Abstract: The interface of the invention comprises a power supply circuit (16) which is a symmetrical amplifier circuit, and a hybrid circuit (29) controlling the power supply circuit in DC and in AC. The hybrid includes a phase shifter circuit (44, 45) simulating long lines.Application: private telephony.

Abstract: A read/write memory cell comprises a first switch having one input which constitutes the data input-output of the cell and another input connected to a loop circuit comprises a first inverter, a second inverter and a second switch. The first and second switches are controlled in such a way that on a write operation the first is closed and the second open. In the absence of any write or read operation the first switch is open and the second switch is closed. On a read operation both switches are closed. A read/write memory of N words each of P bits is obtained by associating N.times.P cells of this kind in a matrix comprising N rows and P columns.

Abstract: A prediffused integrated circuit having rows of basic cells on a substrate. Each basic cell includes two MOS transistors connected in series through a common drain or source electrode, each transistor having a separate gate. All basic cells in a row are the same type while adjacent rows alternate between p-type and n-type.

Abstract: A decentralized arbitrator includes an individual elementary arbitrator and a level elementary arbitrator for each arbitration unit. Determination of the priority due to one unit, when no other unit claims priority, is accelerated by directing the request states of all units on the same level and on all other levels to the input of an AND gate, the output of which is connected to the bus-utilization enablement input of the relevant unit, through an OR gate and a D flip-flop.

Abstract: A ringing signal generator for a subscriber telephone set comprising a switch switching the input signal, followed by a phase shifter and two symmetrical amplifiers having a very high output impedance at rest. The lines are driven through isolating capacitors.

Abstract: A PCM time division exchange with decentralized processing having a central processing unit connected by means of a switching network to several racks, each rack has a message microcontroller and several port cards. The message microcontroller is responsible for the signal dialogue between the different ports and it exchanges telephone messages with the central processing unit.

Abstract: The telephone circuit of the invention comprises a transmission circuit short-circuited during decimal numbering by an active circuit when the handset is lifted or during the emission of a decimal numbering digit, the line current supplying, through a voltage stabilizing circuit and a voltage regulation circuit, the microprocessor controlling the telephone circuit.

Abstract: The decentralized arbitration device of the invention comprises an arbitration unit associated with each processing unit. This arbitration unit comprises an individual elementary arbitrator and a level elementary arbitrator. Their outputs are connected to a comparator which compares their output signals with the code of the unit considered, which code is supplied by a coding identification circuit. The individual priority request terminals of the units in the same level are connected together and the level priority request terminals of all the units are connected together.

Abstract: An arbiter cooperating with p.n processing units grouped into p levels each comprising n processing units. An elementary arbiter is assigned to each level, and a central arbiter attributes cyclically the priority to each level. The central arbiter comprises essentially a memory programmed for attributing a single priority to each level.

Abstract: A logic selection module for forming the interface between the two central units and eight selection circuits of an electronic time automatic telephone switchboard and which comprises means for selecting the calling central unit, means for connecting the thus selected central unit, means for decoding the address of one of the eight selection circuits to which the module is connected in the signal received from the thus selected central unit and means for transmitting the marking signals received from the central unit to the said circuit, whose address has been decoded.

Abstract: The telephone station has a first attenuator inserted in a transmission channel, and a second attenuator inserted in a reception channel. Each attenuator has a variable impedance mounted in shunt on the corresponding channel. A circuit controls the attenuators as a function of the relative levels of signals collected respectively from the transmission and reception channels. A bridge circuit introduces a difference between the levels of the signals collected respectively from the two channels. The bridge circuit includes a resistor bridge formed by two fixed resistors inserted in each channel upstream of the attenuator which is associated with said channel, and by a variable impedance which constitutes the attenuator. The common node of the two fixed resistors is the point of collection of the signal from each channel.

Abstract: The invention relates to a display screen horizontal scanning control protection device. The device comprises a switch making it possible to open or close the supply circuit of the scanning control circuit, said switch being activated with the aid of a signal supplied by an AND gate, whose state is a function of the level of the supply voltage of the central unit, which itself generates the horizontal scanning sync signal activating the scanning control circuit.Application to telematic terminals equipped with a cathode-ray tube screen.

Abstract: The system is constituted by a wired logic included in a signalling unit, which also has a microcomputer. This logic is connected on the one hand to the incoming and outgoing signalling junctions of a connection network and on the other to a programmed peripheral marking unit by means of which a central computer supplies correspondence data between an incoming junction channel and an outgoing junction channel.

Abstract: The switching device includes an array (1) with space-division switching by directional couplers without signal memorization, directional couplers (2.sub.1, . . . 2.sub.r), detectors (3.sub.1, . . . 3.sub.r) and receivers (4.sub.1, . . . 4.sub.r) connected to a processor which controls the switching of the couplers of the array (1) via an interface circuit (6). The processor reinserts in the output channels switching control signals and synchronization signals via converters (8.sub.1, . . . 8.sub.s) and couplers (7.sub.1, . . . 7.sub.s).

Abstract: The connecting device according to the present invention comprises for a two wire to four wire converter which connects the reception channel of a private network to the public network via an amplifier, whose symmetrical outputs are connected to the public network by capacitors, the gain loss due to these capacitors being compensated by a second amplifier. For the transmission channel a third amplifier has inputs connected to the public network by capacitors and an output connected to one input of a fourth amplifier, whose other input is connected by a phase shifting network to the reception channel.