Abstract: Coefficient signals are generated for a transverse filter which receives data signals assuming W different amplitude values as input signals, with N successive input signals being stored in a serial-in-parallel-out (SIPO) storage arrangement having N storage cells. According to the input signals stored in the storage cells of the SIPO storage arrangement, predetermined filter signal coefficients possible for the W possible amplitude values individually are added and W corresponding partial sum signals made available. The partial sum signals are each multiplied by a factor corresponding to the particular amplitude value and subsequently added to form a sum signal. At least some of the product signals are multiplied by an additional correction signal coefficient assigned to the particular amplitude value. The additional product signals resulting therefrom are included in the formation of the sum signal.

Abstract: A programmable ring signal generator includes a source of a user control signal. A controlled clock signal generator produces one of a set of respective clock signals responsive to the user control signal. A switched capacitor filter is coupled to the clock signal generator for converting the clock signals to an analog sine-wave. Finally, a power amplifier, coupled to the sine-wave converter, produces the ring signal.

Abstract: To the switching node belongs at least one coupling element which has n input lines and n output lines optionally connectable to them via a space switch. To each of the input lines a buffer store is assigned in which k data packets are storable and which has m.ltoreq.k output terminals via which m data packets are simultaneously suppliable to the space switch having m.times.n input terminals and n output terminals. The storage addresses, under which the data packets to be routed are stored in the individual stores, are stored in accordance with the address signals contained in the data packets and stored in queue buffer stores assigned to the output lines. The queue buffer stores are cyclically accessible by a central control device for making available storage addresses. On the basis of storage addresses made available in such manner the central control device, on the one hand, controls the setting of the space switch and, on the other hand, the output of data packets from the buffer stores.

Abstract: An apparatus for separating dc current and ac current signal portions of a composite signal. The apparatus has a main current path for carrying the composite signal. This path splits into a dc current path and into two dc blocked ac current paths. At the node a virtual ground potential for the ac current signal portions is generated with the aid of an inverting amplifier with negative feedback located in one of the ac current paths. Thus, only the dc current portions flow over the dc current path. In a preferred embodiment, the dc blocking is implemented by a capacitor in each ac current path, and the inverting amplifier is an operational amplifier, whose non-inverting input is at ground potential, whose inverting input is connected with the respective capacitor and whose output is connected both with the inverting input via an ohmic negative feedback resistor and with an impedance in the other ac current path.

Abstract: A telecommunication system is provided consisting of a plurality of functional units each one producing a status signal. A maintenance processor is coupled to each of the functional units and receives the status signals. This processor produces signals representative of the status of the system. A remote alarm reporting unit is coupled to the processor and generates optically isolated alarm signals corresponding to the status representative signals generated by the processor.

Abstract: In a telecommunications exchange system, consisting of a central section comprising a central switching network and a central coordination processor, and consisting of line trunk groups which are connected to the switching network via allocatable connection paths and which each comprise a subsidiary switching network and a subsidiary control unit, between the coordination processor on the one hand and each of the subsidiary control units on the other hand, a control channel exists via which the former at all times has access to each of the latter. With the start-up of an entire exchange system or only of individual line trunk groups, the coordination processor loads the subsidiary control units with items of switching orientated program information and with items of connection state data individually assigned to the individual subsidiary switching network terminals, which can consist of subscriber terminals and connection line terminals.

Abstract: A circuit for implementing a connection of an operational amplifier, and for achieving the switchable sensitivity of the same, as well as the in-and-out switchable filter elements, which results in a low cost, universally applicable line circuit interconnect circuit.

Abstract: A thyristor protected against breakover firing is disclosed which has a region which, in comparison to the remaining semiconductor body, has a lower breakdown voltage. This region is provided with an auxiliary electrode and is separated from the remaining semiconductor body by a trench. Upon onset of the avalanche breakdown in the blocking direction, a voltage greater by 0.5 V, compared to the first emitter electrode, can build up at the auxiliary electrode without the thyristor firing. The auxiliary electrode is connected via a resistor with the first emitter electrode of the thyristor. In addition, between the auxiliary electrode and the control electrode a breakover element is interconnected which conducts at a given voltage drop across the resistor and initiates the firing process of the thyristor.

Abstract: An apparatus for separating dc current and ac current signal portions of a composite signal. The apparatus has a main current path for carrying the composite signal. This path splits into a dc current path and into two dc blocked ac current paths. At the node a virtual ground potential for the ac current signal portions is generated with the aid of an inverting amplifier with negative feedback located in one of the ac current paths. Thus, only the dc current portions flow over the dc current path. In a preferred embodiment, the dc blocking is implemented by a capacitor in each ac current path, and the inverting amplifier is an operational amplifier, whose non-inverting input is at ground potential, whose inverting input is connected with the respective capacitor and whose output is connected both with the inverting input via an ohmic negative feedback resistor and with an impedance in the other ac current path.

Abstract: A digital interface between at least two subscriber line interface circuits and a processing unit is described. The interface is configured in the form of a parallel interface. The level of an input/output register and of a control register is allocated, as needed, to the connections of the processing unit. These connections can be operated selectively as inputs or outputs. They can also be operated in two modes, depending upon which type of subscriber line interface circuit (SLIC) is connected. The connections of the last-mentioned units are partially operable as inputs or outputs and partially operable only as inputs but in the input case, selectively for various types of input signals.

Abstract: An expander system for pulse signals with enhanced output power level is disclosed. The expander system, which comprises an expander filter and subsequently connected amplifier means, is provided with a supplementary 180 degree phase modulator connected in front of the expander filter. The phase modulator is switched on and off by a control signal delivered from a control stage in such a manner that, during the duration of a pulse signal, the phase modulator produces at least two phase shifts of approximately 180 degrees.

Abstract: This invention covers a phase shifter-equalizer circuit including a purely resistive impedance, a purely reactive impedance, at least one of which adjustable, and a phase inverter device, which permit to adjust in a continuous way the phase between the output current and the input current, while maintaining the amplitude of the output current constant and substantially equal to the amplitude of the imput current versus phase and group delay variations between the two currents. Furthermore, continuous phase adjustment is achieved by adjusting one only parameter of the circuit.

Abstract: Before each actual resistance measurement, a first preliminary measurement with short-circuited measuring circuit and a second preliminary measurement with the measuring circuit operating at no-load are carried out. From the measured values of the preliminary measurement steps, a weighting factor is calculated, by which, subsequently, the difference between the actual measured value and the short-circuit value is multiplied to form the actual measurement results.

Abstract: A digital interface of an integrated subscriber line interface circuit is provided. The interface serves for the connection of a signal processor unit. Individual connections are used as signal inputs in signal entry operation of the interface, and as signal outputs in signal transmission operation. Other connections are used as signal inputs in both operating mode, but receive different signals in each operating mode. One group of connections includes two registers with respective associated decoders to enable switching from one to the other, so that the number of operating instructions that can be represented by means of binary signal value combinations applied to the connections is doubled.

Abstract: In power switches, conductive coupling of the control signal inputs to the power switching stage, and to the load to be switched, can result in impairment of control function. Moveover these power switches known in the art, have the disadvantage that the drive circuit and power switching stage must lie at the same potential. An improved self protecting power switch includes a first drive unit and a second drive circuit that are connected together via a pulse transformer. The first drive unit generates successive pulse trains in response to a control signal. A second drive unit regenerates square wave signals for the control of the power switching stage.

Abstract: A circuit arrangement for a module in the line-connection section of a digital time-multiplex telecommunication network is disclosed. The module contains, among other things, a transverse filter to perform a two-wire/four-wire conversion and is connected through a transformer to the wires of a subscriber line. In order to compensate for phase distortions caused by reflection of signals from the transformer back to the module, the corresponding signals coming from the module are subjected to an equal and opposite phase pre-distortion. This optimizes the hybrid circuit attenuation.

Abstract: A method for measuring line parameters of subscriber lines of a telecommunication system in which end devices, exhibiting a capacitance, are connected to two wires of the subscriber lines is disclosed. The line parameters measured include the capacitances between each of the line wires and ground, the capacitance between the line wires, the leakage resistances between each of the line wires and ground, and the insulating resistance between the line wires. This task is accomplished by performing the following steps while the end device is connected to the subscriber lines. These steps are performed in three measuring configurations sequentially: first one of the two wires of the subscriber line is grounded and the measurement is performed in connection with the other, then the other one of the two wires is grounded and the measurement is performed in connection with the first, and then both wires of the subscriber line are connected together and the measurement is performed on the pair.

Abstract: An operational amplifier of the folded-cascode type with: push-pull output terminals; a differential-input transistors; a load impedance in the form of a cascode current source coupled to the differential-input, and a dynamic common-mode negative feedback. A current source transistor in the cascode current source is incorporated into the dynamic common-mode negative feedback.

Abstract: Two harmonic mixers arranged in parallel are connected to a first signal frequency gate and to a second local frequency gate by means of a single radiofrequency hybrid circuit in quadrature or by means of respective hybrid circuits of which one in quadrature and centered on the signal frequency and the other in phase, quadrature or opposition of phase and centered on the local frequency. Another intermediate frequency hybrid circuit in quadrature connects the two mixers to a third intermediate frequency gate and to a fourth gate closable on a termination. In this manner there is obtained a harmonic frequency conversion with image suppression.

Abstract: A pulse shaper forms multi-level signals with staircase-shaped level transitions. The formation of these staircase-shaped level transitions takes place through charge exchange between a plurality of connected, component charge-forming charging capacitors and a summing capacitor adding the component charges.