Abstract: The very fast circuit breaker assisted by semiconductor electronics. A piston 21 slides in an insulating housing 20 and along a center shaft 22. The piston 21 has of an exciting winding 25 and a magnetic yoke 26, which by cooperating with an armature 28, join the piston 21 to the center shaft 22, a shoulder of which renders possible the holding of a repulsion disk 34. The repulsion disk carries the moving contacts 35 and 36, which cooperate with the stationary contacts 37 and 38, when the piston is in its high position under the effect of a locking spring 24. Upon the injection of a current into the repulsion coil 45, the repulsion disk 34 is violently repulsed in the downward direction, while jumping the electromagnetic lock established between the magnetic yoke 26 and the armature 28. An admission of compressed air through an orifice 27 permits the descent of the piston 21.

Abstract: A method and an apparatus for measuring the position of regulating rods in a nuclear reactor through the measure of a voltage appearing across the terminals of an induction coil fed by a constant current AC supply, each regulating rod being interlocked with a control rod able to move along the longitudinal axis of said coil. The regulating rods are grouped into a plurality of groups in such a way that the said regulating rods are randomly distributed throughout the reactor so that no two regulating rods in the same group are located close to one another. The thus formed groups of regulating rods are energized in sequence, and the voltage appearing across the terminals of the coils of each group is measured during a time interval corresponding to the feeding time interval of that group. The voltage is then memorized for a time interval corresponding to the non-feeding time period of the group.

Abstract: A method and an apparatus for measuring the position of a magnetic rod moving along the longitudinal axis of an induction coil. The induction coil is fed by means of a constant current AC supply and the resulting voltage appearing across the terminals of the induction coil is measured. Then, the reactive component value of that voltage is determined which is representative of the position occupied by the magnetic rod in the coil.