Abstract: An arrangement for connecting a personal computer (1) to a telephone network (2) via a digital exchange, in particular a private exchange (13), and via a telephone set (3) or subscriber terminal suitable for processing telephone signalling and enabling digital voice and data signals to be transferred simultaneously, the telephone set or subscriber terminal being controlled by an internal processor (14) of a controlling logic circuit (9) and including a data transmission (4B) for connection to a computer apparatus such as a computer. The coupler (4) is integrated in the telephone set and is connected to the controlling logic circuit (9) of the telephone set, which diverts the telephone signalling transmitted to the controlling logic circuit of the telephone towards an external access (1A1 or 1A2) to the bus of the personal computer, and which selectively replaces the telephone signalling which the telephone would normally transmit to the exchange by corresponding signalling produced by the personal computer.

Abstract: A synchronizing system for a private digital exchange (1) comprising a logic control unit (4) and specialized interfaces (9, 8) whereby the exchange is connected firstly to a plurality of subscriber terminals (2) via SO accesses, and secondly to a telecommunications network (3) via TO base accesses. The exchange includes a time base (6) which associates a fixed frequency local oscillator (7) with a phase locked loop (32). The system includes clock switching means suitable for imposing the first clock signals to come from the network (3) via an active one of the TO base accesses and the associated interface (8) on the phase locked loop (32) of the time base (6) as soon as said first clock signals come close in phase to the substitute clock signals provided by the time base (6) in the absence of said first signals from the network.

Abstract: The safety interlock for a cover of a housing in a telephone apparatus provides electrical safety for the user by requiring the apparatus to be disconnected from a telephone line before the cover of the housing can be opened. The apparatus is connected to the telephone line by means of a two-part pluggable connector, with one of the parts being a receptacle fixed in the case of the apparatus. The safety interlock comprises a flap (8) which slides inside the case (1, 2) of the apparatus over the opening (5) giving access to the telephone line connector receptacle, with the flap sliding between a closed position in which it disengages the opening (5) while holding the cover (8) of the housing closed, and an open position in which it obstructs the opening (5) while allowing the cover (3) of the housing to be opened.

Abstract: The mechanical safety assembly for a telephone set having a housing with a cover including a sliding lock for closing the cover (7). The lock includes an operating head (13) external to the body (1) of the telephone set or terminal. The head fits flush with the wall of the body (1) when in the closed position and leaving only smooth surface visible, one of said surfaces (23) being pierced with a hooking aperture (24) which is accessible by a tip (25) of a paperclip or ballpoint pen.

Abstract: A time-division switching system, in particular a multiservice key telephone or PABX system, is controlled by programmed management logic and synchronized by a timebase for selective on-demand exchange of information between terminations to which telecommunications terminals are connected either directly or through links to other, identical or at least compatible switching systems. The system includes programmed system management logic based on an optionally duplicated processor with directly addressable memory which stores all command operations, in particular those for switching information exchanged by means of the terminations which are connected in parallel to a port of the processor by a bus-type time-division multiplex link.

Abstract: A remote monitoring system for remotely monitoring, by telephone, at least one apparatus of an installation (1), acting through a telephone network (2) having lines to which the installation and at least one distant terminal device (3) are connected for remote monitoring purposes, the system being characterized in that it comprises, local to the installation, a premises controller (4) organized about a microprocessor control circuit (18) and connected firstly to units (23, 24 25) of the apparatus to be monitored in the installation, and secondly to a directory terminal (5) of a type suitable for automatically detecting and dialing telephone calls (12, 13) in order to be put into communication with the terminal device (3) through the telephone network, said terminal device being compatible with the selected directory terminal (5) so as to enable them to be put into communication with each other manually and/or automatically from either end via the telephone lines (L1, L2) respectively connecting the terminal d

Abstract: A remote power-feeding and protection system for equipment connected by two transformers to a four-wire transmission link.The remote power-feeding and protection system and the remote power-feeding extractor protection device are intended for equipment connected by two transformers to a transmission link with two pairs of wires ensuring remote power-feeding of the fed equipment.Each transformer is connected to the two wires of one pair by two identical windings serially-connected between these two wires through a capacitor. The two pairs of wires constitute a phantom feed circuit, the two wires of a given pair being connected to the same terminal of a D.C. generator. The extraction and protection device comprises two rectifier bridges each separately connected by their inputs to a pair of wires and interconnected by their outputs in order to provide remote power feeding.

Abstract: Telephone subscriber connection system based on a ditital time-division switch. System of connecting telephone subscribers whose devices (2) are connected to junctors (6, 7) of a digital time-division switch (1) controlled by a central processor (5). Each junctor is identically connected to the switching network (4) of the switch by the same number of channels of a shared time-division multiplex link (LM0), all information concerning a junctor passing on these channels between the junctor and either another junctor or the central processor. The latter has direct access to the switching memory (17) of the switching network enabling it to read or write there directly. Requests addressed to the central processor (5) from the devices (2) connected to a junctor (6) are directly transmitted by this means to said central processor.

Abstract: A method of routing calls for a network of digital time-switched exchanges (A, B, C, D, E, F, D) interconnected by groups (18 to 28) of PCM time multiplex trunks, with each group ingterconnecting two exchanges. Each exchange establishes a utilization cost for each of the groups connected thereto. This cost is based on the busy fraction of the least busy trunk in the group of trunks under consideration and it is transmitted to all of the exchanges in the network in order to enable them to determine least cost paths for the calls that they are requested to set up.

Abstract: A charge-removing device intended to eliminate electrostatic charge from a thin dielectric strip, and in particular a rolled dielectric film. The device comprises at least two electrically conductive rolls (4,5) forming electrodes which are subjected to a potential difference by a low frequency high tension source. These rolls are parallel and come into transverse contact at the same time with respective faces of a thin strip dielectric (1) passing therebetween. The invention is applicable, in particular, to electrostatic type printers.

Abstract: The protection device in accordance with the invention is connected in series with the line. It comprises either a circuit (1) for providing protection against voltage surges, or else a filter (2) for providing protection against radio frequencies, or else both said circuit and said filter. It protects terminal equipment (telephone set, data terminal, fascimile machine, etc.) against disturbances both in differential mode and in common mode. The device is mounted in a protection connector which may either be of the wall socket type or else of the removable adapter type for plugging into a conventional wall socket, and in either case the terminal equipment has a plug which plugs into a corresponding socket of the protection connector.

Abstract: Message signaling device for a telephone installation having analog stations and station equipped for this purpose. The invention has as its objects a signaling device by light means for a telephone installation whose subscribers are equipped with analog stations and the stations equipped for this purpose. Each telephone station (4) concerned is equipped in parallel, on the one hand, with a message lamp (59) in series with a resistor (60), on the other hand, with a capacitor (61), coming out of the rectifier bridge (51) of the station. The message signaling is achieved by action of the control unit (3) of the telephone exchange equipment on the injector (36) of ringing signals assigned to the station, so as to cause it to transmit rhythmic signals which differ from the rhythmic ringing signals by the shorter period of the transmission phases of the signal and which make possible the lighting of the lamp.

Abstract: The invention relates to an interface circuit for connecting a digital equipment (2) for sending and receiving data to a time multiplex link (3). The connection interface circuit is provided with a bit send terminal (3E1) and a bit receive terminal (3R1) for connection to the corresponding wires (3E, 3R) of a time multiplex link (3) in parallel with other interface circuits (1 or 8) of equipments for transmitting and receiving digital data (2) or speech signals (4). The interface circuit includes a synchronization arrangement (12) enabling it to be connected to the multiplex link (3) in a manner identical to that provided for the interface circuit (8) of the transmitter/receiver equipments for speech signals (4) and to adapt itself automatically to the bit rate capabilities offered by the multiplex link.

Abstract: An electrostatic print head for creating a latent image on a dielectric recording medium (1) in order to enable said image to be subsequently transferred to a final medium (generally ordinary paper) after development by inking. The print head comprises a conventional multitude of electrodes (E) and associated conterelectrodes (CE) disposed in parallel rows for progressively building up an electrostatic latent image on the moving dielectric medium (1), and includes an additional rotary coupling electrode (EC) which is raised to a direct potential whose average voltage is of the same polarity as the high voltage control pulses applied to the counterelectrodes, which pulses are themselves of opposite polarity to the pulses applied to said electrodes. The coupling electrodes (EC) is pressed against the recording dielectric medium level with the electrodes and the counterelectrodes, and against the opposite side of the medium relative to said electrodes and counterelectrodes.

Abstract: An electrostatic printer uses a dielectric film (10) as an intermediate recording medium for an electrostatic latent image which is to be printed on a final recording medium (1) such as sheets of paper. The latent image is first developed by inking, and the inked image is then fixed on the final medium by pressure using a transfer unit having pressure rolls (11A, 11B) between which the intermediate medium and the final medium are passed while pressed against each other. Two portions of the same dielectric film are pressed against opposite faces of the final medium as it passes between the pressure rolls of the transfer unit with each portion being suitable for receiving an electrostatic latent image from a corresponding write head (8) with images being inked by corresponding inking devices (9), and with each inking device being associated with a corresponding different one of the rolls of the transfer unit.

Abstract: The invention relates to electrostatic print heads enabling an electrostatic latent image to be progressively built up on a moving medium (18) which may be constituted by special paper or by some other material, by discharging ions using a set of aligned electrodes (20) and a counterelectrode (1) disposed opposite said electrodes on the other side of the moving medium (18). The counterelectrode (1) is constituted by a cylindrical or semi-cylindrical resistive layer (7) covering connection conductors (C.sub.1 to C.sub.n+1) which are constituted by parallel rings or ring sectors sharing a common axis with the resistive layer and having cylindrical or semi-cylindrical resistive portions extending therebetween. The rings or ring sectors are individually connected to outlets from an electronic selective switching circuit (CEC) which is at least partially housed within the concave portion of said counterelectrode (1).

Abstract: Telephone sets associated with terminal units such as modems or telecopiers generally need to be used without the handset being lifted off the gravity switch. Such telephone sets also tend to include electronic circuitry which is powered by DC derived from the telephone line via a diode bridge (11) to protect against reversals of line polarity. The line is initially looped by a user-operated switch (T) having contacts (t1) connected in parallel with the gravity switch looping contacts (cc1), and thus on the line or AC side of the bridge (11). Once adequate power is supplied to a controlling microprocessor (5), it causes a relay (RE) to close line-holding contacts (re1) in parallel with the looping contacts already mentioned (t1, cc1). The loop is released by means of a release transistor (15) connected in a common return wire on the DC side of the bridge (11).

Abstract: A plurality of PCM signal samples destined for the same telephone set are transmitted over different respective time slots of a time divided transmission link serving the telephone set. Each sample destined for the telephone set is decoded during a single time slot, the resulting decoded pulses are added together once per frame, and the sum transmitted to the telephone set for a period which is equal to the duration of one frame. The summing unit is coupled firstly to the output of a digital-to-analog converter and secondly to the input of a hold circuit. Its main components are an operational amplifier and capacitors which are suitably connected by transistors.

Abstract: A device for increasing the operational security of a duplicated clock which comprises first and second clocks comprises in each clock a selector circuit with inputs connected to a filter and signal shaping circuit of each clock. Each selector circuit comprises two processing circuits and an output circuit which implements the following logic equation:w=(q1+q2).multidot. w1+(q 1+ q2).multidot.w2in which:w is a clock signal from the selector circuit,w1 and w2 are the reconstituted clock signals produced by the first and second clocks, respectively.q1 and q1 are the direct and complemented output signals of the bistable of the first processing circuit, andq2 and q2 are the direct and complemented output signals of the bistable of the second processing circuit.