Abstract: A method and device are provided for the transmission of data. After organizing the data into words all having the same number of bits, tables are formed each comprising a plurality of words, the words of these tables are coded by means of an error correcting code, and the bits of each table are transmitted using an interleaving method, at a transmission rate sufficient so that, during the time of formation of the table of rank N, a number R of tables, of rank N, N-1, N-2, . . . , N-R are transmitted. The reverse operations are carried out at reception. This method makes it possible to tolerate interruptions in transmission having a relatively long duration, without introducing too great a delay between the source and the user circuit.

Abstract: A double interaction switch has a case in which a single block of contactors is controlled by two levers; namely, one monostable lever and one bistable lever. The bistable lever may be locked in one of its two stable positions. When the bistable lever is so locked, the monostable lever may be moved, and actuation of the bistable lever thereafter causes it to return to its unlocked position. When the monostable lever comes back to its rest position, with the bistable lever initially locked, the bistable lever comes back to its rest position. The bistable lever is lockable by means of a rod which may pivot under the action of a labyrinth, provided on the lever. The switch is suitable for use with "hands free" telephone receiver sets.

Abstract: An oscillator is provided whose oscillation frequency is substantially proportional to the intensity of the ambient magnetic field, and which is used for measuring said magnetic field, and comprising a magnetic resonance magnetrometric probe for detecting a signal at the frequency of said magnetic resonance in response more particularly to a low frequency excitation signal and means for generating said low frequency excitation signal in response to the detected signal, said generation means comprising a loop for locking the phase of said low frequency excitation signal to the phase of said detected signal, and initialization means so that said low frequency excitation signal sweeps a range of frequencies when said loop is not locked.

Abstract: A nuclear magnetic resonance magnetometer is provided comprising two semi-coils which pick up precessional signals of the nuclear spins of two samples. A capacitor of a battery of capacitors forms a resonating circuit with the two semi-coils. The signal at the terminals of the capacitor is amplified in a differential amplifier, phase-shifted in a phase-shifter introducing a constant phase-shift of 90.degree., and reinjected into the semi-coils through a potentiometer. The frequency of the oscillations is measured by a frequency meter. A circuit controls the connection of the capacitors of the battery is response to the valve of the frequency measured so as to maintain the parasite phase-shifts between signals picked up and reinjected signals less than a threshold.

Abstract: Frequency measurement involves anti-foldover filtering (1) of an analog signal whose frequency i.e. to be measured, followed by sampling of the filtered analog signal and analog-digital conversion of the samples, then digital band-pass filtering (3) on a slaved basis. Associated calculation (4-7) utilizes a linear regression having a single coefficient a for the linear relation between successive digitized samples (2) and to estimate the coefficient a for approximation of the frequency to be measured. The invention is particularly applicable to signals from a probe having nuclear magnetic resonance used in measuring intensity of the terrestrial magnetic field disturbed by metallic masses.

Abstract: A device is provided for measuring the earth's magnetic field disturbed by anomalies, including a probe in which are mounted, aligned and harmonized with each other, a nuclear magnetic resonance measuring probe associated with its oscillation electronics and the means for compensating for the anomalies due to the carrier: a triaxial magnetometer and a two axis gyrometer. The device can be mounted on land vehicles, ships and aircrafts.