Abstract: The invention relates to a method and a circuit arrangement for controlling power valves included in at least one converter (2,4) forming part of a converter circuit which on its input receives at least two DC voltages (U1,U2) and transmits current pulses respectively corresponding to these DC voltages to a common load (R.sub.L) via a common output filter (L1,C1), said controlling aiming at keeping the input DC voltages equal.A control circuit (44) regulates the input voltages by shifting the starting times of the respective current pulses with respect to each other. Preferably, and particularly in continuous operation, the respective current pulses are shifted with respect to each other essentially without changing there widths.
Abstract: Synchronization is maintained between a regional radio transmitter/receiver and a remote transmitter/receiver communicating across a TDMA channel by detecting time misalignment of communications from the remote transmitter/receiver to the regional transmitter/receiver, commanding the remote transmitter/receiver to adjust its transmission timing, and, until the remote transmitter/receiver has adjusted its transmission timing, looking for a synchronization pattern accompanying transmissions by the remoter transmitter/receiver during two discontinuous time intervals, one centered about a time of occurrence of the synchronization pattern before the command and another centered about an expected time of occurrence of the synchronization pattern in response to the command. Effectively, what would otherwise be a disadvantageously wide time window is split into two advantageously narrow time windows to avoid detection of false syncs. Fewer false syncs are detected, and speech quality is increased.
Type:
Grant
Filed:
July 21, 1992
Date of Patent:
July 20, 1993
Assignee:
Telefonaktiebolaget L M Ericsson
Inventors:
Tomas Backstrom, Anders Sandell, Peter Wahlstrom
Abstract: There is disclosed a flange or pressure vessel closure device and method for deheading a coke drum. The coke drum deheading device has an annular retaining element spring biased from a lower flange of a coke drum, and a plurality of hooks which extend from the retaining element to engage a cradle holding the bottom head against the flange. When it is desired to disengage the head from the flange, the hook retaining element is moved by a first set of cylinders toward the flange to release tension from the hooks so that they can be disengaged from the bottom head by pivoting them outwardly using a second set of cylinders or other hook pivoting means. The bottom head can then be disengaged from the flange, lowered and moved laterally away from the coke drum on a hydraulic table.
Type:
Grant
Filed:
November 1, 1991
Date of Patent:
July 20, 1993
Assignee:
The M. W. Kellogg Company
Inventors:
Joseph Fruchtbaum, Frederick B. Kronmiller
Abstract: A digital communication network adapts a conventional MIL-STD-1553 aircraft multiple weapons rack for carriage of smart weapons. The network is a communications, power, and signal management interface circuit which permits an existing single pylon wing RT/sub-bus to control a plurality of additional smart RT's. The network utilizes a sub-bus which includes an RT and a bus controller for the multiple stores. The output of the RT/sub-bus is divided to create a plurality of inputs to the additional RT's to establish a power and communications link with the aircraft controller. The network includes a processor which receives coded digital communications from the controller and selectively rebroadcasts those communications to one of the smart weapons on the rack designated by the coded communication.
Type:
Grant
Filed:
June 19, 1992
Date of Patent:
July 20, 1993
Assignee:
M. Technologies, Inc.
Inventors:
Maureen P. McGlynn, William D. Meiklejohn
Abstract: In a receiving circuit of a mobile telephone apparatus the incoming baseband signals are demodulated and equalized so as to compensate for deficiencies (multipath propagation) of the radio medium between base station and mobile telephone apparatus. It is not, however, always necessary to equalize the demodulated signals, for instance at low symbol rates or in the case of monopath propagation. According to the invention, time dispersion of the received signals is estimated prior to demodulation, and demodulation with equalization (3a) is effected when the time dispersion is established to be higher than a given value, whereas demodulation without equalization (3b) is effected when the time dispersion is lower than this value. This will enable the power consumed by the receiving circuit to be reduced, particularly in the listening mode of the apparatus.
Abstract: A method and apparatus for achieving reliable transmission of signalling messages in a cellular system in which the frequency plan, frequency/time slot allocation plan, code channel allocation plan, or dynamic/adaptive channel allocation rule of the system is violated by allowing adjacent base stations to reuse particular frequencies/time slots/channels for signalling a particular mobile station. In situations where signalling messages, such as handoff commands, which are communicated between a base station and a mobile station are not properly received by the mobile station, an alternate communications channel will be established to ensure the reception of these messages. The alternate channel is provided by repeating the message through a channel associated with a base station which has better radio characteristics. The channel selected for transmission of the message by the new base station will be on the same frequency/time slot/code as used by the established connection.
Type:
Grant
Filed:
October 25, 1990
Date of Patent:
July 20, 1993
Assignee:
Telefonaktiebolaget L M Ericsson
Inventors:
Walter Ghisler, Steinar J. E. A. Dahlin, Harald Kallin
Abstract: Barium peroxide oxidizer, together with a transition metal from Group I, III, IV, V, VII or VIII or compound thereof is used as stoichiometric reagent in the oxidative dimerization of hydrocarbons having three or four carbon atoms. Barium peroxide oxidizer, together with a transition metal from Group I, III, IV, V, VI, VII or VIII or compound thereof is used as stoichiometric reagent in the dehydrogenation of hydrocarbons having three or four carbon atoms.
Abstract: Symbol sequences having synchronization sequences are transmitted over a radio channel. Received signals are sampled in signal sampling time points (n) and by correlation a channel response (C.sup.2) is obtained. The impulse response is sampled (T.sub.s) over a period (M.times.N) corresponding to time dispersion of the channel. For separate samples with separate start points (n), channel estimates are obtained (n=0, 2, 4, 6, N=1, 3, 5, 7. . .) whose energy values are calculated, and the estimate (n=8, 10, 12, 14) with the largest energy is selected. The first time point (n=8) in this estimate is selected as sampling time point for the symbol sequence. Alternatively, the signal sampling time point (n=9) with maximum energy value (C.sup.2 max) is selected. By comparing the energy values either one of these signal sampling time points (n=8 , n=9) can be selected as the sampling time point for the symbol sequence. For consecutive sequences, an average value for the sampling time points is calculated.
Abstract: A method of detecting the division of a radar target can detect a target, for instance caused by the release of a weapon from an aircraft which is tracked by a monopulse radar whose antenna is aligned onto the target with the aid of azimuth and/or elevation difference signals. Division of the radar target can be detected irrespective of whether the target is equipped with and uses an interference transmitter, by establishing a search channel in the radar difference channels. This channel has a sensitivity which is very low in a direction towards the tracked target, but which increases rapidly in directions which deviate somewhat from the direction towards the target. The search channel can be established by comparison of the absolute values of the signal levels in the difference channels with a threshold value.
Abstract: A multi-roll calender for treating a web material, of the type which develops a linear force, has at least two rolls stacked one above the other in a press plane. A lower roll is constituted as a sag-compensation roll. The other rolls in the calender stack are all equidistant relative to the sag-compensation roll, i.e., they are supported the same distance away from the two supports of the rolls. One of the outermost rolls (either the top or the bottom roll) is fixed in a stand while all the other rolls are movably mounted. The moveable rolls can be acted upon by support forces acting in the plane of the stack. The support forces and the internal pressure of the sag-compensation roll are adjustable via a control device, e.g., a computer, so that even when the rolls sag, the linear force distribution of the rolls is identical over their width.
Abstract: Novel precipitated silicon dioxide abrasive compositions which can be incorporated into therapeutic toothpaste compositions containing soluble fluoride salts are disclosed. The abrasives comprise low structure, high fluoride compatible amorphous precipitated silicon dioxides (silicas) having a controlled refractive index for use in low water clear gel dentifrice applications. Also provided are methods for preparation of the novel silicon dioxide abrasives and resulting toothpaste formulations containing such abrasives.
Abstract: The invention concerns a coupling for the detachable connection of two components, preferably a shaft with a hub, which for transmission of a torque are rotatably connected with each other by form-fit. When using such plug or form fit connections such as between a roll journal and a coupling box in a rolling mill, large tolerances must be expected that express themselves in peripheral directions and have adverse effects on the surface integrity of the rolled material. The invention provides for a clamping element which preferably can be inserted in the hub, acted upon by hydraulic fluid to keep the shaft in place relative to the hub. The clamping element is of a two-part design and can be filled with hydraulic fluid through appropriate devices, so that the hub is tightly fastened on the shaft upon assembly. For removal of the hub from the shaft, the pressure in the clamping element is simply relieved.