Abstract: An actuating mechanism of a three-position switch, the switch comprising a main shaft supporting or actuating contacts and able to be moved selectively to three stable positions and a center crank which is pivotally mounted and can be actuated so as to take the three positions of the main shaft, the mechanism in addition having a mechanical system which produces a kinetic ratio between the angular movement of the center crank and that of the main shaft which increases when the center crank moves from the open position to the closed position, which results in the force transmitted to the electrical contacts increasing continuously as movement takes place from the open position to the closed position.

Abstract: A cabinet formed from a unitary open-faced cubicle structure having two lateral walls, an upper wall, a bottom wall, and a rear wall. A door closes the open face of the structure. The cabinet has at least one chimney along one lateral wall, the chimney extending from the front, open face to the rear wall of the cabinet. The chimney opens at both the rear wall of the structure and the front face of the structure. The opening at the front face is positioned to receive a lock carried by the door. Therefore, the lock is isolated from the interior of the cabinet, and the interior is protected from entry of dust and moisture. The cabinet also has a flashing system in the vicinity of its edges, which prevents entry of water into the interior of the cabinet. Additionally, the cabinet has edges in the vicinity of the door that provide additional pressure on seals within the door.

Abstract: An electronic trip device comprising, for each phase or neutral line, a rectifier bridge formed by four diodes which rectify the transformer current, a resistance for measuring the rectified current, and a circuit for detecting the sign or polarity of the measured current connected to one end of the transformer. A processing circuit calculates a value representative of the earth fault current by adding all the current values whose corresponding sign is positive and subtracting all the current values whose corresponding sign is negative. This current value is processed so as to bring about tripping when a threshold is exceeded for a preset time.

Abstract: Failure of one or more battery cells, for example of an inverter battery bank, is detected by monitoring the second derivative of the curve U(t) representative of the voltage U at the terminals of the battery in the course of discharge. If the second derivative is positive, this is significant of a failure.

Abstract: This neutron detector device includes a containment inside of which there is mounted a detector and which contains a neutral gas. The detector is formed by a fission type chamber comprising a cylindrical-shaped external electrode, coated with a lining of uranium in metal form, enriched as isotope 235, and a cylindrical-shaped internal electrode coaxial to the external electrode. The containment is of annular shape and arranges a cylindrical center space open at both ends to house a moderator to slow down the fast neutrons with great efficiency with respect to detection. The present invention provides an advantage of making it easy to replace the moderator. It is favorable to use cylindrical electrodes of large diameter thus increasing the sensitivity.

Abstract: The computing device comprises non-recursive, digital filters, with finite impulse response, computing, from samples taken over a period of the power system, for at least two distinct phases, two components with a phase difference of 90.degree. between them and representative of the quantity involved in the phase involved. A matrix computation using a two-dimensional rotation matrix enables the components with a 90.degree. phase difference of the inverse component to be deduced therefrom.

Abstract: A system for continuously monitoring electrical conduction of an AC power system comprises at least one measuring module connected between two conductors of the power system. A measuring cycle is divided into two periods. During the first period, the module measures a first DC voltage component, representative of the stray DC components, applied to its terminals. During the second period, the measuring module inputs a DC current component to the power system and measures a second DC component of the voltage applied to its terminals. The difference between the second and first components is used to detect a conduction fault, the line resistance upline from the measuring module being proportional to this difference. The first and second components are obtained by computing the mean value, weighted if necessary, of DC voltage samples measured during measuring periods of a duration lower than or equal to the first and second periods.

Abstract: A compact fail safe interface includes an astable multivibrator ring type oscillator that includes an odd number of inverting components. Power supply inputs of the inverting components of the oscillator constitute functional inputs to the interface. In the event that one of the inputs is not correctly supplied, the oscillator generates a continuous safe state output signal. The interface is particularly suited for use with voting modules designed to increase both the safety and the availability of an installation.

Abstract: The monitoring device comprises a measuring channel of the ground fault voltage, a measuring channel of the ground fault current, and a digital processing circuit whose role is to search for and indicate the presence of a ground fault. The processing circuit determines the fundamental parts of the ground fault current and voltage to compute the phase difference .phi. between the two parts and the cos .phi. value. The evolution of this phase difference is representative of a fault.

Abstract: The manufacturing process of a capacitor with a polypropylene dielectric film by introducing pre-cross-linking elements of the polypropylene at the time of manufacturing. When the capacitor is used, the electrical field and/or temperature generated trigger the cross-linking process of the polypropylene, delaying and slowing down the ageing phenomena, i.e. the decrease of the dielectric strength. The pre-cross-linking agent is a polyfunctional monomer to which an activation accelerator and/or a stabilizing agent can be added.

Abstract: A measuring assembly is formed by association of a current sensor with non-magnetic toroid and a supply transformer with magnetic circuit arranged around the toroid. The first secondary winding of the current sensor is located nearer the primary conductor than the second secondary winding of the supply transformer.

Abstract: The backup time of the battery is obtained by estimation, in iterative manner, of discharging of the battery during successive estimated time intervals. During each of the estimated time intervals, an estimated discharging current in terms of the actual discharge power, an estimated voltage, and an estimated state of charge are computed in accordance with a mathematical model equivalent to the battery. The backup time of the battery is equal to the sum of the estimated time intervals necessary for the estimated voltage to reach a preset threshold. The process enables ageing of the battery to be taken into account and an alarm to be provided when the lifetime of the battery becomes too short.

Abstract: A molded case circuit breaker with interchangeable trip units has on its front face a frame protruding out from the front panel of the circuit breaker, and surrounding the circuit breaker operating handle. The frame has a window in which the end of a bracket support is inserted fixedly secured to the trip unit, when the latter is in place. An inscription, notably of the rating of the trip unit, is borne by a face of the bracket support so as to be visible at all times, even when a front protection plate covers the trip unit.

Abstract: The communication circuit of the self-powered trip device is disabled by the trip device microprocessor when the values of the measured currents are lower than preset values. The microprocessor sends a bit, called the power saving bit, before disabling the communication circuit so as to inform a monitoring device connected to the trip device of the cause of the interruption of transmission from the trip device.

Abstract: A self-extinguishing expansion switch or circuit breaker, including an extinguishing chamber and an expansion chamber connected by a duct. The extinguishing chamber is positioned above the expansion chamber. An axially movable tube supports a movable arcing contact which is cooperable with a stationary arcing contact. The axially movable tube separates axially from a conducting tube supported by an operating rod such that the circuit breaker is in an isolated position beyond an open position.

Abstract: The electronic trip device comprises a device for selecting the faults which are to bring about locking of the circuit breaker contacts in the open position. When a fault in the power supply system protected by the circuit breaker leads to a trip, the trip device orders locking if this fault is one of the faults selected by the selection device.

Abstract: The operating mechanism of the four-pole circuit breaker comprises an auxiliary mechanism coupled to the main mechanism. The spring of the auxiliary mechanism exerts a torque on the bar, opposing the force of the contact springs when the circuit breaker completes its closing travel and when it is closed; the spring ceases to act on the bar when the circuit breaker has begun its opening travel and when it is open.

Abstract: An arc extinguishing chamber of a pole of an electrical circuit breaker having rotating arc device, the extinguishing chamber operating by self-extinguishing expansion, includes an elongated housing sealed off at both ends by end plates. Coaxially inside the housing there are disposed tubular contacts and a magnetic blowout coil. Along the length of the extinguishing zone defined by the separation distance between the contacts, there is located a sleeve positioned to leave a gap, which allows a top open area of the chamber and a bottom open area of the chamber, located on opposite sides of the extinguishing zone, to communicate. The gap allows the gases to flow between these two areas and fins arranged on a bottom portion of the chamber slow down rotation of the gases to direct them to the extinguishing zone.

Abstract: Inside a sealed enclosure (10) filled with sulphur hexafluoride there are housed main contacts (17,19) and an auxiliary circuit comprising two vacuum cartridges (20,21) electrically connected in series with each other and in parallel with the main contacts. The vacuum cartridges (20,21) are operated by a single mechanism to open and close simultaneously and serial connection enables the voltage withstand to be increased. The invention can be applied to medium or high voltage gas-insulated installations or substations.

Abstract: A circuit breaker assembly is equipped with a pre-tripping device comprising a fixed cam securedly united to a connecting base, which cooperates with a rocker and a transmission lever when the circuit breaker is drawn-in and drawn-out from the connecting base. The profile of the fixed cam is chosen to actuate the transmission lever and impose tripping of the circuit breaker, during draw-in or draw-out travel, whereas the transmission lever is in the inactive position after the circuit breaker is drawn-in or drawn-out, in which the latter can be opened or closed normally.