Abstract: The interface card fixedly secured to the circuit breaker supplies information representative of the circuit breaker type and rating to a standard removable trip device. It comprises for example resistances designed to be connected in parallel to a resistance of a divider bridge defining in the trip device the instantaneous tripping threshold, modifying this threshold automatically according to the circuit breaker type and rating. The interface card can also supply the trip device with information representative of the rated current flowing in the primary winding of the current transformers fixedly secured to the circuit breaker.

Abstract: A certain number of high bits of each sample (12 bits) supplied by an analog-to-digital converter is used as the address of a comparison zone of a RAM associated with the microprocessor of the device. In this comparison zone the result of comparison of this sample with a predetermined number of thresholds has previously been recorded. The sample (12 bits) and associated comparison result (4 bits) are stored in a storage zone of the RAM for subsequent processing by the microprocessor. This simultaneous acquisition of a sample and of the prerecorded result of comparison of this sample with the thresholds minimizes the time devoted by the microprocessor to data acquisition.

Abstract: A movable contact bridge of a molded case limiting circuit breaker is supported by a bar by a system of springs enabling opening with electrodynamic repulsion. The contact bridge cooperates with stationary contacts rigidly secured to current input conductors in the shape of half-loops. An anvil is adjoined to the rear of the stationary contacts to increase the closing impact effect of the contact bridge and prevent contact resistance dispersions. The anvil is made of ferromagnetic material increase the magnetic field for blowout of the arc to the extinguishing chambers.

Abstract: The contact bridge of a molded case circuit breaker is rotatably mounted in a bar by two springs arranged symmetrically from the rotation axis. Each spring is, on the one hand, anchored to the contact bridge, and, on the other hand, anchored to a rod housed in a notch of the bar. The same springs provide contact pressure and slowing-down of opening of the contact bridge at the end of repulsion travel by electrodynamic effect. The contact bridge bears on its edge cam surfaces which, at the end of opening travel, engage the anchoring rods to move them in the notches in the elongation direction of the tension springs. The energy of the contact bridge is thus taken up and stored in the springs causing slowing-down of the contact bridge. The profile of the cams can be chosen to enable reclosing of the contact bridge, this reclosing naturally being delayed by the slowing-down effect at the end of travel. The cam profile can also ensure latching of the contact bridge in the open position.

Abstract: The processing circuit of the insulation monitor comprises a microprocessor receiving on a first input a signal representative of the DC component, or the component of preset frequency different from the frequency of the mains system to be monitored, of the voltage applied to the insulation monitor terminals. The microprocessor receives on a second input a signal obtained by making the difference between a measured voltage representative of said voltage component and a preset threshold value and by multiplying this difference by a multiplication coefficient. When the measured voltage is greater than the threshold value, the microprocessor uses the signal applied to the second input so as to improve the precision in the higher voltage range.

Abstract: An operating for a circuit breaker including a pivoting handle for controlling opening and closing of the circuit breaker and resetting of the latch after tripping. The handle bears a resetting roller which cooperates with a cam surface of the latch, which surface has a first cam section and a second cam section separated by a slope change point. The second section corresponds to the reset position and the slope of this section is chosen in such a way as to obtain a stable reset position of the handle.

Abstract: A modular low voltage multipole circuit breaker, including a plurality of identical single-pole breaking units each including a parallelipipedic insulating box having two opposite parallel large side faces and two opposite parallel small side faces, two terminals located at respective opposite parallel small side faces, a stationary contact electrically connected to one of the terminals, a movable contact cooperable between a first position contacting the stationary contact and a second position separated from the stationary contact and a molded case for housing the single-pole breaking units. The molded case has two opposite parallel side walls having the same thickness, the single-pole breaking units being sequentially arranged and parallel to each other and parallel to the side walls such that adjacent single-pole breaking units are spaced apart a distance equal to twice the thickness of the side walls, the single-pole breaking units being spaced apart at a constant pitch.

Abstract: An electrical breaking device including a movable contact assembly. The movable contact assembly includes a support cage and upper and lower contact fingers pivotally mounted thereto on respective upper and lower transverse spindles. The upper and lower contact fingers are parallel to each other and each include a head having a movable contact at a first end thereof, and a second end opposite the first end which is connected to a flexible conductor. The lower and upper contact fingers are cooperable with a stationary contact assembly. The lower transverse spindle is positioned to be closer to the first end of the lower contact finger than to its second end. In contrast, the upper transverse spindle is positioned to be closer to the second end of the upper contact finger than to its first end. The longitudinal spacing between the upper end contact spindles yield an attraction force which counter-balances repulsion forces acting on the movable contacts through which a current flows.

Abstract: A reference AC signal having a frequency of about 4-10 Hz is injected into a line of a DC electrical network for performing insulation measuring in a processing unit. The AC signal is measured in a mixed bridge having a first resistive dividing bridge connected in parallel with a second capacitive dividing bridge between the line and the ground. The intermediate output points of the first and second bridges are joined together and connected in an input of the processing unit. The impedance and the dividing ratio of the two bridges cause the DC voltage measured at said input to be low in relation to the value of the AC voltage measured at the output of said mixed bridge.

Abstract: Two solid copper pieces are assembled by welding without filler metal. The pieces both have a projection which are placed facing and in contact with one another, before the pieces to be assembled are placed on the welding press. Welding is performed by passing a very high intensity current for a short period of about one tenth of a second under very high pressure. The welding operation prevents any annealing of the copper.

Abstract: A low voltage multipole circuit breaker having a double housing, each pole including a single-pole breaking unit having a parallelepipedic plastic box having two extended side faces. Contacts are further provided and are associated with an extinguishing chamber housed within the single-pole breaking unit. Several units are mounted side by side in the parallelepipedic box to form a multipole circuit breaker.

Abstract: A vacuum cartridge of a hybrid circuit breaker comprises an end-plate having a groove for housing an annular coil external to the cartridge and electrically connected in series with the contacts of the cartridge. The coil is located facing the arcing contacts and is rigidly held by the groove.

Abstract: An electromagnetic actuator comprises a coil associated with a magnetic circuit having a first series of polar parts to drive a rotor, and a second series of polar parts cooperating with a pivoting blade. A return spring causes movement of the blade to a separated position. A latch is rendered active to lock the blade in the separated position during rotation of the rotor, and inactive to unlock the blade enabling its electromagnetic attraction against the polar face, and stopping of the rotor. The actuator has an operating mode either as motor or as electromagnet depending on the position of the blade.

Abstract: A remote transmission device for the automation of an electrical power distribution system includes a pilot and slave mechanism of communication by on-line carrier currents using capacitive coupling of the lines of the power system as transmission support for the exchange of information and order to a plurality of breaking devices. Depending on the priority code of modems in the system, on the level of the received signal, and on the open or closed position of certain breaking devices, the transmission device breaks down automatically into several disunited subsystems, each containing a source substation to which a communication zone is assigned, whose boundaries in normal operating conditions are formed by open line switches. In emergency situations, the boundaries of the communication zones are modified by a coupling circuit which can be in a first by-pass state or in a second dual coupling state.

Abstract: A device connects an external electrical power supply source to an aircraft on the ground to temporarily replace its auxiliary power units. During the overlap period of the two switches used in the aircraft to achieve this transfer, an impedance, preferably a resistance much greater than the internal impedance of the external source is connected in series on the external line. As soon as switching to the external source has been completed, measurement of a sudden drop in the external voltage brings about closing of a static switch which short-circuits the resistance.

Abstract: An isolation monitor is electrically connected between the earth and an isolated neutral of a transformer which supplies AC electrical power to the main distribution network. In order to measure and to locate an isolation fault occurring somewhere on the feeders, each feeder is equipped with a toroid current measuring transformer, and comprises further a secondary winding connected to a processing locator performing synchronous demodulation. Two first and second transmission lines are provided between the isolation monitor and the locator. The first synchronous line transmits synchronization pluses from the monitor to the locator, and the second line transmits to the locator the demodulated values of the input voltage furnished by the monitor.

Abstract: An auxiliary generator supplies a sinusoidal voltage of fixed amplitude adjusted in phase to the mains supply voltage. A comparator, followed by a threshold circuit and a bistable switch, enables a static contactor to be opened almost instantaneously when the difference between the voltages of the mains supply and of the generator exceeds a certain preset value. Power is then supplied by an auxiliary back-up power supply.

Abstract: The device measures the current intensity in a conductor by FARADAY effect in a monomode optic fiber. It comprises a separator-polarizer formed for example by two coplanar half-disks of polarizing foil, whose polarization directions form a required angle, 90.degree. or 45.degree.. Photodiodes formed by a two-quadrant photodetector in the shape of a disk of the same diameter as that formed by the separator-polarizer, are located behind from the separator-polarizer. The photodiodes are connected to an electronic unit.

Abstract: A keylock system comprising a lock and a key for opening and closing the lock, the key having an outer radial retaining stub protruding radially outward, the lock including a base plate for attachment to a surface of an enclosure, a cylinder rotatably mounted within the base plate, the cylinder having a first end adapted to engage the key, and a second end protruding from the base plate, the cylinder being rotatable between open and closed positions, and retaining sleeve threaded onto the cylinder. The retaining sleeve comprises a plurality of retaining fingers engaged with the cylinder to a low rotation thereof, an immobilizing finger for engagement with the base plate to prevent rotation of the retaining sleeve, and a top annular surface defining an opening having a reduced diameter which allows passage of the key therethrough.

Abstract: A vacuum electrical switch comprises a coil arranged in the metal base plate of the cartridge. The metal base plate constitutes a current input to the contact, this input having a radial conducting path and a path forming a spiral, electrically connected in parallel. In order to enhance the current flow in the spiral, which forms an axial magnetic blowout coil, the base plate has ripples or a slit which lengthen the radial conducting path.