Abstract: The present invention relates to a nonoriented electrical steel sheet coated on both surfaces with a cured insulative coating for providing a high level of surface resistivity to minimize interlaminar power losses. The cured insulative coating on the steel sheet includes, based upon 100 parts by dry weight, 20-60 parts of aluminum phosphate, 20-70 parts of at least one inorganic particulate silicate and 10-25 parts of an acrylic resin. The cured coating is formed from an acid aqueous suspension that may include up to 1 part by weight of a water-soluble organic solvent per each part of the resin. The aqueous suspension has a pH of about 2-2.5, a silicate particle size of 0.3-60 .mu.m, a resin particle size of less than 1 .mu.m, less than about 0.5 wt. % unreacted phosphoric acid and a specific gravity of about 1.0-1.3. The silicate may be one or more from the group consisting of aluminum silicate, aluminum potassium silicate and magnesium silicate.

Abstract: A high self resonant frequency inductor and method for making the same is described. The inductor comprises a plurality of horizontal conductor coils vertically spaced apart, including a top conductor coil and a bottom conductor coil, the top and bottom conductor coils each having a conductive termination. Dielectric material extends between and separates the conductive coils and the top and bottom terminations. The dielectric material has a plurality of via holes therein to provide communication between adjacent pairs of the conductive coils, the top conductive coil and top termination, and the bottom conductive coil and bottom termination. A plurality of conductive via connections extend through the via holes to connect the plurality of conductor coils, the top termination, and the bottom termination in series with one another.

Abstract: An ignition coil for an internal combustion engine and a method of making the same in which layers of the secondary winding are separated by a non-filtering/non-segregating material embedded in an electrically insulated ignition coil housing. The preferred non-filtering secondary winding separator is a solid filament, non-absorbing/non-adsorbing mesh, such as a nylon mesh. Using the non-filtering/non-segregating secondary winding separator prevents filler damming when an ignition coil housing is manufactured using a vacuum encapsulation and curing process in which an encapsulation compound (e.g. a thermal setting epoxy) has solid additives (e.g. sand fillers). Non-absorbing/non-adsorbing separators are also advantageous because the separators do not alter the chemistry of the encapsulation compound.

Abstract: An isolation transformer comprises two core pieces mounted to cooperate to provide flux paths, one of the core pieces being shaped so that a central flux path is defined by a central leg of the core, at least two magnetically coupled windings surrounding the central flux path, and an isolation layer sandwiched between the windings.

Abstract: High quality factor (Q) spiral and toroidal inductor and transformer are disclosed that are compatible with silicon very large scale integration (VLSI) processing, consume a small IC area, and operate at high frequencies. The spiral inductor has a spiral metal coil deposited in a trench formed in at dielectric layer over a substrate. The metal coil is enclosed in ferromagnetic liner and cap layers, and is connected to an underpass contact through a metal filled via in the dielectric layer. The spiral inductor also includes ferromagnetic cores lines surrounded by the metal spiral coil. A spiral transformer is formed by vertically stacking two spiral inductors, or placing them side-by-side over a ferromagnetic bridge formed below the metal coils and cores lines. The toroidal inductor includes a toroidal metal coil with a core having ferromagnetic strips. The toroidal metal coil is segmented into two coils each having a pair of ports to form a toroidal transformer.

Abstract: An article of insulation, especially adapted for insulating corners, is provided. The article is constructed in the form of an elongated flexible sheet capable of sustaining and retaining at least one longitudinal fold therein and having generally a beginning end and a closing end and first and second, generally opposite longitudinal sides thereof. Each longitudinal side has a plurality of protrusions or tabs extending outwardly therefrom along the length of each side, with each protrusion being separated from adjacent protrusions such that, upon folding the sheet longitudinally along its centerline to form overlapping halves folded upon one another, the protrusions along the length of the first side overlap the separations along the length of the second side, and vice versa. The article has a second fold extending longitudinally thereof along the bases of the protrusions such that the overlapping protrusions form substantially a right angle with the remaining portion of the sheet.

Abstract: A method for the manufacture of a rotary transformer in accordance with the present invention comprises the steps of forming two cylindrical stator ferrite blocks with the same inner diameter but different outer diameters and two cylindrical rotor ferrite blocks with different inner diameters but the same outer diameter; smoothly grinding the inner and outer surfaces of the above cylindrical rotor and stator ferrite blocks and cutting them into a plurality of rotor and stator rings, respectively; applying a bonding agent to the top and the bottom surfaces of the rotor and stator rings and layering them in order to thereby form a plurality of rotor channel grooves and stator channel grooves; inserting a catalyst between the layers that form the stator and rotor channel grooves; heating and pressing together the layered rotor and stator rings in a furnace; and, after heating and pressing, threading the coils into the channel grooves and combining the rotor and stator transformers to thereby complete the rotary

Abstract: An electromagnetic steel sheet having a corrosion-resistant electrically insulating film. The insulating film is formed by spraying and baking, on the steel sheet, a treating liquid containing an emulsion of fine resin particles, a reducing agent and an accelerator. The emulsion of fine resin particles exhibits a weight change peak temperature of not lower than about 400.degree. C. as measured by differential thermal weight measurement conducted while raising the emulsion temperature at a constant rate of temperature rise. The emulsion also substantially resists when contacted by phosphoric acid. The reducing agent is a phosphate ion aqueous solution containing a metal. Also disclosed is a corrosion-resistant core made from the electromagnetic steel sheet.

Abstract: In order to prevent clouding of a hard disc and a polygon mirror, a tin-free electrodepositing coating composition is used as an insulating coated film of a motor for driving the hard disc and polygon mirror.

Abstract: A magnetic core obtained by laminating or winding a magnetic material ribbon and an electrical insulating material wherein the magnetic core has the relationship of 0.5 a.ltoreq.b<a in which the width of the magnetic material ribbon is "a", and the width of the electrical insulating material is "b".

Abstract: A transformer in which a magnetic medium provides flux paths within the medium, two or more windings enclose the flux paths at separated locations along the paths, and an electrically conductive medium, arranged in the vicinity of the magnetic medium and the windings, defines a boundary within which flux emanation from the magnetic medium and the windings is confined and suppressed. In a transformer constructed in accordance with the present invention, both controlled values of leakage inductance and the benefits of separated windings can be achieved. The conductive medium can be configured to reduce the leakage inductance of a controlled-leakage inductance transformer (e.g. for use in a zero-current switching power converter), having separately located windings, by at least 25%, and can be configured to reduce the leakage inductance of a low-leakage inductance transformer (e.g. for use in a PWM power converter), having separately located windings, by at least 75%.

Abstract: An integrated and drop-in EMI filter that features common-mode and differential-mode noise filtering capabilities is disclosed. The common-mode portion and the differential-mode portion of the filter are independent of each other in that the two filter portions may be made out of different ferrites, also in that, the an increase in the filtering capability in one mode, such as having an increased number of turns in the winding, would not affect or reduce the filtering capability of the other mode, such as reducing the overall throughhole depths a conductor travels.

Abstract: This transformer core and coil assembly comprises (a) a low voltage coil surrounding a coil window and including first and second coil legs on opposite sides of the coil window, (b) a first plurality of side-by-side amorphous-steel core loops surrounding one of the coil legs, and (c) a second plurality of side-by-side amorphous-steel core loops surrounding the other of the coil legs. Extending between said coil legs in a position between two of said side-by-side core loops in the first plurality and between two of said side-by-side loops in the second plurality is a brace of plate form and of electrical insulating material for blocking motion of said coil legs toward each other in response to coil-collapsing forces developed by short-circuit currents through the low voltage coil, thereby protecting the amorphous-steel core loops from damage by these short-circuit produced forces tending to collapse the coil.

Abstract: An apparatus and method for structurally restraining and reinforcing an amorphous metal core of an electrical transformer employs an adhesive bonding agent applied to the lamination edges and protective layers of the core followed by adhesion of a woven fabric thereto to form a highly permeable oil/air interface with the lamination edges of the amorphous material, while providing an effective chip containment system thereto. A temporary guide sleeve aids the core and coil lacing operation. A method for breaking performance inhibiting interlaminar bonds between the amorphous layers of the core is also disclosed.

Abstract: An ignition coil assembly to be inserted into a plug hole of an engine so as to be directly coupled to an ignition plug. The ignition coil assembly is equipped with a central iron core and primary and secondary coils wound around the central iron core. The central iron core is formed by bundling magnetic wire rods to have a cylindrical configuration. This arrangement allows the ignition coil assembly to be easily and effectively inserted into the plug hole of the engine.

Abstract: A conductor pattern for forming coils and lead-out electrodes which are led out from the coils are formed on a magnetic substance sheet. Furthermore, said magnetic substance sheet is provided with through-holes for connecting the conductor patterns. The magnetic substance sheets disposed respectively just over and just under the conductor pattern that becomes the lead-out electrodes are coated with non-magnetic material paste. A laminated chip common mode choke coil is produced by laminating these magnetic substance sheets and baking them integrally and thereafter forming external electrodes. The non-magnetic material diffuses into the magnetic substance sheet by baking the lamination of the magnetic substance sheets, and the permeability of that portion becomes low. Therefore, the magnetic reluctance around the lead-out electrode becomes high, thus reducing leakage flux around that portion. Thereby, coupling between two coils formed in the choke coil becomes good.

Abstract: A finished transformer core (48) includes a core (2) of wound amorphous transformer core material (4) to which rigidifying bonding material (22) is applied to the ends (12, 14) of the core. The bonding material does not cover the entire ends but leaves gaps (24) to permit fluid flow between the ambient environment and the interlamination voids (16) which exist between the layers (18, 20) of the wound material. The core, rigidified by the bonding material, is housed within a fluid permeable containment assembly (28). The containment assembly typically includes fluid permeable filter material (32, 34, 36, 38) which allows transformer oil and air to pass through the material but will trap solid particles of core material within the containment assembly.

Abstract: Disclosed are a magnetic ribbon on at least one surface of which fine particles formed of a nonmagnetic inorganic substance having insulating properties are attached and a magnetic core around which this magnetic ribbon is wound or on which it is laminated. The fine particles serve as a spacer to form a layer of air between adjacent layers of the magnetic ribbon.

Abstract: A method of manufacturing a core for an electrical inductive device. A blind hole is provided through a stack of laminations into which an oil or an epoxy resin adhesive is placed. The blind hole provides a slow release for the oil to the outer surfaces. This obviates the contamination of the outer surfaces of the coil during manufacture as in the case with a dipping procedure. When the epoxy resin adhesive is employed in the blind hole, a wicking action takes place for better fastening of the laminations together. In another embodiment of the fastening feature, epoxy resin adhesive is molded to the outside of the end piece laminations as well as through a passage in the laminations. An improved resulting core is also provided.

Abstract: A magnetic core comprises at least one layer of magnetic film composed of an amorphous alloy and an electrically insulating film made of polyimide. Powder materials having a property for alleviating mutual influence between the magnetic thin film and the insulating film during a heat treatment thereof are stuck to a surface of the magnetic film or the insulating film. The magnetic film and the electrically insulating film are alternately wound up in a predetermined shape with powder material interposed therebetween to thereby form a magnetic core.

Abstract: A protective device for a hermetic motor-driven compressor comprises a protective device main body and an insulating layer made of a heat-resisting insulating material having a heat-resisting temperature of 155.degree. C. or higher, wherein the insulating layer surrounds the main body.

Abstract: A wound magnetic core constituted by (a) a thin ribbon made of a fine crystalline, soft magnetic Fe-base alloy having the composition represented by the general formula:(Fe.sub.1-a M.sub.a).sub.100-x-y-z-.alpha. Cu.sub.x Si.sub.y B.sub.z M'.sub..alpha.wherein M is Co and/or Ni, M' is at least one element selected from the group consisting of Nb, W, Ta, Zr, Hf, Ti and Mo, and a, x, y, z and .alpha. respectively satisfy 0.ltoreq.a.ltoreq.0.5, 0.1.ltoreq.x.ltoreq.3, 0.ltoreq.y.ltoreq.30, 0.ltoreq.z.ltoreq.25, 5.ltoreq.y+z.ltoreq.30 and 0.1.ltoreq..alpha..ltoreq.30, at least 50% of the alloy structure being occupied by fine crystal grains having an average grain size of 1000 .ANG. or less; and (b) a heat-resistant insulating layer having a thickness of 0.5-5 .mu.m formed on at least one surface of the thin ribbon, the heat-resistant insulating layer being made of a uniform mixture of 20-90 weight %, as SiO.sub.

Abstract: A welding apparatus is disclosed to include an electrically insulating casing, first and second welding electrodes, and a welding transformer having a toroidal core, a multi-turn primary winding and a single-turn secondary winding. The core includes a grain-oriented silicon steel material coiled with an insulator. The primary winding has turns axially wound about the core. The secondary winding includes two conductive arm sections which are connected to the electrodes and a wound section including conductive wire cable which electrically connects the two arm sections. One of the arm sections can provide the frame member to support the transformer. The apparatus is suitable for spot or linear welding.

Abstract: The present invention concerns a transformer of the ferrite closed magnetic circuit type, with a gap.The gap is filled with a mastic such as the polysulphide or polyurethane mastics having a Shore hardness with constant behaviour as a function of temperature.

Abstract: A 60 VA transformer is described. A recycling circuit breaker mounted on and connected in series with the secondary winding of the transformer preserves the integrity of the transformer and permits its continued use after a short circuit. A thermal fuse mounted on and connected in series with the primary winding provides short circuit protection in the event the circuit breaker fails in a closed position. Achievement of this end is attained by decoupling the transformer windings to reduce short circuit, secondary current flow. Decoupling is provided by spacing the transformer windings a distance of about 0.090 in. A controlled failure mode provides energy limiting protection for the secondary load circuit in the event of circuit breaker failure in the closed position. Controlled failure is provided by the use of secondary insulation which melts within one minute of a short circuit, permitting turns of the secondary winding to short and reduce current flow to eight amp. within the one minute period.

Abstract: Method for forming a laminate and a product formed thereof. A thin layer of oil is applied to a facing surface of at least one a plurality of adjacent laminations. The laminations are passed between a pair of rollers which apply sufficient pressure to remove excess oil between the facing surfaces. The air between the facing surfaces is displaced and the remaining oil forms a seal to prevent reentry of the air. The laminate is tightly held together to permit handling or fabrication without delamination.

Abstract: This amorphous steel core transformer comprises: (i) a coil subassembly having a coil window of generally rectangular cross-section bounded by two end faces and two side faces, at least one of the side faces being slightly concave, and (ii) a core having a leg that fits within the coil window and comprises superposed aligned strips of amorphous steel stacked in the direction of the leg thickness and between said side faces. Each strip has two edges and, disposed between the two edges, a width that approximates the distance between the end faces of the coil window. The strips are further characterized by a slightly greater thickness in their central region than in the region of their edges. The core leg has a thickness that is substantially less in both edge regions of the strips than in the central region of the strips, thus rendering the leg capable of fitting more tightly within said coil window.

Abstract: A low-profile, high-frequency power transformer is comprised of a plurality of insulated ferrite slabs formed in a stacked array. In one embodiment a pair of slots are defined through the stacked array of insulated slabs. A single-turn metallic ribbon conductor is then looped through each pair of slots to form a corresponding first and second loop which are coupled in a magnetic flux circuit with each other through the stack. The distance separating one pair of slots is unequal to the distance separating the other pair of slots so that the loops formed by the ribbons have a corresponding unequal cross section. Hence the ratio of the voltages on the ribbons is proportional to the ratio of the respective cross-sectional areas of the ribbon loops. In another embodiment, a third ribbon is added having a cross-sectional loop area equivalent to the second ribbon to provide symmetrical, single-turn output coils.

Abstract: An inductance element comprises at least one annular core formed by a magnetic foil belt wound in a volute form and comprising magnetic thin films deposited on a tape-like thin plate; and at least one wire wound on said core. The magnetic thin films are provided with an axis of easy magnetization directed in the direction of width of said magnetic foil belt. Further, the magnetic thin films are thicknesswise separated into a plurality of discrete layers by at least one intervening resistance layer having a resistivity in the range from 10.sup.2 .mu..OMEGA.. cm to 10.sup.6 .mu..OMEGA..cm. Alternatively, the core may be formed by plural pieces of magnetic foil belt comprising magnetic thin films deposited on a tape-like thin plate, said plurality pieces of magnetic foil belt being insulated from each other and provided in a laminated form.

Abstract: An inductive device comprising a ferromagnetic core which has two approximately U-shaped core halves (9, 11) connected together with their limbs (9', 11'; 9", 11") facing each other so that they enclose a core window (17). Each core half (9, 11) is constructed substantially from a packet of mutually parallel strips of an amorphous ferromagnetic material. Filling members (21', 21") consisting of a solid non-ferromagnetic material are placed between the free ends of each pair of facing limbs (9', 11'; 9", 11"), and in the space (23', 23") between the ends the filling members extend from the core window (17) in the outward direction over at most half of the width of the core limbs. A decrease of the magnetic permeability of the core material as a result of decreasing temperature is compensated by a decrease of the width of the air gaps (23', 23") between the free ends of the limbs (9', 11'; 9", 11").

Abstract: This transformer comprises preformed coil structure and a wound core of closed-loop configuration extending about a window and having joints in a localized region thereof that allow the core to be opened at the joints to permit insertion into the window of the preformed coil structure. The core comprises superposed laminations of thin amorphous ferromagnetic strip material which extend around the core from the localized joint region. The laminations include predetermined portions adjacent the joints that are displaced to provide a wide opening into the core window for insertion of the coil structure. A coating of adhesive bonding agent applied before said displacement is present on the lateral edges of the laminations in regions of the core not including said predetermined portions, thereby holding the laminations in correct assembled relationship when the core is opened, yet without interfering with displacement of said predetermined portions.

Abstract: A magnetic core containing amorphous metal, suitable for use with electrical inductive apparatus, such as transformers. The desired physical dimensions of the magnetic core are maintained, without adversely stressing the core, by a composite, conformal coating applied to the core edges. The composite coating includes a rigid high strength outer structure and a low stress, adhesive inner structure which cooperatively provide mechanical support and stress protection for the magnetic core, while maintaining its configuration.

Abstract: A "Spacercore" design is used to provide the cores of the electromagnets which are used to bias ferrite slabs in phase shifters of a high power RF attenuator. The phase shifters require a given flux to provide a phase shift from zero to 90.degree.. With laminations of high permeability silicon steel, the core weight may be substantially reduced by including a filler comprising spacers of non-magnetic material (such as lightweight transformer pressboard. With 14-mil silicon steel laminations and 64-mil spacers, this construction provides a core which weighs 25 percent of a full ferrite core for the same flux density.

Abstract: A circuit for the efficient generation of high voltage pulses for the initiation of conduction in gaseous discharge lamps, the effective suppression of potentially harmful voltage surges resulting from derangement of one or more electrical, current-carrying mechanical, or mechanical components within the overall gaseous discharge lighting apparatus, and reduction of radio frequency interference resulting from the normal and deranged operation of the overall gaseous discharge lighting apparatus. The ignitor/suppressor includes a semiconductor switching device, a capacitor of special characteristics, a transformer of special construction, and a resistor for the generation of high voltage pulses. The ignitor/suppressor also includes a semiconductor switching device, a capacitor of special characteristics, and a resistor for the effective suppression of abnormally high voltages.

Abstract: A core shunt packet for reducing the telephone influence factor in a transformer of the type having a core formed from strips of magnetic material arranged in end-to-end relation forming a series of staggered gaps at one end of the core, the core shunt packets including one or more steel laminations mounted in an envelope, the envelope being mounted on the side of the core in a position to bridge the gap area on the core with a sheet of insulation located between the envelope and the side of the core.

Abstract: An electromagnetic apparatus is provided with a magnetic core and a segmented electrical winding. The core has an enclosed trunk defining a central opening. At least three coil sections of the electrical winding encircle the trunk and are circumferentially spaced about the periphery of the core.

Abstract: A magnetic core containing amorphous metal, suitable for use with electrical inductive apparatus, such as transformers, and methods of constructing such a magnetic core. The desired physical dimensions of the magnetic core are maintained, without adversely stressing the core, by a composite, conformal coating applied to the core edges. The composite coating includes a rigid high strength outer structure and a low stress, adhesive inner structure which cooperatively provide mechanical support and stress protection for the magnetic core, while maintaining its configuration.

Abstract: The present invention relates to a core of magnetic amorphous alloy. A thin strip of such alloy is wound and then cut to provide, e.g., C-shaped pieces. A pair of C-shaped pieces is assembled to provide the core. Conventionally, the magnetic properties, e.g., the watt loss, of the core are impaired at the cut ends of a thin strip due to the formation of burrs.The present invention is characterized by providing the cut ends with a thickness substantially the same as the thickness of the non-cut portion of the thin strip and by polishing the cut ends substantially parallel to the major surface of the thin strip, thereby improving the magnetic properties of the core.

Abstract: A microcoil having a winding on a composite core made up of a portion of substantially magnetic material and a portion of substantially non-magnetic material. The winding is split so that a part of the magnetic material core portion is exposed, and a laser is used to remove material from the exposed part of the magnetic core portion. The inductance of the coil is measured during the removal of the magnetic material, and the inductance of the coil is trimmed to a desired value through the removal of an appropriate amount of magnetic material. The non-magnetic core portion serves as a support structure for the portions of the winding on the core even if a substantial portion of the magnetic material is removed.

Abstract: An induced current heating probe is of thimble form and has an outer conducting sheath (30) and a water flooded flux-generating unit formed from a stack of ferrite rings (10) coaxially disposed in the sheath. The energizing coil (14) is made of solid wire which connects at one end (16) with a coaxial water current tube (15) and at the other end (17) with the sheath. The stack of ferrite rings (10) may include non-magnetic insulating rings (11) which help to shape the flux.

Abstract: An annular form of magnetic steel comprises a plurality of elongated sheets wound in superposed relationship about a reference axis. The sheets respectively define reference annuli, which are of progressively greater diameter as the annular form is wound about said reference axis. At least one of said reference annuli has a substantially greater diameter at one edge of the annular form than at the opposite edge of the form. At least some of the sheets that are located radially outward of said one reference annulus are provided with thickening means giving these sheets an effective thickness at one side greater than at their other side. Said one side is located on the opposite side of the longitudinal center line of the sheet from said one edge of the annular form.

Abstract: The present invention relates to a saturable core which consists of a coiled thin strip of an amorphous magnetic alloy. The present invention provides a saturable core having a high .DELTA.Bs, a low power loss, a good saturation property, and low secular changes of the magnetic properties, due to determining the coiling direction of the saturable core so that it is the same as that of a coil heat treated.

Abstract: An electromagnetic apparatus is provided with a magnetic core and a segmented electrical winding. The core has an enclosed trunk defining a central opening. At least three coil sections of the electrical winding encircle the trunk and are circumferentially spaced about the periphery of the core.

Abstract: Transformer cores are made electrically conductive during impulse voltage condition when a certain voltage is attained by a coating of semiconductor material applied to the edges or surface of the core laminations. Under ordinary operating conditions the semiconductor material provides a high resistance path to charges in the core. Upon the occurrence of a high voltage impulse, the semiconductor material rapidly equalizes the charges in the laminations and so avoids the danger of breakdown of the insulating coatings between individual laminations.

Abstract: This induction winding includes a magnetic core formed by a vertical stack of iron disks separated by air gaps. The disks (8) include a plurality of sector-shaped portions (1) each of which is constituted by a succession of magnetic laminations (6), a first part (12,13) of these laminations are all of identical length and a second part (14) are of regularly decreasing length from one lamination to the next. The direction (F.sub.1) in which the laminations are rolled in the mill is perpendicular to the axis (7) of the winding. The increased magnetic loss that this causes is compensated by the improved filling coefficient that can then be readily obtained.

Abstract: A magnetic core for use with electrical windings characterized by a plurality of groups of butt-jointed laminations of high permeability, amorphous material with each lamination group having a layer of protective material surrounding the outermost lamination and comprising a strip of material having a melting point above the temperature range of from about 340.degree. C. to 420.degree. C., whereby each lamination group is protected from damage during handling.

Abstract: Transformer cores are made electrically conductive during impulse voltage condition when a certain voltage is attained by a coating of semiconductor material applied to the edges or surface of the core laminations. Under ordinary operating conditions the semiconductor material provides a high resistance path to charges in the core. Upon the occurrence of a high voltage impulse, the semiconductor material rapidly equalizes the charges in the laminations and so avoids the danger of breakdown of the insulating coatings between individual laminations.

Abstract: In a transformer for use in a receiver set, a non-magnetic material arranged in part of a closed magnetic path established by a magnetic core is made of a plastic material such as paper mash or silicon putty. The non-magnetic material is pressurized and deformed so as to set the inductance of a coil mounted on the magnetic core to a predetermined value.

Abstract: An impedance coil core which includes a plurality of core legs and yokes which interconnect the core legs in an assembled condition of the core is provided with aligned recesses in the yokes and in the core legs for accommodating tensioning bolts which extend into the recesses and press the yokes against the core legs in the assembled condition. Each of the core legs includes a plurality of laminated assemblies including sheet metal elements. Those portions of the yokes and at least of the laminated assemblies adjoining the latter are provided with non-magnetic intermediate layers in the central region which is provided with the recesses. The intermediate layers in the core legs are wedge-shaped and diverge toward the adjacent yokes, and the intermediate layers in the yokes are cross-sectionally rectangular.

Abstract: The light weight non-saturating spaced core inductor that is made of altete layers of magnetic and light weight non-magnetic materials to provide a structure that is light in weight yet has the non-saturating inductor characteristics required for certain circuits that are subject to over-load.