Abstract: A magnetic tape recorder/reader including several magnetic heads (30-45) driven in a rotary movement at the periphery of an equatorial slot (4) of a cylindrical drum (1) on the surface of which runs a tape (7) wound helicoidally and a capacitive coupling device (20), the device being designed to transmit electrical signals between a part rotating around an axis connected to the heads and forming a rotor and a fixed part forming a stator, said device (20) including at least one coupling component (47-54, 73-80; 204; 220) comprising a mobile part (47a-54a, 73a-80a; 206; 222; 230, 232) and a fixed part (47b-54b, 73b-80b) connected respectively to the rotor and to the stator, characterized in that the mobile and fixed parts of the coupling component are made in the form of rings and/or segments of rings called coupling rings, respectively arranged in two mutually parallel planes (P.sub.1, P.sub.

Abstract: A device for remote metering, comprising a meter (4) for measuring a consumption, a transmission circuit for transmitting information relating to quantities consumed, and consisting essentially of a modulating circuit (5,6) and of a bifilar line (3), and a counter circuit for counting sets of information. The modulating circuit comprises a capacitive network (6) and at least one switch (5) which is actuated by the meter and which is capable of modifying the capacity of the capacitive network. The device further comprises a circuit (7,14) suitable for evaluating the value of the capacity of the transmission circuit, and thus for distinguishing two states of the modulating circuit and one state of a fault in the line. Such a device is, in particular, usable for the remote metering of a consumption of gas or of electricity.

Abstract: The present invention relates to synthesis of an analog waveform representative of digital input words but subject to band limiting. In a device for performing such a synthesis a plurality of samples, obtained from the input words by accessing them in memory at a sampling frequency are filtered by a programmable digital filter to yield a plurality of output words which may be fed to a digital to analog converter at a conversion frequency, the converter producing an analog output representative of the input words.

Abstract: A method and device for evaluating an angle A known by at least two trigonometric functions and capable of varying over a range greater than 360.degree..Two counter integers N.sub.0, N.sub.1 are stored and up-dated, each with respect to the other, as a function of even and odd indicator signals FC.sub.2, FS.sub.2.The value of the angle A, expressed in quarter turns, is given by the first or the second counter number as a function of the value of the even indicator signal FC.sub.2.

Abstract: A method of and apparatus for determining which if any phase of duplex supply lines wherein each phase w is assigned two conductors w1 and w2. The method and apparatus use an asymmetry value, for example a function of the relationship (output of 9) of the difference Iw1-Iw2 (output of 5) to the sum Iw1+Iw2 (output of 6) of the currents in the conductors w1 and w2. If the asymmetry level exceeds in absolute value a threshold level K(see 12 and 13), the conductor passing the current having the lowest amplitude is indicated as being sound.

Abstract: A band pass digital filter which may be straightforwardly implemented. Considering successive samples I the last of which is N and input samples XI and output samples YI, the filter, in one embodiment, conforms to the expression:Y.sub.N =2.sup.-K+J.(X.sub.N -X.sub.N-2)-C.sub.4.Y.sub.N-1 -Y.sub.N-2 +2.sup.-K.Y.sub.N-2where J and F are integers.

Abstract: The invention relates to a shift register structure and its control. The positioning and/or synchronization of data contained in this register for the purpose of serial operation are essentially obtained by acquisition of data on at least one auxiliary output SA1 of this register R. In particular the invention enables a programmable delay buffer register to be produced very simply.

Abstract: A device for detecting and localizing neutral particles such as X photons, gamma photons or neutrons is essentially constituted by a solid converter (2) disposed at a glancing incidence relative to the radication to be detected, together with networks of wires such as (3') disposed in the proximity of the converter. The device is applicable to industrial imaging.

Abstract: Method and apparatus for the regulation of a modulated signal transmitted from a transmitter (E) to a receiver (R) in a differential protection system for an electrical installation. The invention lies in the regulation of the frequency spectrum of the modulated received signal (SMR). The presence of a fault in the electrical installation in this spectrum of low frequency components is attributed to presence of noise bursts in transmission affecting the received signal (SMR).

Abstract: At transmission (10) each bit for transmission is coded as a function of its state by producing (12) a particular coding frequency combination, these being divided into two distinct bands spaced one from another and the coding combinations being chosen such that frequencies ranked in the same sequence place in these combinations do not occupy the same frequency band. A signal comprising the coding combination is injected to the network (N,P) and at reception (20), is applied to demodulators (22, 23), each assigned to one respective frequency band, to be correlated with locally generated signals (25, 26) which reproduce the coding combinations with a constant frequency shift, the bit state being determined (24) as a function of the correlation output.

Abstract: A method and device for supplying a sinusoidal output signal of controlled phase. First and second input signals, of different phase but derived from a common sinusoidal source, are multiplied by second and first sinusoidal reference signals, respectively. The reference signals are obtained by sampling the first and second input signals. The multiplied hybrid signals are applied to a difference amplifier to produce an output signal having a phase of predetermined value, independent of the instantaneous phase angles of the input signals.

Abstract: The connector comprises: a central shaft (7) at the periphery of which linear conductor elements are longitudinally disposed, at least in a zone of contact provided on the shaft; a group (22) of radially disposed resilient conductors having conductive ends bent substantially into conformity with a toroidal surface centred on and facing towards the shaft (7) at a certain level of the zone of contact; resilient toroidal couplings (27,28) centred on the shaft (7) and surrounding said ends; a clamp (22,29) for compressing said couplings radially so as to urge, at the time of said compression of the couplings, the conductive ends radially inwardly into pressure contact with the longitudinal conductor elements of the shaft. This connector forms part of a rotor carrying magnetic heads of apparatus (FIG. 2) for recording on and playing back magnetic tape.

Abstract: Method and device to supply, from a source of alternating voltage (5a or 5b), a thermal printing head (3) comprising a number of heater units (3a, 3b).The device comprises a means (6a to 6d) of obtaining a rectified voltage, a means (8) of detecting the points when the alternating voltage or the rectified voltage change to zero and to produce a detection signal, a means (9) of synchronizing, with this detection signal, the heating of particular heater units and a means (7a, 7b) to absorb current.

Abstract: A very high frequency harmonic generator utilizes a type III-V (e.g. GaAs) FET. An input signal is applied to the gate of the FET at a sufficient level to induce non-linear functioning of the FET. This causes an output signal to appear between the source and drain having frequency components of at least the tenth harmonic of the input signal. The device is particularly applicable to the generation of microwave signals.

Abstract: The present invention provides a simple apparatus for modifying at will the trajectory of heads in a rotating head magnetic recorder (for example, when the playback speed is changed) without introducing any active elements in the moving parts. Fixed electromagnets, controlled by a position sensor, control pendulum movements of the heads oscillating under centrifugal force due to their rotation.

Abstract: Apparatus for recording and reading information on a magnetic tape, comprising heads rotating in the median plane of a drum (38) against which the tape can pass over a helical path (11). Means are provided for modifying the pitch of the helical path (11) of the tape, such as two movable rollers (55, 56) disposed respectively downstream and upstream of the drum (38), separated by a fixed difference in height and adapted to move in such a manner as to vary the length of the portion of tape connecting them without varying said difference in height.

Abstract: Method and apparatus for determining, at a measurement point in a faulty conductor of electrical energy, a fault parameter such as the distance between the point of measurement and such fault or the direction of such fault. As a signal of a fault current, the device utilizes a signal I.sub.pa formed by a linear combination of a signal representative of homopolar current and a signal representative of an inverse current associated with a fault. The invention is particularly applicable in the case of networks having at the point of measurement an insensitivity to homopolar current or to inverse current.

Abstract: Tape drive apparatus having a drive roller 1 and pinch roller 2 including a idler roller 3 around which tape 4 passes. The pinch roller 2 which is rotatable about two normal axes (A2 and A4), is resiliently urged against the drive roller 1 and the idler roller 3, the two rollers being spaced apart from each other. This apparatus is particularly useful for magnetic tape cassettes, the pinch roller 2 being formed as either part of the cassette or as part of a tape recorder/player for using a cassette.

Abstract: A plurality of single-phase energy sensors each having a first input connected to a current converter and a second input connected to voltage converter supply pulses to a calculating device. The number of pulses over time represents the energy detected by the single-phase sensor. The calculating device is based on a microprocessor and comprises accumulators controlled by the pulses delivered by the energy sensors for supplying the active and reactive power measurements sought. In the case of a four-wire network, it is not necessary to use voltage transformers for the interphase network voltages, and the energy sensors supply pulses which represent the active and reactive energy of each phase.

Abstract: In a magnetic tape cassette having an elastic belt for maintaining the tension of the tape, a second, curved roller is provided between the belt and the floating roller which presses the belt against the tape reels. The two rollers are mounted on a common semi-restrained slidable support plate. The pressure exerted on the second curved roller is transferred to the floating roller by the plate, while the second curved roller, which is biconical, maintains the height of the belt even when the tape is repeatedly wound and rewound over a short section of its length.