Abstract: A frame start word derived by superframe formation is found by testing for the presence of a correct binary value combination each bit position in a time window having the length of as many bits as framing bits are spaced apart, with the inclusion of so many overframes that a decision can be reached on the possibility of a relationsip to the frame start word. If this is to be excluded the corresponding bit position is flagged and thereafter no longer taken into consideration. Otherwise, the next binary value of the corresponding bit position is inferred from the binary value present. The procedure is continued, always including the same number of overframes until only one unflagged bit position remains.

Abstract: A digital sine generator for providing fine resolution digital signals, more particularly 16-bit signals, includes a first computer for the selection of argument values and a second computer for the determination of the function values. Equidistant values or equally spaced points are selected as argument values on a periodic zig-zag characteristic so that for the function formation with the sine values in the range of the arguments between -.pi./2 and +.pi./2 is found to be sufficient. For the calculation of the sine values, a specific 7th order polynomial is used which can be implemented by five successive simple computations as a consequence of optimum selection of the coefficients.

Abstract: In a subscriber termination module for coupling a plurality of subscriber termination lines of a digital time multiplex telecommunications network, lines coupling a central portion and local portions individually allocated to at least one subscriber termination line are selectably utilized for the transmission of status setting information to the local portions for setting different operating conditions and for serial transmission, that is, successive transmission of information to be supplied to the individual local portions as well as for simultaneous information transmission from the local portions to the central portion, that is, parallel information transmission.

Abstract: A modulation-doped field effect transistor includes an undoped semiconductor layer and an arrangement for supplying charge carriers into a region of the semiconductor layer adjacent one side. An arrangement is provided for locally modulating hole and electron density in another region adjacent the other side of the semiconductor layer in a repeating pattern of alternations so as to inhibit current flow in the direction of the alternations.

Abstract: A circuit arrangement, with a doubled central switching matrix to which two line trunk groups having a sub-switching matrix each and a group control unit each, are allocated to each other in pairs via two PCM-lines. The line facilities which are individually allocated to the one and the other of the two line trunk groups and which are connected to the sub-switching matrix of their own respective line trunk group during normal service, are switchable during emergency service of one of the two line trunk groups to the sub-switching matrix of the respective other line trunk group. In order that no interconnected calls are interrupted, each local control unit stores the call data of all interconnected calls during normal service.

Abstract: In a process of digital to analog conversion, use is made of a network comprising capacitors (C through C'/16) which are binary-stepped in their capacitance, and whose lower terminals, depending upon the binary value of the allocated bit of a digital signal to be converted, are switchable to a reference voltage source (V.sub.ref) or to ground potential and thus either codetermine or do not codetermine the value of the network output voltage representing the analog signal. In order to achieve a monotonic and possibly linear converter characteristic when converting into bipolar signals, the network is so switched that, when generating positive and negative analog values of the same order, it always involves the same capacitors, and no additional capacitor is required for change redistribution.

Abstract: A solar protection device includes slats of refractive material rotatable about a longitudinal axis, having an even, flat upper side and having on their lower side prisms arranged serially without gaps and running parallel to the longitudinal axis. In order to maintain the condition for retroreflection with variations of the sun's position, the angle of inclination to the horizontal of the slats must be readjusted from time to time, at least seasonably. For automatic adjustment thereof a light sensing arrangement of two light sensors arranged oppositely on both cathetal legs of one of the prisms whose hypotenuse is formed by the upper side of the rotatable slat. Control by a drive and associated electronics is undertaken and continued as long as solar rays impinge on one of the light sensors with intensity exceeding a predetermined illumination level.

Abstract: A method is disclosed for measuring telephone dial pulse parameters independent of telephone subscriber line length. To avoid distortions resulting from varying subscriber line lengths, there is performed during the first pulse interval of a dial pulse series to be measured, a voltage measurement with results in a value that depends on the line length, and, in accordance with this value, the times measured for pulse interval and pulse duration of the dial pulse series are corrected.

Abstract: After connecting a device to the switching device through device-specific connect command and transmission of a start command as well as transmission back of a start command acknowledgement signal, the connect command is partially or slightly changed and transmitted again, whereupon the switching device transmits a stop command to the particular device. The stop command is responded to by the particular device with a stop command acknowledgement signal transmitted back only, if after established connection it has received a start command before a stop command. The activation error is recognized in that after output of the changed connect command and the stop command transmitted thereupon each time, a stop command acknowledgement signal arrives in the switching device.

Abstract: Coupling circuitry for multistage coupling fields in telecommunications networks, especially time-multiplex telephone switching systems, with switching matrices and intermediate lines that connect them from coupling stage to coupling stage.The multistage coupling field has intermediate-line wiring wherein a number of intermediate lines extends in parallel in a group of intermediate lines from every switching matrix in the first coupling stage to every switching matrix in the second coupling stage, the number being large enough to prevent interior blockage even while multichannel connections are being established.

Abstract: For subscriber termination circuits of a digital time multiplex telecommunications system comprised in a group, an injection circuit is provided, individual to a group. The injection circuit comprises a switch exhibiting a gradual change of state both in switching on and switching off for providing timing for meter pulses provided by a meter pulse generator. The meter pulses are applied to the individual subscriber termination lines in a multiplex manner by way of contacts as well as test relays already present.

Abstract: A power switch device comprises an asymmetrically blocking thyristor (ASCR), with which a diode is connected in series. The ASCR as well as the diode require only about one half the central zone thickness as compared with a symmetrically blocking thyristor laid out for the same blocking voltage in reverse direction (U.sub.RRM). For the series connection of the ASCR and diode, this results in a much lower blocking delay charge (Q.sub.rr).

Abstract: For checking authorization of access to a signal processing system (SVS) from designated peripheral units (TE, BS) connected with the system, for the purpose of transmitting and, if the occasion arises, receiving signals, it is provided that a keyword is entered in the signal processing system for each peripheral unit. Such a keyword is always derived from a code number allocated to a respective peripheral unit and from identification data which is freely selectable for the respective peripheral unit. In the event of an intended access by a peripheral unit, the code number transmitted by said peripheral unit and the identification data pertaining thereto are combined with the keyword allocated to the respective peripheral unit.

Abstract: The switching network is tested by comparison of bit streams coming from the double part switching network parts; other parts of the exchange are tested by parity checking. Evaluation takes place at a central location; when a parity error is found in the transmission in a direction of transmission, the parity bit generated for transmission in the other direction of transmission is falsified.

Abstract: The invention relates to a circuit arrangement for the indication of loop closure during the ringing condition for a subscriber circuit which is connected to the exchange of a digital time multiplex telephone system by way of a subscriber termination circuit comprising a subscriber line interface circuit which, in part, provides the ringing supply and signalling, and a signal processing unit which, in part, provides for analog to digital conversion and digital to analog conversion as well as for filtering.The circuit arrangement includes a changeover switch, by way of which, a signal representative of the subscriber termination line current is applied to the signal processing unit during the ringing condition, in place of the speech signal present during the speech condition.

Abstract: As a function of the occurrence of first square-wave signals the circuit arrangement generates a time window and monitors the appearance of second square-wave signals during the time span defined by the time window. If the second square-wave signals appear during the time window, appropriate output signals are generated. The circuit arrangement contains an integrator which is reset by the first square-wave signals and released subsequently. A comparator compares the voltage at the integrator with two threshold values. If the first threshold valve is exceeded, the time window is opened, and it is reclosed if the second threshold value is exceeded. The threshold values are generated by means of a switchable voltage divider. This voltage divider is switched by means of a flip-flop if the voltage at the integrator exceeds the first or second threshold value, respectively.

Abstract: A circuit arrangement for telecommunication installations, in particular, telephone exchange installations is disclosed in which type information is sent ahead of each communication to be transmitted. In bidirectional communication transmission with different possible communication types, type information announcing the respective communication type is sent ahead. In the receiving equipment the beginning of the arrival of type information is recognized and immediately, that is, almost simultaneously, an assortment of type-specific message corresponding to each of the possible communication types is transmitted in the opposite direction, of which each indicates the readiness or non-readiness for receiving a communication of the respective type.

Abstract: A heat dissipating housing (W/Gl/G) for a circuit component (IC) consists of at least one bottom tub (G) and a cover (W) having a planar cover face. A frame-shaped portion of this cover face serves as a bearing surface (TF) for meeting a planar bearing surface (TF) of the sidewalls (G1) of the bottom tub (G). Both bearing surfaces (TF) are finally fastened together. At least parts of the cover's outside surface (W) are cooled in operation by a cooling medium (KL), dissipated heat being conveyed from the circuit component (IC) via a stiff heat conducting body (SC1, SC2) and a good heat conductor element consisting of elastic material (FE/WS/WL) to the cover (W).

Abstract: Information(s) to be processed for call set up, as well as for testing and maintenance are supplied to a switching unit. The former are prioritized. A loadability measuring circuit, which compares actual-loading with reference-loading during leveling longer period, short term fluctuations, and continuously sets an adjustment standard related to the inflow of information, which is pre-supplied to a corresponding counter, for continuing inflow measurement, then measures loading caused by information of both kinds, measures instead, average corresponding reduced reference-value dependent, reference-actual comparison, for the case where this loading is too high, only the loading dependent upon call set up information to be processed. The adjustment standard is only reduced when the latter loading is too high, it is increased instead when the latter loading, as well as the loading dependent upon both kinds of information is too low.

Abstract: In power MOSFETs the source zone (5) and the channel zone (4) must be contacted by a common contact (15). If the contact material is aluminum and if the channel zone (4) is n-conductive (p-channel MOSFET), a surface region (8) of the channel zone (4) is additionally n-doped through an opening (6) in the source zone (5) thereabove with a dose of .gtoreq.5.times.10.sup.14 atoms cm.sup.-2. The aluminum contact (15) contacts the channel zone (4) at this region (8) thereby forming a purely ohmic contact to the channel zone.