Abstract: The pulse transformer consists of a closed toroidal core (30), the primary winding (31) and secondary winding (32) of which are fashioned as multilayer, flexible printed circuit boards. These circuit boards have the shape of flat strips and are bent into loops. By means of pins (36-39 and 46-49, respectively), they are connected mechanically and partially electrically to a supporting printed circuit board (11). The pins connect the conductor tracks of the central layer of the flexible printed circuit boards with respectively one winding, whereas the upper and lower conductive layers shield the windings against electromagnetic interferences coming from the outside.The pulse transformer is suitable as an isolation transformer for the transmission of rapid digital signals arriving, for example, via a coaxial line (20).

Abstract: A mosaic printer is made secure from unauthorized interception of data by falsifying the needle drive pulse current magnitude and sequence so that electromagnetic leakage radiation cannot be used to determine the alphanumeric data being printed. This falsification is accomplished by a compensation device having compensators energized each print cycle in addition to the printer needle drives in a reciprocal or a pseudorandom manner. The compensators have current consumption characteristics nominally identical to the needle drives and produce substantially identical radiation pulses, making it impossible to correlate the radiated pulse format with the symbol being printed.

Abstract: A lever arm adapted to hold a stylus or the like on one end is rigidly connected at the opposite end in spaced parallel relation to a second arm, and a shaft perpendicular to both arms through the rigid connection provides a pivot axis therefore. An opening in each arm in registered relation, at equal distances from the shaft, receive tabs on opposite edges of a plate-shaped pivoting armature which suspend it between the two arms and position it in a diagonal neutral position in a gap between two axially opposed, individually switched solenoids, each having a contact area and diagonally opposing abutments for contacting the armature biased against them in neutral position by at least one spring, whereby actuation of the solenoids moves the arms to three different stable positions.

Abstract: A resilient wire attachment clip has two respective longitudinally extending; elongated, loop portions positioned in two mutually parallel planes, each of the loops formed by an internal limb and an external limb connected by a resilient arc portion that extends through a slot in a housing wall, the external limbs of the two loop portions normally lying within a pair of parallel grooves on the exterior of the housing wall with the ends of the external limbs connected by a transversely extending portion that is spaced outwardly from the housing wall, the internal limbs of the two loop portions have hook-shaped free ends which with slight prestress engage two abutments on the interior of the housing wall to support the clip between the two abutments and the interior surface of the housing wall at the point of an interiorly directed bend in the internal limbs, with the major portion of the diameter of the loop arc portions positioned interior of the housing wall.

Abstract: A segment digital/analogue converter for conversion of an eight-bit PCM-work into an analogue output voltage in accordance with the CCITT A-law, with a weighting network and a stepwise switched operational amplifier, with inputs for connection of each bit of said PCM-word with said weighting network and said amplifier via digital gates and low-impedance switches and with a control line for controlling the sign of said output voltage in accordance with the sign-bit of the PCM-word. The converter is characterized by connection to ground of both ends of the weighting network's resistor chain, by two resistors for the continuous resp. the switched input of each a predetermined current to the output line of the weighting network and by a switchable voltage divider at the output of the stepwise switched amplifier.

Abstract: A plurality of subscriber stations is connected to one or more PCM multiplex lines of a PCM switching network via a unidirectional loop and a transfer station. The subscriber stations are series connected to the loop on which addressed telegrams circulate originating and ending at the transfer station. The subscriber stations receive the telegrams addressed to them and exchange them for transmission to the transfer station. The transfer station transmits a time-slot received on the PCM line as an addressed telegram and vice-versa. For enhancing reliability all subscribers can be connected via a second loop and a second transfer station to one or more further PCM lines.

Abstract: A wireless paging receiver to be called up individually or as member of a group of receivers by a binary modulated carrier frequency call telegram. Each call telegram contains an address. Each individual address is composed by code words selected from a certain number of patterns. In a group call address one or more code words are replaced by a group call pattern, so that all receivers are called whose addresses contain the remaining code word patterns. For coding the address in the receiver only one connection must be positioned for each address code word. Messages can be transmitted with the call telegram and different call signals of different lengths generated. A parity check of the received call telegram is performed with little additional material.

Abstract: Circuitry having at least two stores for the periodical storage of instantaneous values of at least two similar stochastic signals, at least two comparison circuits for comparing during a comparison time interval the stored values with subsequently occurring values of the other signal and for the formation of two positive functions depending on the comparison results, a device for the temporal integration of the differences of the two functions, and a device for indicating the sign of the result of the integration thus providing a determination of the direction of the mutual temporal shift T of the two stochastic signals.

Abstract: In a digital telecommunication network containing bearer channels between switching nodes, the method of building-up a routing address consisting of routing words that are associated with the switching nodes and via which the transmission of information packets is effected in accordance with the routing address contained in each packet, and for their storage in the region of a called subscriber, dispatching a build-up packet from the first calling subscriber which contains the location-independent call number of the called second subscriber, each switching node retransmitting to other switching nodes connected to it at least the first of several successively received build-up packets having the same call number and whose routing address does not exceed a specific length and adding to each build-up packet retransmitted a routing word associated with the bearer channel connected to it and forming a part of the travel path of the build-up packet, the called subscriber designated by the call number or the switchi

Abstract: The invention relates to a method for limiting the number of build-up packets during the process of building-up a routing address for the subsequent transmission of address-coded packets, the addresses of these packets being this said routing address, from a first to a second subscriber of a digital telecommunication network. This network comprises a plurality of switching nodes, a plurality of subscribers, a plurality of bearer channels connecting each switching node with at least one other switching node and with no subscriber, or with one or more of said subscribers, a plurality of routing words individually assigned to the bearer channels and a plurality of call numbers individually assigned to the subscribers.

Abstract: A general digital message network for short address-coded telegrams having plural switching stations. In each switching station the outputs of the input stores are each connected to one of the inputs of a multiplexer. The inputs of the output stores are connected to the output of the multiplexer and the output stores are each connected to a comparator circuit with a fixed value store in which the routing word associated with the outgoing line of the output store is stored, in such a way that upon correspondence of the routing word in one of the fixed value stores with the routing word at a specific location of the address of the telegram in the associated output store, this telegram is transmittable onto the output line thereof.

Abstract: A plurality of subscriber stations and a plurality of switching points are connected in series in a loop circuit transmitting signals in one direction, parallel line sections disposed in parallel with the loop circuit are each connected with two switching points and each switching point contains a switch controlled by a failure detector and adapted for switching between a loop circuit section and a parallel line section. The transmission direction of the parallel line sections corresponds to the direction of the loop circuit; an incoming parallel line section which by-passes one or two immediately preceding switching points and an out-going parallel line section which by-passes one or two immediately succeeding switching points are connected to each switching point.

Abstract: A closed unidirectional transmission loop has plural stations coupled thereto in series for transmitting time multiplexed signals in the form of addressed byte groups. For transmitting a byte group, a station delays at the end of the byte group passing on the loop the following byte groups and introduces the byte group to be transmitted into the space resulting from the introduction of the delay. As soon as a byte group that is being or has been received by its addressee arrives at the station, this station removes the delay, thereby eliminating the byte group and thereafter can send the next byte group.

Abstract: A black and white facsimile communication system wherein the document to be transmitted is scanned line by line, the scanner signals are sampled to obtain pulse sequences having a constant number of pulses for every line. The pulse sequences are converted into codewords for redundancy reduction. The codewords are transmitted and, in the receiver, reconverted into pulse sequences which control reproduction. Before reproduction every pulse sequence obtained by reconversion is tested whether it contains the correct number of pulses. If that is not the case, the last reproduced line is reproduced again instead of the line received with an error.