Abstract: A fault current circuit breaker has a summary current transformer whose secondary coil is connected to a voltage-independent energy storage circuit. A monostable or bistable transformer relay is actuated by an impulse by way of this energy storage circuit when a fault current flows to earth in the protected installation. When the relay contact is made, an electromagnetic lock trigger is actuated by the energizing current received from the mains supply, which triggers the switch lock of the FC switch. After this, the bistable transformer relay is returned to its initial position, either mechanically by way of an appropriate coupling with the switch lock, or electrically by way of a time delay or switch circuit, whereby the relay contact opens and the FC switch is again ready for switching on.

Abstract: An X-ray cable has a plurality of elements arranged concentrically relative to one another and including from inside toward outside at least one inner conductor, an inner conducting sleeve, a high voltage isolation, an outer conducting sleeve, a screen and a casing. The inner conductor is composed of one or several wires with a thickness between 0.1 and 0.6 mm. At least one of the wires is composed of ferromagnetic material with high permeability at frequencies over 1 MHz, and a direct current resistance of the inner conductor lies under 20 .OMEGA./m, so that without the use of damping members with a frequency above 1 MHz strongly increasing damping of occurring transient over voltages is provided.

Abstract: The electro-optical overhead wire is made from a plurality of circular cross-sectioned strand elements and consists of a core and a plurality of wire layers surrounding the core radially. The wire layers include at least one layer of chiefly electrically conducting wires and at least one other layer of predominantly high tensile strength wires. At least one of the wire layers of the high tensile strength wire also contains at least two strand elements arranged symmetrically around the core and each consisting of a high quality steel tube with an outer diameter of 2.5 mm containing at least 12 light wave guides. Alternatively or in addition, the electro-optical overhead wire is made up of a core and a first wire layer immediately surrounding the core and a second wire layer immediately surrounding the first wire layer, while the core contains a high quality steel tube with a five mm diameter containing 12, 18 or 24 bundles of light wave guides containing two light wave guides in each bundle.

Abstract: A safety connection device for connecting a high rupture capacity fuse link to a switching device and includes at least one connecting element having one opening receiving a guide carrying a cable from the switching device and another opening which receives the fuse link, and a contact spring and a contact bracket connected to each other and also connected to the fuse link and to the end of the cable inserted into the connecting element, respectively. The diameter of the opening receiving the fuse link is substantially greater than that of the fuse link.

Abstract: A light waveguide sensor for small pulling or pressing forces comprises a primarily coated light waveguide, a coil wound on the light waveguide and composed of an element having a diameter which is smaller than a diameter of the primarily coated light waveguide, a casing surrounding the primarily coated light waveguide and the coil and composed of a fiber reinforced synthetic plastic material with longitudinally extending, pulling resistant fibers embedded in a synthetic plastic matrix, the coil being composed of a plurality of coils arranged in cross-lay relative to one another on the light waveguide and each having a pitch length greater than 2.2 times the diameter of the primarily coated light waveguide.

Abstract: A measuring device with a light wave conductor-bending sensor for monitoring bridge structures comprises a light emitter and a light receiver, a multi-mode light wave conductor arranged to extend along a structural part and having two ends connected with the light emitter and the light receiver, respectively, an elongated plate having a lower side arranged to be placed on and connected with the structural part and also having an upper side provided with a longitudinal groove, two sliding rails arranged in the longitudinal groove and having outer ends fixed to the plate and inner ends spaced from one another to form an intermediate space and movable relative to the plate. The light wave conductor is fixed with one of the sliding rails, then extends through the intermediate space and forms a freely movable curve, and then exztends along and is fixed to the other of the movable rails.

Abstract: To enable a continuous measurement of damping of a light beam in light wave conductor (LWC)-sensor which is accessible at one end only, a measuring light beam emitted by a transmitter is guided through a light wave conductor into a beam divider in which a measuring partial light beam is guided in the same direction as the transmitted beam to a measuring LWC-sensor. At the free end of the sensor the measuring partial light beam is totally reflected to propagate in reverse direction back against the beam divider where it is deflected by 90.degree. and guided into a light receiving and measuring unit. The other partial light beam is employed either for the temperature compensation or for the compensation of the power output of the light transmitter or of sensitivity of the light receiver.

Abstract: To measure exactly minute elongations, for example on airplanes or bridge structures by means of a light wave conductor-phase sensor, the measuring beams of polarized light at the output of the sensor is divided by means of a beam divider into three partial light beams. The first partial light beam is directly received by a first light receiver; the second light beam is transmitted through a quarter wavelength plate and an analyzer to the second light receiver; and a third partial light beam is transmitted through an analyzer to the third light receiver. The electrical output signals from the light receivers carry information about extreme refraction values of the measuring light beam and are supplied to an electronic evaluation circuit.

Abstract: A device for measuring minute elongations of a light wave conductor is constructed as a light wave conductor-type sensing unit assembled of a series connection of a polarizer, a light coupler, a single polarization preserving, doubly refracting monomode light wave conductor enclosed in an elliptical sheathing and an analyzer. A light beam emitted from a laser diode is coupled via a light wave conducting correction cable to the polarizer and upon passage through the sensing unit is coupled via the light wave conducting connection cable to an optoelectric receiver and the electrical signals are evaluated in an electronic circuit. Changes in phase difference of the exiting light wave resulting from the minute changes in length of the light wave conductor are evaluated and scaled as geometric length units.

Abstract: A light wave conductor-sensor for tension, comprises a primary coated light wave conducting element, at least one coil wound on the primary light wave conducting element and forming together with the latter a sensor core, and a compound including longitudinally extending tension-proof fibers embedded in a synthetic plastic matrix, the compound forming a casing for the sensor core.

Abstract: A pressure-resistent locking mechanism for locking a door of a switch cell accommodating a switching device includes two pivotable locking bars positioned in hollows formed by U-shaped door edges and U-shaped portions of the wall of the switch cell at a hinge side of the door and a closing side of the door. The locking bars are pivoted between a locked position and a released position by pivoting levers against the forces of respective springs. The springs always urge the locking bars to the rest position.

Abstract: A pressure-resistant locking mechanism for locking a door of a switch cell accommodating a switching device includes two pivotable locking bars positioned in hollows formed by U-shaped door edges and U-shaped portions of the wall of the switch cell at a hinge side of the door and a closing side of the door. The locking bars are pivoted between a locked position and a released position by pivoting levers against the forces of respective springs. The springs always urge the locking bars to the rest position.

Abstract: A high tensile wire of a fiber-reinforced synthetic resin encloses an axially arranged light guide in the form of an optical fibers connectable to a light testing instrument. The light guide is enclosed in an intermediate sleeve of a heterogeneous synthetic material which is mechanically firmly connected both to the light guide and to the inner surface of the outer sleeve. In the preferred embodiment, the wire is used as a reinforcing span wire in concrete component parts and the attenuation of the light passing through the light guide indicates tensile strength, bending strength or breakage of the wire in the concrete.

Abstract: In an arc quenching device a quenching chamber filled with sulfur hexafluoride is provided with a plurality of superimposed overlapping ascending quenching plates having openings defining arc inlets. A movable contact cooperating with a stationary contact is insertable via the arc inlets into the quenching chamber.

Abstract: In order to upgrade input signals for further processing, one or more of the input signals is split up by a decimating technique into spectral component signals which are processed according to the desired purpose and recombined by means of an interpolation technique into an output signal. In this manner a digital filtering device can be selectively employed for achieving an arbitrary combination of simultaneous filtering, signal improvement, echo or feedback compensation, or signal masking of the input signals.

Abstract: An arrangement for mounting single-pole load-disconnecting switches in a middle voltage net includes a plurality of conventional, individually switchable load-disconnecting switches mounted on a single common base frame enclosed with a common housing. All the switches are arranged on individually rotatable hubs positioned on a common central shaft journalled in the base frame. Each hub establishes the connection between the associated load-connecting switch and a respective drive. Each switch is additionally provided with a support which carries a high voltage-high efficiency safety device.

Abstract: An HRC-fuse as an insulating body surrounding a main fusible conductor and an auxiliary fusible conductor connected to a spring biased impact pin. A conductive cap serving as a terminal for the fusible conductors is arranged on the insulating body and is provided with an outlet opening opposite the impact pin. A tripping hollow pin or sleeve coaxially surrounds at least a part of the impact pin and passes through the outlet opening. A bimetal release pawl is arranged in the one cap parallel to the pin and being electrically connected to the fusible conductors. The pawl engages a rest on the tripping sleeve to counteract a biasing spring. The impact pin and the tripping sleeve are triggered independently one from the other either by a short-circuit current melting the auxiliary conductor, or by an overload which heats up the bimetal release and triggers the sleeve. Both the tripping sleeve and the impact pin act on a load interruptor arranged opposite the outlet opening.

Abstract: A method of and a circuit for determining current criteria in a subscriber's loop of a telephone system are described. Two constant-current sources are symmetrically connected to two wires of the loop and are controlled by an adjustable reference voltage source. Voltage signals on the voltage source are evaluated in a detecting circuit to determine the actuation of a ground button on the subscriber's set or the occurrence of a ground short-circuit. A testing device is connectable to the subscriber's loop to simulate various conditions of the subscriber's set.

Abstract: A method of energizing a subscriber's circuit in a telephone system having two separate constant-current sources arranged symmetrically to the subscriber's station is disclosed. Current flowing through the two lines of the circuit is measured by a shunt, and differences between the line currents are compensated by a regulating device which applies such reference voltages to respective current sources as to supply a maximum permissible current in each line. If this maximum value is exceeded, then the regulating device automatically turns off, and a reduced reference voltage is applied to the current sources so as to return to the maximum permissible value of the curent.

Abstract: An arrangement for coupling the ends of optical waveguides includes a housing including at least one first passage for receiving the optical waveguide ends, a second passage for accommodating a plurality of pressing bodies, and at least one slot which extends along an arcuate course between the first and second passages and separates a clamping portion situated between the passages from the remainder of the housing which is constructed as a unitary body. The partial separation of the clamping portion from the remainder of the housing body permits it to resiliently yield to the pressure exerted by the pressing bodies, and thus to clamp the waveguide end in the first passage. A plurality of the first passages may be provided in the housing body around the second passage, each connected with the second passage by an arcuate slot. Another slot may surround the first passage at a distance therefrom.