of this type is presented which has at least three consecutive layers and possessing a high current capacity and small power losses. For contacting the first two layers, the component has first second metallized contact planes, which impress a step-like structure onto a first surface of the component. The steps have a height of between 10 and 20 .mu.m and a width of between 20 and 300 .mu.m. The ratio between the surface area of the first contact plane and the surface area of the second contact plane is between 1 and 4. The first layer is heavily doped and has a maximum thickness of 8 .mu.m, and the second layer is lightly doped and has a maximum thickness of 40 .mu.m. According to the process for manufacturing the component, the surface structure according to the invention is produced essentially by a reactive ion-etching process with a single aluminum mask.
    Type: Grant
    Filed: February 26, 1986
    Date of Patent: January 31, 1989
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventors: Jens Gobrecht, Peter Roggwiller, Roland Sittig, Jan Voboril
  • Patent number: 4800257
    Abstract: An optoelectronic reading pen for scanning optically encoded information, applied to an information carrier, particularly in the form of a bar or line code, including means for illuminating the information carrier and an optoelectronic sensor which receives the light reflected from the information carrier and converts the reflected light into an electric signal, wherein ambient light from the environment of the reading pen is collected and used for illuminating the information carrier. Thus, the current intake is drastically reduced by the fact that, instead of an internal LED light source, light from the environment is used for illuminating the information carrier.
    Type: Grant
    Filed: February 11, 1987
    Date of Patent: January 24, 1989
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventor: Heinz Johner
  • Patent number: 4800363
    Abstract: A method and system for the transmission of data in an electric distribution system between a central controller coupled to a medium-voltage distribution line and at least one terminal coupled to a low-voltage wherein, the transmission of data within the medium-voltage distribution line takes place at a first carrier frequency (f.sub.1), and the data at the first carrier frequency is transposed to data at a lower second carrier frequency (f.sub.21, f.sub.22) for transmission from the medium-voltage distribution line to the low-voltage distribution line by means of a transponder. Due to this transposing of carrier frequencies, the system can be optimized with respect to the different channel properties of the two communication channels.
    Type: Grant
    Filed: January 2, 1987
    Date of Patent: January 24, 1989
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventors: Walter Braun, Walter Hagmann, Urs Hanselmann, Bruno Maibach, Peter Schranz
  • Patent number: 4797587
    Abstract: A triggering method for a thyristor switch which has at least two thyristors wired in series and a thyristor wired in antiparallel to each of these thyristors. The thyristor switch is triggered or cut off as a function of a specifiable on-off signal. At least a single triggering of a thyristor to be switched-on takes place at the earliest if a positive anode-cathode voltage is applied to it which exceeds a specifiable switch-on voltage limiting value. The method comprises generating a trigger standby signal if the on-off signal is in the switch-on condition and, with a specifiable minimum number of thyristors to be triggered wired in series, their anode-cathode voltage is greater than the specifiable switch-on voltage limiting value. At least a single triggering of each thyristor to be switched on takes place by means of a short-duration trigger pulse only during the duration of the trigger standby signal.
    Type: Grant
    Filed: March 30, 1987
    Date of Patent: January 10, 1989
    Assignee: BBC Brown, Boveri & Company Limited
    Inventors: Christoph Tschudi, Fritz Wittwer
  • Patent number: 4794624
    Abstract: In a method for clock synchronization of a signal receiver, the demodulated received signal is sampled in each of the subintervals over N time windows having in each case K subintervals (1A . . . 4C). In each case, the dispersion is calculated for the sampled values of N corresponding subintervals and the K dispersion values obtained are compared with each other. The optimum sampling time is derived from the position in time of the minimum dispersion value.
    Type: Grant
    Filed: December 8, 1986
    Date of Patent: December 27, 1988
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventors: Walter Braun, Joachim Habermann
  • Patent number: 4790980
    Abstract: A device and process for the generation of ozone using an ozone generator having two electrodes connected across the secondary winding of a high voltage transformer, the primary winding of which is connected to a converter which supplies thereto a square wave current of variable amplitude and variable frequency. A compensation coil is connected across either the primary winding or the secondary winding of the transformer. The ozone generator includes a solid dielectric and a gas path between its two electrodes. The inductance of the compensating choke and the operating frequency of the converter are selected such that the resonance frequency of the resonant circuit formed by the ozone generator and the compensation choke lies below the operating frequency of the converter current supply in any operating condition.
    Type: Grant
    Filed: June 12, 1986
    Date of Patent: December 13, 1988
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventors: Peter Erni, Gerard Kirsch
  • Patent number: 4785208
    Abstract: A low-inductance anode-cathode R-C circuit for a gate-turn-off power thyristor, including circuit diodes, capacitors and line connections for connecting the R-C circuit to a power thyristor. By reducing the spray inductances of circuit diodes, capacitors and line connections of the turn-off unloading circuit of a table-shaped power thyristor (Th), which can be designed for loads of 2500 V and 1000 A, its additional breaking current can be increased and the pulse-peak voltage of the first steep rise of the anode-cathode voltage across the power thyristor, occurring when it is switched off, can be reduced. R-C circuit diodes, capacitors and, preferably, also the power thyristor, have the same axial component direction, that is to say they are arranged axially parallel or coaxially with respect to each other in a low-induction R-C circuit arrangement.
    Type: Grant
    Filed: May 19, 1987
    Date of Patent: November 15, 1988
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventors: Claude Egger, Stefan Umbricht
  • Patent number: 4774716
    Abstract: A method for the transmission of digital data by means of phase modulation (PSK) and "frequency hopping", in which symbols are transmitted several times in different transmission sections as synchronization information for coherent demodulation, and wherein weighting factors taking into consideration the existence and influence of a disturbance source are calculated for each symbol. The symbol values are multiplied by these weighting factors before the values of corresponding symbols are linearly combined and utilized for evaluation.
    Type: Grant
    Filed: December 8, 1986
    Date of Patent: September 27, 1988
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventor: Walter Hagmann
  • Patent number: 4772342
    Abstract: A wrought Al/Cu/Mg type aluminum alloy of high strength in the temperature range between 0 and 250.degree. C., having the following composition:Cu=5.0 to 7.0% by weightMg=0.3 to 0.8% by weightAg=0.2 to 1.0% by weightMn=0.3 to 1.0% by weightZr=0.1 to 0.25% by weightV=0.05 to 0.15% by weightSi<0.10% by weightIn this artificially aged state, the yield strength (0.2% limit) reached is more than 500 MPa at room temperature, almost 400 MPa at 200.degree. C. and about 300 MPa at 250.degree. C. At 180.degree. C., the creep strength is still more than 250 MPa after 500 hours.
    Type: Grant
    Filed: October 24, 1986
    Date of Patent: September 20, 1988
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventor: Ian J. Polmear
  • Patent number: 4768075
    Abstract: A power semiconductor module including a cascade circuit of a low-voltage high-current MOSFET and of a bipolar semiconductor element, for example a field-controlled thyristor, GTO thyristor or Darlington transistor, as a hybrid combination. In this manner, it is possible to achieve a construction, which exhibits low induction and which saves space and which at the same time permits efficient cooling of the module.
    Type: Grant
    Filed: October 30, 1986
    Date of Patent: August 30, 1988
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventors: Bruno Broich, Jens Gobrecht, Peter Roggwiller
  • Patent number: 4767729
    Abstract: A voltage-dependent ceramic resistance (varistor) based on ZnO and other addition elements, mostly in the form of oxides, is prepared, in that the addition elements are added to a suspension of ZnO powder in H.sub.2 O as chemical substances in the form of aqueous, mutually compatible, non-separating solutions of organic salts, acids, complex compounds and/or colloids, the suspension/aqueous solution formed in this manner is dried in the presence of air in a spray dryer, the free-flowing powder/granules prepared in this manner are pressed to a body and the pressed body is subjected to heat treatment, in order to decompose the organic substances, convert them into oxides, remove the decomposition products, and is finally sintered by successive heating to 650.degree. C., 900.degree. C. and 1100.degree. to 1300.degree. C. The water-soluble chemical substances to be used are preferably organic salts such as formates, acetates, lactates, tartrates, citrates, ammonium citrates and ammonium tartrates.
    Type: Grant
    Filed: April 29, 1986
    Date of Patent: August 30, 1988
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventors: Maged A. Osman, Roger Perkins, Friedrich Schmuckle, Claus Schuler