Abstract: An optical transformer designed to equip a grounded metal-clad installation, wherein the transformer includes a disk which is disposed transversely to the axis of the cladding and which is provided with openings via which the conductors pass, optical fibers being disposed at the periphery of said openings and being connected to an associated optical interface placed outside the cladding.

Abstract: A circuit-breaker including at least one insulating interrupting chamber inside which there are contacts and a blast nozzle. The insulating interrupting chamber is placed on an insulating support containing a drive rod. The circuit-breaker further includes a first terminal and a second terminal. The circuit-breaker has at lest one fluorescent or scintillating optical fiber disposed inside the support and constituting a symmetrical loop around the drive rod. Each end of the fiber is connected to a photodiode equipped with an amplifier. Light propagated in the interrupting chamber, as a result of arcing, reaches the optical fiber loop via a light passage within a terminal of the interrupting chamber remote from the arcing zone within the interrupting chamber.

Abstract: A hybrid current limiter comprising a first winding of non-superconducting conductive material having a large number of turns and electrically connected in series with a superconductoring coil of low self-inductance and placed in a cryostat, and a second winding of non-superconducting conductive material having a small number of turns, said second winding being closely coupled with said first winding in such a manner as to obtain low overall inductance, the second winding being connected in parallel with the series circuit constituted by the first winding and the superconducting coil.

Abstract: A safety device for an electrical apparatus comprising an enclosure filled with gas under pressure, the safety device comprising first means for detecting the appearance of an arc inside the enclosure, and second means controlled by the first means to establish a path for the gas through the enclosure when the first means has detected an arc for a given length of time.

Abstract: A feedback system control device includes an adder producing a control signal from a feed forward signal and a correction signal. A system which processes the control signal drives the feedback system, which produces an output signal. A feed forward circuit, e.g., a four-pole network, receives the input signal and produces the feed forward signal. An error amplifier in the corrector processes the difference between the input signal and the output signal to produce an error signal. A corrector produces the correction signal from an input signal and this error signal. Two processors in the corrector each receive the error signal and produce respective modification signals between which there is a relative phase shift. An adder sums the modification signals to produce the correction signal.

Abstract: Device for detecting the quenching of part a superconducting element comprising two identical superconducting conductors electrically connected in parallel is provided with means (104, 105, 109, 110) of detecting a difference in intensity or phase between the currents flowing in the conductors. An application to a superconducting current limiter is described.

Abstract: The present invention relates to a capacitive sensor comprising two concentric capacitors having a common electrode, namely a high tension capacitor and an auxiliary capacitor, the sensor including two screens separating the two electrodes of the high tension capacitor, and these two screens leaving a gap between each other of constant size. The invention is applicable to metalclad stations.

Abstract: A circuit for measuring voltages in a three-phase installation, in particular an installation of the metalclad type, the circuit including for each of the phase conductors: a capacitive divider including a first capacitor connected firstly to said conductor and secondly to a second capacitor (C1, C2, C3) connected to ground, the circuit being characterized in that the voltage (v1, v2, v3) of each of the second capacitors (C'1, C'2, C'3) of the dividers is respectively applied firstly to the input of an inverter (I1, I2, I3) and secondly via a first resistance (R1, R2, R3) to the negative input of an operation amplifier (A1, A2, A3) which is also connected via second and third resistances (R21, R12, R13, and R31, R32, R23).

Abstract: The invention relates to a system using Rogowski coils to measure the phase currents in a three-phase installation. Each coil (1, 2, 3) is connected firstly to a corresponding operational amplifier (10, 20, 30) connected as an integrator, and secondly to a corresponding inverter (100, 200, 300) whose output is connected to the inputs of the integrating amplifiers of the other two phases. With appropriately selected resistance values, mutual interference effects may be cancelled. The system is suitable for measuring phase currents in an installation housed in a cabinet or cubicle.

Abstract: The optical fiber interferometer system is used either in a gyroscope or else for measuring electrical current by the Faraday effect. It includes an optical board (100) which is connected to the two ends of a monomode optical fiber (200) constituting an interferometer ring, said optical board including a photodetector (103) which is colinear with the light source which is coupled by both its front and its rear faces. The two counter-propagating beams travelling round the interferometer ring have their relative phase difference modulated by phase modulation and their light power modulated by amplitude modulation. An electronics board (300) generates these modulations and, from the photodetector signal (103), it extracts a component at the lower beat frequency between said two modulation frequencies, thereby making it possible to measure the relative phase difference between the two beams.

Abstract: The method is intended for use in a step-down high tension current measuring apparatus using the Faraday effect and including a Sagnac interferometer having an optical loop constituted by a fiber (47) surrounding the high tension conductor (11) conveying the alternating current to be measured and terminating at an integrated optical circuit (43) which delivers an output light beam to an electronic circuit with the optical power of the light beam having a component in its spectrum at a frequency which is a sinusoidal function of the phase difference generated by the Faraday effect, with the coefficient of proportionality being referred to as a scale factor. The method consists in periodically updating the scale factor used for interpreting measurements on the basis of D.C.

Abstract: The voltage divider comprises a capacitor column (11) for dropping nearly all of the high voltage and a base capacitance (10) connected in series therewith so that a small voltage appears there across. Said discharge circuit comprises a diode rectifier bridge (15, 16, 17, 18) connected by its AC terminals in parallel with the base capacitance, and two identical windings (20, 21, 22, 23) connected in parallel respectively with two of the diodes (15, 16) of the bridge, both of said winding-shunted diodes being connected to the same one of the AC terminals of the diode bridge.

Abstract: Said circuit includes a generator (7) at ground potential and delivering power at a high-frequency which is transmitted to the electronic apparatus (2) to be powered via two high-frequency transformers (10, 8) one of which is at ground potential and the other of which is at the potential of the electronic apparatus (2). Said transformers are galvanically isolated from each other by two capacitors (4 and 9).