Abstract: A gas insulated current transformer wherein the metal tank having the inductive unit therein is mounted on the hollow insulating bushing and preloaded with spring pressure so that when the insulating gas within the bushing and the container reaches a predetermined and maximum safe limit the excess build up of gas pressure is allowed to escape between the otherwise sealed contact between the container and the bushing.

Abstract: A toroidal coil is wound around a donut-shaped ferrite core through which passes one or more conductors for detecting a high current pulse within the conductors. An interface block includes a generally circular recessed upper portion for receiving the toroidal coil/ferrite core combination and further includes a pair of aligned, spaced slots extending between the upper and lower surfaces and within the recessed upper portion of the block. Each of the conductors is in the form of a strip-like metal conductor and is disposed within and along the length of a respective slot in the interface block. The upper end of each strip-like conductor is adapted for mounting to an upper portion of the interface block and coupling to a respective first lead by means of a first mounting screw. Similarly, the lower end of each strip-like conductor is adapted for mounting to a lower portion of the interface block and coupling to a respective second lead by means of a second mounting screw.

Abstract: A current transformer has a hollow tube made from an electrical conductor which is bent at its center so as to form a loop which functions as a primary winding and two parallel straight portions at the ends of the tube which function as leads for the primary winding. The tube has a longitudinally-extending fluid-carrying passageway for a dielectric fluid formed at its center. Both ends of the tube are open and communicate with the inside of a reservoir for a dielectric fluid. A longitudinally-extending electrically-insulating member is inserted into the fluid-carrying passageway of one of the straight portions of the tube so as to decrease the cross-sectional area of the passageway in that portion and increase its resistance to flow. The increase in flow resistance produces a temperature difference within the tube, promoting circulation of the dielectric fluid by convection.

Abstract: A combined high voltage current and voltage transformer of head-type construction with a column of insulating material carrying the top housing whereby the active parts of the current transformer and above the same the active parts of the voltage transformer are arranged within the top housing. A simple manufacture of the top housing and a good seal with as few as possible lead-outs to be sealed off inside of the top housing is made possible by the construction of this invention. At the same time, the primary conductor of the current transformer as also the secondary system of the current transformer and the active parts of the voltage transformer are to be assemblable in a simple manner. This is achieved in that the primary conductor of the current transformer is constructed U-shaped whose base extends at least approximately concentrically through the ring of the secondary system of the current transformer.

Abstract: A current detection device has an annular dielectric substrate with a thin (e.g., less than one skin depth at maximum frequency) resistive foil laid down on the substrate outer surface and extending completely thereabout. Annular metal rims are affixed to the substrate edges respectively contacting the metal foil or film. A conductive strip of appropriate dimensions is received onto the outer edges of the metal rims and extends about the complete circumference of the rims. A resistive material is used to secure the conductive strip to the edges of the rims so that the entire resistance of the strip and resistance material exceeds that of the sensing metal foil to prevent shorting out of the foil.

Abstract: An inductive current measuring sensor is provided comprising several coils connected electrically in series and disposed in a polygonal contour, so as to surround the conductor on which it is desired to measure the current. Each coil comprises windings disposed on an insulating bobbin and connection elements. The bobbins are disposed on the face of a printed circuit having a central recess through which the conductor may pass. The printed circuit carries conducting tracks interconnecting the fixing points of the connection elements together and to external connection members.

Abstract: A high-voltage current transformer of the head design with a column made of insulating material which supports the head housing. The primary lead is approximately U-shaped, whereby only its horizontal base passes through the central opening of secondary system and at least one of its two legs passes downwardly through a sealing plate in an insulating-medium-tight fashion to outside the space delimited by insulating column, and is contactable from below. The other of the two legs passes through sealing plate in the case of a switchable primary lead likewise downward in an insulating-medium-tight fashion and is directly contactable or in the case of a non-switchable primary is electrically connected to the sealing plate without any holes therethrough. The head housing, designed as hood, also completely encloses primary lead and secondary system from above and is fastened in an insulating-medium-tight fasion to sealing plate.

Abstract: A common neutral bus is formed in a lower frame extension of a large three-phase generator by disposing three sets of neutral current transformers within the lower frame extension and interconnecting the three phases downstream of the neutral current transformers to form an internal neutral bus. The neutral bus is connected to an external neutral transformer through a neutral terminal of small size and low cost. Clamshell clamps are provided in the internal neutral bus for isolating the neutral ends of the generator winding for test purposes. Rigid support of the current transformers and a hollow copper tube passing therethrough permits use of light and low-cost hollow copper tubing in place of the relatively substantial and expensive neutral terminals conventionally required.

Abstract: The neutral excitation and differential current transformers of a ground fault circuit breaker are arranged for automated assembly onto the signal processor circuit board to complete the signal processor module prior to insertion within the ground fault circuit breaker housing. Electrical interconnection between the transformers is made by a unitary conducting strap having means therein for receiving the circuit neutral conductor. The completely assembled signal processor module is connected with the circuit breaker components by means of a single wire.

Abstract: The current to be measured (I) within a conductor (1), is branched into two conductors (3, 4) of the same conductor material, which have a resistance differing relatively little from one another and at opposite winding direction form the primary winding of an active current transducer. The secondary current (i) is determined by the resistance ratio of the two individual conductors (3, 4). Through mechanical, and therewith thermal contact between the two individual conductors (3, 4), their resistance-ratio is also maintained at high temperature coefficients and at higher conductor temperatures.

Abstract: A sensing current transformer having a single turn primary winding for ground fault circuit interrupters and breakers utilizes a conductive post extending through the transformer metallic enclosure in combination with the conductive path across the metallic closure as the current sensing path. A four turn primary winding is provided by four metallic staples, each having one leg extending through the transformer aperture, for establishing four independent current sensing paths.

Abstract: Non-magnetic sensor having a ring-shaped core (10), through which a primary conductor (12) runs and which supports a secondary winding (14). A magnetic shield (18) encloses the core (10), whereas a non-magnetic conducting shield (22) is inserted between the conductor (12) and the core (10) with the winding (14). The sensor is applicable to medium and high voltage installations.

Abstract: A current sensing transformer useful for sensing overload current with static trip units is fabricated from an inexpensive array of transformer core laminations and a conventional secondary transformer winding. The transformer primary strap is arranged about the secondary winding for improved flux transfer.

Abstract: The current transformer for instruments for measuring electric currents includes a magnetic core that has two cores and an inductive current divider with three parallel current paths. The current dividers form, together with cores, two current transformer stages whose magnetic fluxes mutually cancel one another. In a current transformer for AC currents having a DC component, the ratio of the ohmic resistances of the individual current paths is in direct relation to their transformation ratio.

Abstract: A current transformer characterized by a terminal bushing extending from a tank with a pair of spaced conductors extending through the bushing and into the tank and with the portions of the conductors in the tank being enclosed within tubular means. The assembly of the conductors, bushing, and tubular means being clamped together by resilient (spring) means for holding the conductors in tension and the bushing and tubular means in compression. The transformer also embodies two separate oil systems.

Abstract: A ground fault circuit interrupter interconnect arrangement provides wireless connection with line and neutral main current terminals by insertion through an aperture in the interrupter magnetic sensor module to form a magnetic sensor plug-in subassembly. The electronics components and trip solenoid are mounted to the interrupter printed wire board. The magnetic sensor subassembly is plugged into the printed wire board for interconnection with the electronics components. This allows the interrupter to be assembled in a completely automated process.

Abstract: A pickup coil assembly comprises a pancake-shaped coil mounted in a plastic form having a pair of parallel support posts therethrough. The form is positioned in a plastic housing having a central aperture in one wall formed by cut away jaw portions for gripping a conductor inserted therethrough. A back wall of the housing includes a co-axial aperture of larger dimension to permit free passage of the conductor.

Abstract: A package for matching the characteristic impedance of a transmission line to the impedance of a pulsed semiconductor laser diode so that short duration pulses of light can be produced with a fast repetition rate. The package has a toroidal transformer in a cavity of a main body, with a multiturn primary connected to a transmission line. The laser diode is mounted at the edge of a known sandwich between two thin metal plates separated by an insulating layer. A spacer and metal cover cap are placed over the sandwich, and a screw passing through holes of all the parts is threaded into the main body. The screw passing through the transformer core forms a one-turn secondary. Not only does this allow the matching of the characteristic impedance, but also provides heat sinking for the diode. Assembly with a screw makes the unit easy to fabricate, and to replace the laser diode sandwich.

Abstract: The non-linear alternating current transducer includes a current transformer core (14, 50 or 80) comprising a yoke (14, 50 or 80) for receiving a line conductor (20 or 110) and a secondary winding (22 or 86). The yoke (14, 50 or 80) has an air gap (19, 56 or 101-105) configured to provide a non-linear magnetic circuit response for changes in current through the line conductor (20 or 110). The non-linear magnetic circuit response provides a logarithmic voltage output across the secondary winding (22 or 86). The current transformer (12) is used in a control circuit (10) for sensing, monitoring and interrupting current in the line conductor (20 or 110) such that a trip coil is energized to open the circuit whenever current is sensed above a predetermined current. Also, the logarithmic response provides for high gain at low currents and low gain at high currents to that a very uniform percentage-of-reading accuracy is obtained with a meter operating off of the secondary winding.

Abstract: A current transformer for very high tension units. The transformer has an insulating through bushing and an annular metal chamber both filled with compressed gas, a primary circuit with an input conductor which enters the chamber via the through bushing and an output conductor which leaves the chamber via the through bushing coaxially to the first conductor, and at least two magnetic circuits each having a secondary winding, wherein the current transformer has an electric side connection at the lower portion (21) of the metal chamber (11) and wherein the magnetic circuits (14, 15) are disposed on either side of said side connection.

Abstract: A low voltage circuit breaker with a current sensing unit having a magnetic circuit with three branches, the secondary winding being mounted on the intermediate branch and the primary winding being formed by a conductor selectively passing through one or two of the openings provided between the secondary winding and the outer branches. The circuit breaker comprises an instantaneous electromagnetic trip mechanism and a static long time and short time delay trip unit, the latter unit being governed by a signal attenuated by a rating selection device.

Abstract: A mounting device is disclosed which provides mechanical support and electrical insulation for a current transformer used in monitoring radio frequency signals in the neutral lead of a dynamoelectric machine. By encapsulating the current transformer in a rigid insulative apparatus with a central conductor passing therethrough, the transformer can be placed proximate the neutral bus of the dynamoelectric machine to avoid attenuation of the radio frequency signals.

Abstract: A ground fault indicator for a multi-phase power distribution system includes a split-core magnetic pole assembly having a gap within which is developed a magnetic flux representative of the vector sum of the currents in the individual phase conductors of the system. A magnetic reed switch positioned within the gap responds to the summation current in the gap to trip an indicating circuit in a remotely mounted indicating module in the event of a ground fault.

Abstract: A measuring transformer for use with high-voltage switch-gear of a type which employs metal encapsulation. The transformer is retained between flanges at a joint of the metal encapsulation and includes a sealing and insulating spacing means. The latter forms a ring-shaped cavity with the flanges and seals such cavity from the interior of the metal encapsulation. In the ring-shaped cavity is disposed at least one iron core having a secondary winding placed thereon, the latter core together with the inner conductor of the high-voltage switch-gear forming a current transformer.

Abstract: A zero-phase current transformer for use as a leakage current detecting element in a leakage current interrupter in which two magnetic materials of different permeabilities are provided so as to eliminate a range where the leakage current interrupter is inoperable without lowering its ability to distinguish noise components. The different magnetic materials may be provided as a single core constructed by mixing the materials of different permeabilities. Otherwise, the materials can be provided as annually-shaped magnetic pieces stacked one on top of the other. Still further, the materials of different magnetic permeability may be provided as bands of materials interwound to form alternating layers or one of the materials may be provided as at least a portion of a protective case.

Abstract: The invention relates to a current transformer for a high-tension installation, said transformer including a primary winding, a secondary winding and a magnetic circuit, said primary winding including a primary turn suspended coaxial inner and outer conductors in an insulation chamber which contains a dielectric fluid. The secondary winding (28) and the magnetic circuit (27) are disposed around the primary turn (6) on the outside of the chamber. Electrical continuity of the insulation chamber past an insulating seal (24) therein is provided by a jumper (29) which passes round the outside of the secondary winding and the magnetic circuit. The invention applies in particular to very high tension installations.

Abstract: The invention relates to a combined current and voltage converter for metal-enclosed high-voltage installations with compressed-gas filling. In order to be able to avoid any passages for the connecting leads through the housing (1, 2), the electrode of the capacitive voltage converter part consists of an intermediate element (3) inserted into the housing in an insulated and gas pressure-tight manner. The intermediate element (3) has on its outside a layer of insulating material (9) and on top of this a metal layer (10). The whole (3, 9, 10) forms a support body for current converter cores (11) surrounded by secondary windings. The low-voltage capacity between the intermediate element (3) and the metal layer (10) is fed to an electronic measuring amplifier (14) via a screened measuring cable (12/12a). The current converter cores (11) are protected mechanically by a sheath tube (16), the latter simultaneously conducting housing currents. FIG. 1.

Abstract: In an induction heating apparatus, direct sensing of the high frequency high power current flowing in the tank circuit to load the induction coils, is obtained with a coil current measuring transformer comprising one of the power current busses leading to the induction coil and a secondary winding of many ampere-turns wound around said one bus. The bus is given a half-loop shape to accommodate the secondary winding. The secondary winding is made of a magnetic core wound with many turns of Litz wire. Cooling tubes are cemented outside the wound secondary with conductive cement to form a heat sink with a circulation of cooling medium through the tube. The cement is divided in two parts separated by gaps to prevent circulation of induced currents. A cooling tube is installed between the core and wound wire to provide an internal heat sink.

Abstract: A current transformer is encapsulated in an injection molded layer of insulating material. The current transformer includes a secondary terminal assembly having individual terminals mounted on a terminal board. The terminal board is formed of a material that softens within the normal processing temperature range of the encapsulating material and forms an amalgamation therewith without a distinct interface between the terminal board and the encapsulating material which thereby provides a fluid-tight seal around the terminal assembly. The individual terminals have an intermediate shoulder disposed adjacent the top surface of the terminal board to prevent the molding material from covering the terminal assembly during the injection molding operation and, further, to provide a sealing surface for the molding material around the terminal assembly. A shorting bar is rotatably mounted between the terminals and rotates between a closed position shorting the terminals and an open non-shorting position.

Abstract: A solid state trip circuit is disclosed which uses a shunt path saturable transformer comprised of a current transformer having a relatively high resistance shunt which serves to apply input voltage to the transformer primary winding. The larger the input current the higher the voltage drop across the shunt and the more quickly the transformer iron will become saturated. The saturation time during each half cycle then produces a measure of the current flow in the primary line. The output of the secondary winding of the transformer as well as a direct but resistive connection from the input circuit lines are applied to a solid state trip circuit which operates a circuit breaker trip latch. Energy for tripping at lower overload current is derived directly from the applied voltage from the line. At high overload conditions however, direct tripping occurs through energy derived from the transformer rather than directly from the line voltage.

Abstract: A residual current transformer comprises an annular magnetic core which has not a gap nor sectional part crossing said magnetic core but has one or more narrow sectional area parts.

Abstract: For optimizing the manufacturing cost of the magnetic torus of a differential transformer, the volume is reduced in that the free volume of the central aperture is fully filled: only one turn for each primary conductor, the section of which is reduced, the adjacent parts of larger section forming heat sinks, the central part of the conductors having the form of circular sectors. An important saving is secured on the most expensive part of the relay.

Abstract: A one-piece insulated bus bar adaptor is removably attachable by spaced attachment sides having recesses for receiving retainer projections extending from the opposite end walls of a window type current transformer so that the adaptor is attached in a predetermined indexed position within the transformer opening with a bar mounting slot thereof having a predetermined fixed position for securing the current transformer.

Abstract: A current transformer is encapsulated in an injection molded layer of insulating material. The current transformer includes a secondary terminal assembly having individual terminals mounted on a terminal board. The terminal board is formed of a material that softens within the normal processing temperature range of the encapsulating material and forms an amalgamation therewith without a distinct interface between the terminal board and the encapsulating material which thereby provides a fluid-tight seal around the terminal assembly. The individual terminals have an intermediate shoulder disposed adjacent the top surface of the terminal board to prevent the molding material from covering the terminal assembly during the injection molding operation and, further, to provide a sealing surface for the molding material around the terminal assembly. A shorting bar is rotatably mounted between the terminals and rotates between a closed position shorting the terminals and an open non-shorting position.

Abstract: The isolating transformer has two windings galvanically separated from each other and each connected to a respective point, which points are set at various high voltage potentials. At least one additional transformer is provided in series with the isolating transformer, and has two galvanically separated windings, with one winding being galvanically separated from the isolating transformer and the second winding being galvanically connected to a first winding of the isolating transformer.

Abstract: A current transformer of the top core type for high voltage application is formed by a column of insulating material supporting a metal housing including an insulating body through which the primary conductor of the transformer passes. A plurality of cores each including a secondary winding of the transformer are enclosed in a grounded metal casing and extend around the central portion of the insulating body to form annular regions between the metal core casing and the metal housing. The dimensions and weight of the top part of the transformer are reduced by utilizing insulated metal rings provided for obtaining a uniform voltage distribution in the annular regions between the core casing and the housing. The insulated metal rings consist of metal foil between plates of insulating material and may completely fill the annular regions.The core casing includes planar end pieces abutting the insulated metal rings.

Abstract: A magnetic amplifier having a magnetic core in the shape of a hollow cylinder is provided with a gate winding comprising series-connected coaxial conductors passing through the center of the hollow core.

Abstract: In order to provide an electrically insulated and fluid-tight assembly for securing a current transformer to the inside of a dynamoelectric machine housing, a screw is inserted through an aperture in the machine's housing to secure the current transformer to a portion of the inner surface of the housing wherein a first insulating material is used to insulate the current transformer from the housing; a second insulator is used to insulate the screw from the housing; and an insulating cap is secured over the top of the screw. An O-ring provides a fluid-tight seal between the cap and the machine housing and a retaining ring is utilized to secure the cap over the screw's head within the machine housing. Secured to the lower part of the current transformer is a soft iron magnetic shield which is threaded to engage the screw and serves to support the current transformer.

Abstract: An inductive voltage transformer disposable between a high-voltage potential and a low-voltage potential has a first flux-conductive part surrounded by a high-voltage winding having a surface facing away from the flux-conductive part. A low-voltage winding is arranged at this surface of the high-voltage winding. A second flux-conductive part made of magnetically-conductive material is disposed in spaced relation to the first flux-conductive art so as to be adjacent thereto. Flux-conductive intermediate members connect the parts together to conjointly define therewith a cup-like core structure enclosing the high-voltage and low-voltage windings therein. The cup-like core is connectable to the high-voltage potential and the intermediate members are made of a material that is magnetically-conductive while at the same time being electrically insulative.

Abstract: Ground fault circuit breaker structure characterized by an insulating integral housing having side-by-side compartments that are separated by partition walls. A circuit breaker is located in each of two compartments and a ground fault detector is located in a compartment between the circuit breakers and isolated from the circuit breakers by the partition walls.

Abstract: A high voltage current transformer, and method of constructing same, including a primary winding having concentric leads, and a secondary winding on a magnetic core which is inductively linked with the primary winding. The magnetic core is a wound, two part core, with the two core parts being joined by stepped-lap joints. The secondary winding is a distributed winding having turns which are uniformly distributed about the complete magnetic circuit of the magnetic core. The conductor of the secondary winding is severed and the associated ends electrically re-connected, each time the conductor passes a stepped-lap joint.

Abstract: A measuring transformer for installation in the metal encapsulation of a switching installation is provided with at least one ring-shaped mounting shoulder which is clamped between flanges of the metal encapsulation.

Abstract: A power source for supplying stabilized current to electro-technological installations, comprising an induction-capacitance stabilizer with a power transformer and a short-length circuit comprised of a stationary bus conductor connected via flexible sections to an electro-technological installation, the primary winding of the transformer being uniformly distributed along the whole stationary bus conductor, embracing the latter cross-sectionwise, the stationary bus conductor being the secondary winding of the transformer.

Abstract: An improved radio-frequency transformer, particularly useful in conductive-body antenna systems, is provided in which telescoping of two or more portions of the primary of the transformer results in increased compactness, high effeciency and decreased cost.

Abstract: A single-conductor current transformer adapted to be installed into a fully insulated, metal-encapsulated high-voltage switching installation, whose cores and secondary windings are protected on all sides by a casing of electrically insulating material designed to provide an insulation for low voltage; the high voltage insulation is constituted by the insulating gas on the inside of the encapsulation of the high-voltage switching installation whereby the insulating casing forms the pressure housing for the insulating gas itself and is adapted to be secured with its end faces at the connecting flanges of the metal encapsulation of the high-voltage switching installation; metallic pipes are cast into the insulating casing within the outer edge area of the insulating casing for the return-conduction of the current, into which are adapted to be inserted connecting bolts for purposes of connection with the connecting flanges of the metal encapsulation.

Abstract: A measuring transformer arrangement with a capacitor bushing and devices for measuring voltage and current associated with the capacitor bushing is suitable for use in a high-voltage installation with metal encapsulation carrying several high-voltage conductors. The capacitor bushing provided for each high-voltage conductor is arranged in a bulkhead partition of the metal encapsulation and carries a current measuring device which includes at the periphery of the bushing at least one current transformer core with a secondary winding system mounted thereon.