Abstract: Packs of laminations and a method of assembling the packs of laminations to make a core of an electromagnetic device such as a transformer or motor are described. First and second packs of complementary laminations (12, 14) are provided that fit relatively freely together and have interfitting formations e.g. dovetail formations (16) and projections (18). Preferably adjacent laminations of each pack are attached. The first and second packs of laminations (12, 14) are held positively together in mechanical contact e.g. in a jig. The formations (18) on one or both of the laminations are then deformed to engage the formations (16) of the other lamination to clamp the first and second packs of laminations (12, 14) together. In an alternative form the first and second packs of laminations clip together.

Abstract: An electrical connection to a coil winding of a coil winding assembly that is comprised of a coil spool that carries the coil winding. The coil spool has an integral terminal supporting portion that is provided with an axially extending slot. A terminal, that can be formed of steel wire, has a rippled or undulated portion that is disposed within the slot. The rippled portion engages surfaces of said slot to prevent movement of the terminal out of the slot. An end portion of the coil is wrapped around a connector portion of the terminal and soldered thereto.

Abstract: An ignition coil, in particular for an internal combustion engine for an automotive vehicle, comprises, integrated into a housing, a magnetic assembly which includes a magnetic core mounted within a primary spool, with a secondary spool arranged coaxially around the primary spool. The spools carry the primary winding and the secondary winding, respectively, and the coil further includes a magnetic flux return circuit and a high tension connection assembly. The latter includes an insert member secured in the secondary spool, a high tension busing and a high tension guide member in which the high tension output member is mounted, and is characterized in that the high tension output member comprises a spring.

Abstract: An induction coil having two split-ring cores which are self-aligning. Each core is semi-circular, one core being fixed within a first jaw, and the other free to move within a second jaw. The jaws are pivotally attached and biased to form a closed loop in the relaxed state. A spring next to the free core urges the free core against the fixed core as the jaws are brought together. This action insures a proper contact between core ends which is necessary for optimum inductive coupling.

Abstract: In a stationary electromagnetic induction unit according to this invention, a plate-like coil is constituted by a plurality of coil elements wound in parallel. Therefore, a conductor width of the coil element becomes small, and a stray loss caused by a leakage flux vertically interlinked with the surface of the coil element, namely, the plate-like coil is reduced.

Abstract: An encased transformer that comprises a bobbin including a plastic-molded cylindrical portion and upper and lower collars formed respectively at upper and lower ends of the cylindrical portion, a magnetic element extending centrally through the cylindrical portion, primary and secondary coils wound round the outer periphery of the cylindrical portion, comb-shaped metals terminal formed on the pair of lower collars by insert molding, the comb-shaped portion of each metal terminal being bent at generally right angles, the metal terminals being further bent at right angles and outwardly horizontally at an end portion thereof so that the metal terminal is substantially Z-shaped, a straight portion of the metal terminal positioned midways of the Z-shaped being fixedly held in position between the inner wall of a case and a frame wall having recessed terminal grooves into which are individually fitted metal terminals provided in a plastic square bottom plate.

Abstract: An inexpensive autotransformer assembly adapted to withstand and operate under stingent conditions for permitting the flow of a fluid in both the axial and radial directions therethrough to cool both the core and the windings is disclosed. A first embodiment comprises an autotransformer assembly having a core and at least two groups of windings spaced apart thereon. The core includes a central cooling channel and a plurality of radial channels extending outwardly from the central cooling channel and terminating at openings in the outer surface of the core. A second embodiment comprises an autotransformer assembly having a core and at least two groups of windings thereon. A plurality of longitudinal spacers disposed on the outer surface of the core serve as a means for spacing the windings from the core in order to provide an axial coolant path along the outer surface of the core.

Abstract: An improved conductor for an inductor device of the type having varying current carrying requirements along the length of the conductor, the improvement comprising having the conductor contoured such that the cross sectional area of the conductor varies substantially directly as the current carrying requirements of the conductor vary. In one embodiment, a coil for a variable transformer is cut from a cylinder of conductor material by numerically controlled machining, producing a contoured conductor and eliminating the requirement for coiling or winding of the conductor.

Abstract: A lamination type inductor has a plurality of ferrite sheets assembled one above the other and laminated together, the uppermost and lowermost sheets being end sheets having lead-out conductor patterns thereon and conductor patterns on the surfaces of the end sheets which face each other which are connected to the lead-out conductor patterns and which are for connection to conductor patterns on intermediate sheets, and a plurality of intermediate ferrite sheets, each having a conductor pattern on one surface thereof which corresponds to a 0.25 turn of an inductor coil and a conductor pattern on the other surface which corresponds to a 0.5 turn of an inductor coil, each ferrite sheet having an opening therethrough through which the conductor patterns of the 0.25 and 0.5 turn are electrically connected to form a 0.75 turn of an inductor coil on each ferrite sheet.

Abstract: A multiple ignition coil, in particular for an internal combustion engine for an automotive vehicle, has a casing in which are integrated at least two magnetic assemblies, at least two magnetic flux return circuits constituting a metallic armature of the casing, and mounting assembly for anchoring the coil to the vehicle, these mounting assembly comprising metallic cores which are entirely separate from the metallic armature and which are retained by moulding within projecting bosses of the casing.

Abstract: An inductance coil which is completed by casting resin around the body comprising a bobbin wound with a coil and a couple of U-shaped cores inserted in a center hole of the bobbin with the end faces adherent to each other to form a closed-loop magnetic path. The couple of cores are coated with mold releasing agent to assure the adhesion of the end face.

Abstract: A high voltage coil manufactured by alternately winding coils and mounting rigid insulating tubes on a coil form having end plates with terminals. After each coil is wound with its ends terminated at the end plates, a first axially slitted insulator tube is snapped over the coil with about a one-quarter inch gap and a second tube with no gap is snapped over the first rotationally displaced 180 degrees enclosing the gap which forms a flow conduit. Another coil is wound on the second tube and the process is repeated to form as many as six coils. Potting material is applied to the completed assembly and vacuum impregnated, and the tube conduits form flow paths to achieve complete impregnation.

Abstract: An air core reactor of the type having a plurality of coaxial coil windings connected electrically in parallel by structurally rigid spiders at opposite ends of the reactor. There are two electrically conductive spiders at least one end of the reactor. Selected ones of the coil windings are connected to one of the two spiders and further selected ones of the coil windings are connected to the other of the spiders at the one end. In the preferred form the windings connecterd offset from one another around the coaxially disposed coils. In a further preferred embodiment, there are two electrically conductive spiders at each of opposite ends of the coaxial coils. In a still further preferred form, at least some of the coil windings are wound at least two conductors high with the same number of turns and wherein the ends of said two conductors are circumferentially offset from one another by preferably 180.degree..

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 common-mode choking coil comprises a closed magnetic path core which is formed, for example, by combining two U-shaped cores. Two coils wound in opposite respective directions are mounted on two legs of the closed magnetic path core. These coils are formed by single-layer winding. That is a conductor wire is wound in only one layer, for example, around a bobbin. Then, the bobbins whereon the conductor wire is wound are mounted on the two legs of the closed magnetic path core. For the conductor wire used for the coil, a material having a spring property may be used. Utilizing this spring property of the coil, the closed magnetic path core can be held together by the coil, whereby the two U-shaped cores can be combined. Also, the two coils are identified by colors according to the winding direction of the respective conductor wires.

Abstract: A conductive film magnetic component such as an inductor or transformer includes a conductive film winding having a generally serpentine configuration when disposed in a plane. This film is folded to form a stack of layers with each "layer" comprising part of a winding turn and with successive "layers" connected at the folds via the continuous conductive film. The conductive film may be self-supporting and coated with a dielectric layer or may be disposed on a dielectric membrane. The film and membrane are preferably patterned photolithographically.

Abstract: An ignition coil for developing spark plug firing voltages. The magnetic current for the coil comprises an axially extending core that joins axially spaced annular parts. The core and parts can be formed of iron particles in a binder of electrical insulating material. A primary winding is disposed about the core and a secondary winding is disposed about the primary winding. An axially extending circular part that is formed of magnetic material is positioned to provide air gaps with outer surfaces of said annular parts. The circular part forms a shield that increases the capacitance of the secondary winding. The total stored magnetic energy does not vary substantially with variations in air gap length. The cross-sectional area A of the air gap is large as compared to the length L of the air gap so that the ratio A/L does not vary much with variations in L.

Abstract: A broadband RF transformer design is described that facilitates the construction of a broadband impedance transformer in a compact, planar format, while retaining ease of assembly and manufacture. Broadband operation is achieved through the use of a slotted low-impedance winding structure, common-manufacture ferrite elements, and the optional placement of reactive elements between winding turns. By virtue of construction, thermal performance is enhanced, allowing operation at power levels not previously possible. The invention accommodates functional tuning via laser or abrading techniques. Also, the winding configuration eliminates the need to access the center of a spiral for the purposes of establishing a ground connection.

Abstract: An ignition coil comprises at least one magnetic assembly, each of which has a central magnetic core, around which two formers, namely a primary and a secondary former, are arranged coaxially. The formers carry the primary and secondary windings respectively, and the magnetic assembly further includes retaining means adapted to position and secure the primary former within the secondary former. These retaining means comprise steps formed integrally in a tubular cavity of the secondary former and cooperating with one of the end plates of the primary former.

Abstract: A device for measuring electric current includes a toric core having a gap that establishes a pair of opposed end faces, and a continuous conductor having terminal ends and wound around the core in contiguous turns forming a toric solenoid interrupted by the gap. The solenoid has first and second ends adjacent the respective end faces of the core, and the conductor at each end of the solenoid passes through the core and extends along the axis thereof from the opposed end faces of the core such that the terminal ends of the conductor are located diametrically opposite the gap. A first compensation coil is serially connected to said first end of the solenoid such that the first coil overlies the first end of the solenoid to which the first compensation coil is connected.