Abstract: A stick-shaped ignition coil includes a center core, a primary coil, a secondary coil, and a body case that are substantially coaxially arranged relative to each other. The ignition coil further includes an igniter, a head case, a holder, and an electrically insulative resin. The head case accommodates the igniter. The head case is provided to an upper end portion of the body case. The holder is arranged between the igniter and upper ends of all the center core, the primary coil, and the secondary coil. The electrically insulative resin is filled in a first space, which is formed among the center core, the primary coil, the secondary coil, the body case, and the holder. The holder has at least one resin flow hole, through which epoxy resin is supplied into the first space, and at least one vent hole, through which air in the first space is vented to an outside.

Abstract: An ignition coil device has a secondary spool, a secondary coil wound around the secondary spool, a coil insulating resin material that is impregnated into and cured in spaces between the windings of the secondary coil, a primary spool arranged on the secondary coil, a primary coil wound around the primary spool, and a high voltage tower that is arranged on one end side in the axial direction of these parts and is mounted with an ignition plug. At least one of two parts of the primary spool and the high voltage tower and the coil insulating resin material are integrally molded out of the same resin.

Abstract: A common-mode choke coil includes a core having flanges disposed at both ends and a winding section arranged between the flanges. Electrodes are disposed in the flanges, while two pieces of wire are wound around the winding section and ends of the pieces of wire are connected to the electrodes. A ferrite plate with a relative magnetic permeability that is smaller than that of the core is attached on the upper surface of the flanges with an adhesive so as to cover the wire.

Abstract: The present invention discloses a laminated chip electronic device and a method of manufacturing the same. In the laminated chip electronic device and the method of manufacturing the same according to the present invention, a body is made of a non-linear resistance coefficient material and has a plurality of conductive layers formed therein; an insulating layer is formed on the top, bottom, front and back surfaces of the body; and two electrodes are formed at the two ends of the body and electrically connected to the terminals of the conductive layers, respectively. Furthermore, in the present invention, two soldered interface layers are formed on the two electrodes, respectively.

Abstract: A high current, low profile inductor (IHLP) includes a conductive coil molded within an inductor body substantially free from ferrite materials and comprising powdered iron materials. The method comprises pressure molding the inductor body substantially free from ferrite materials and comprising a powdered magnetic material within the hollow core of the coil and completely around the coil so that the magnetic material is substantially free from voids therein without shorting out the coil.

Abstract: A drum type core comprises: a flanged cylinder including a cylinder portion with a coil wound thereon, and a flange portion connected integrally with one end of the cylinder portion; and a flange piece having on its one side an engaging hole, into which the other end of the cylinder portion of the flanged cylinder is inserted. The flanged cylinder and the flange piece are made of respective different materials. The flanged cylinder has a higher permeability and saturation flux density than the flange piece, while the flange piece has a higher surface electrical resistance than the flanged cylinder. The flanged cylinder is entirely coated with a heat-resisting epoxy resin except an outer side of the flange portion. The flange piece is provided with terminal pins, around which lead wires of the coil passing by the circumference of the flange piece are bound.

Abstract: A shock absorbing assembly reduces impact forces on a terminal of a spark plug that is mounted within a spark plug bore of an internal combustion engine when a pencil ignition coil is mounted thereto. The shock absorbing assembly includes a plug cup that is fixedly secured to the terminal end of the spark plug. A case cup is movably mounted to the plug cup. The case cup includes a resistor receptacle for receiving an end of a resistor therein. The shock absorbing assembly also includes a cup spring that extends between the plug cup and the case cup. The cup spring absorbs the impact forces of mounting the pencil ignition coil to the terminal of the spark plug.

Abstract: An inductor assembly includes a coil or coils of insulated conductor material defining an inside volume, an inner core of magnetic core material located within the inside volume, and an outer core of magnetic core material including structure overlying the coil and inner core and having opposite inner walls facing polar ends of the coil and core, such that at least two magnetic gaps exist between ends of the inner core and the opposite inner walls of the outer core. A method for making the assembly is also disclosed.

Abstract: With an ignition coil module comprising a coil system which includes a primary winding and a secondary winding and a flux conducting, soft magnetic device to increase and/or to conduct a magnetic flux generated by one of the windings and comprising an electronic component to control the coil system which has an electrical circuit and a heat sink to cool the electronic component, at least one section of the heat sink is connected to a section of the flux conducting device in a thermally conductive manner such that waste heat of the electronic component can be dissipated over the section of the flux conducting device.

Abstract: An ignition coil apparatus for an internal combustion engine does not generate a discharge between a high-voltage terminal and an iron core even if a high-voltage cable falls off from a high-voltage side connector, and the overall height thereof can be reduced. An ignition coil has an iron core disposed in a casing to form a closed magnetic circuit, and primary and secondary coils installed on a part of the iron core. A power switch controls electric power supplied to the primary coil. A low-voltage side connector has a terminal electrically connected with the power switch. A high-voltage side connector has a high-voltage terminal electrically connected with the secondary coil. The casing includes a casing main body accommodating the part of the iron core, the primary and secondary coils and the power switch, and a cover integral with the main body for covering a part of the iron core located outside thereof.

Abstract: A transformer includes at least two magnetically coupled cores with a common axis. The cores have cross sectional configurations transverse to the common axis which are not rectangular. An exciting voltage is to be applied across a first winding provided on one of the cores. A second winding provided on one of the cores includes first and second terminals across which a voltage is to be induced in response to the exciting voltage. A first device provides a relatively higher impedance between the first and second terminals of the second winding. The first device is coupled between the first and second terminals. Third, fourth and fifth windings have respective first and second terminals. The third and fourth windings are wound on one of the cores with a first polarity. The fifth winding is wound on one of the cores with a second polarity opposite to the first polarity.

Abstract: In a stick coil, there is disclosed an ignition coil for an internal combustion engine which can prevent a crack (a collar leak) from being generated due to a thermal stress. In this ignition coil, the structure is made such that a size (L) of a portion which is in parallel to an axial direction of a primary spool (121) in a projection portion (121b) is larger than a size (T) of a portion which is in parallel to an orthogonal direction to the axial direction of the primary spool (121). Accordingly, a frontal projected area of the projection portion (121b) as seen from a flowing direction of a resin becomes small, a resin flow is hard to get out of order at a time when the resin flows through a portion corresponding to the projection portion (121b) at the forming time, and a convoluted void and a weld are hard to be generated.

Abstract: An axially potted progressive wound remote mount ignition coil (axially potted ignition coil) includes a coil case, at least one coil assembly, and a quantity of potting material. Each coil assembly is progressively wound. The coil case includes a coil cavity for each coil assembly, a primary connector, and two secondary connectors for each coil cavity. Each primary coil is connected to the primary connector and an end of each secondary coil is connected to a single secondary connector. A quantity of potting material is poured over the open end of each coil cavity. A second embodiment of the axial potted ignition coil includes a modular coil case, at least one coil assembly, and a quantity of potting material. The modular coil case includes at least one coil tube, a rear end cap and a forward end cap. Each coil assembly is inserted into a respective coil tube.

Abstract: The present invention provides a composite magnetic body containing metallic magnetic powder and thermosetting resin and having a packing ratio of the metallic magnetic powder of 65 vol % to 90 vol % and an electrical resistivity of at least 104 ?·cm. When a coil is embedded in this composite magnetic body, a miniature magnetic element can be obtained that has a high inductance value and is excellent in DC bias characteristics.

Abstract: A circuit board for an ignition coil in an internal combustion engine is provided. The ignition coil is in electrical connection with a control module and a spark plug having a pair of gap posts. The ignition coil includes a primary winding having an electrical current, a secondary winding in electrical connection with the spark plug and configured to induce a second electrical current between the gap posts, and an ionization current sensing integrated circuit configured to generate an ionization signal based on the secondary current between the gap posts. The ignition coil also includes a circuit board having an ionization connection in electrical connection with the secondary winding and with the ionization current sensing integrated circuit.

Abstract: This invention discloses a method for manufacturing an inductor by first press punching a first and a second layer of conductive plates into a first and second coil layers with a first and second inductor lead layers as single integrated layers. The manufacturing process further includes a step of overlapping and connecting the first and second coil layers to form an inductor. In a preferred embodiment, process of manufacturing further includes a step of mixing epoxy to bond with a highly magnetic material and pressure molding the bonding magnetic material around the coil layers to form an inductor.

Abstract: An ignition coil has a connector electrically connected to an external circuit, an igniter for accommodating a switching element adapted to cause a current supplied from the connector to be intermittent, a primary coil portion for generating a predetermined voltage by the intermittent current, a secondary coil portion for stepping up the generated voltage and applying the resulting voltage to an ignition plug, and a resin insulating material which hardens in between the primary coil portion and the secondary coil portion to ensure insulation between the primary coil portion and the secondary coil portion. An outer shell of the igniter is formed of the resin insulating material.

Abstract: A non-contact transformer includes a transformer component provided on the floor of a housing, a printed circuit board on the transformer component, and an empty core space is formed within the transformer component wherein deformation of the housing is prevented through a construction that evacuates residual air from the core space when the core space is filled with resin even though both ends of the core space are covered by lid-like parts. A cylindrical end face at one extremity of the primary transformer component is positioned on the bottom plate of the primary housing opposed to the secondary housing, and the printed circuit board is provided on an opposite cylindrical end face which is at the other extremity of the primary transformer component. A passage is formed between the printed circuit board and the primary transformer component to provide a connecting orifice between a core space of primary transformer component and the space external to the primary transformer component.

Abstract: An ignition apparatus includes a secondary winding spool having a secondary winding wound thereon. The secondary winding includes a low voltage end and a high voltage end that is configured for connection to a spark plug. The secondary winding at the high voltage end is configured in accordance with a predetermined radial thickness profile taken in the direction from the high voltage end towards the low voltage end. The profile is determined as a function of (1) a reflected voltage associated with the spark gap breakdown of the spark plug and (2) an induced voltage due to magnetic flux coupled through a central core. The profile is determined so as to reduce layer-to-layer voltage levels in the secondary winding near the high voltage end. The profile can be wound or can be molded in the secondary spool itself.

Abstract: A rod coil (11) for ignition systems, in particular in the form of an ignition coil in internal combustion engines of motor vehicles, designed for long-term serviceability. The rod coil (11) has a centrally located core (14) as the internal magnetic iron core and, on a housing (13), a yoke (18) made of plastic as the external magnetic iron core. To avoid partial electrical discharges on the rod coil (11), a fill body (22) is provided between the yoke (18) and housing (13) thereby forming an inner, gap-free bond between the yoke (18) and housing (13).

Abstract: The invention is a device and method for eliminating core excitation losses in a distribution transformer when the transformer is not supplying power to loads. The invention consists of sensors, a control circuit, a user interface and a power contactor. The power contactor is connected on the line side of a transformer and is opened or closed automatically based on preprogrammed time or load criteria determined by the control circuit. In one operational mode and when the transformer is disconnected from the line, the control board generates low power pulses at the transformer load connection points in order to “search” for loads. If a load is detected, the transformer is reconnected by way of contactor closure. If the transformer load drops to zero, for a predetermined amount of time, the transformer is again disconnected and the pulsed load search is reestablished.

Abstract: A surface mountable coil is provided with a drum-shaped core including a body portion and raised portion each raised portion having a peripheral surface and an end surface, a winding wire wound around the body portion, an encapsulating member, base electrodes, and terminal electrodes. The encapsulating member exposes some portions of the base electrodes on the peripheral surfaces and substantially the whole base electrodes on the end surfaces. By exposing the portions of the base electrodes on the peripheral surfaces and whole base electrodes on the end surfaces, the contact strength between the base electrodes and the terminal electrodes can be substantially increased.

Abstract: A method of firing magnetic cores includes the steps of attaching a powder to the surface of a plurality of flattened-ring compact bodies made of a magnetic material, arranging the plurality of flattened-ring compact bodies adjacently so that the axes of flattened through-holes of the flattened-ring compact bodies are vertically oriented, and firing the flattened-ring compact bodies while the powder is interposed between the adjacent flattened-ring compact bodies. Alternatively, a method of firing magnetic cores includes the steps of attaching a powder to the surface of a plurality of thin compact bodies made of a magnetic material, vertically arranging the plurality of thin compact bodies adjacently, and firing the thin compact bodies while the powder is interposed between the adjacent thin compact bodies.

Abstract: An electromagnetic device including an outer casing, a shaft rotatably supported by the outer casing, and a motor main body disposed inside the outer casing. The motor main body has a stator and a rotor. The stator has coils constructed by winding conducting wires onto conducting-wire spool portions of first and second bobbins. The coils are embedded in an outer molding, cores are disposed so as to cover the outer molding, and the rotor is secured to the shaft The coils are constituted by first phase and second phase excitation coils formed by winding two of the conducting wires into unifilar windings on the conducting-wire spool portion of the first bobbin. Further, third phase and fourth phase excitation coils are formed by winding two of the conducting wires into unifilar windings on the conducting-wire spool portion of the second bobbin.

Abstract: A magnet system having a magnet coil surrounded by a magnet pot is provided, the magnet coil being electrically connected to contact prongs, an interspace being formed between the outside of the magnet coil and the inside of the magnet pot, in which interspace a free-flowing compound is cast. The magnet coil is surrounded by a thin-walled coil insulating frame on which tubular contact guide elements are integrally molded. The thin-walled coil insulating frame is made of a thermally stable plastic material mixed with mineral fillers.

Abstract: An ignition device for a personal watercraft engine, which allows mounting of a four-cycle engine on the personal watercraft and prevents occurrence of leakage of current. The engine for driving a jet propelling pump is provided in a watercraft body surrounded by a hull and a deck. A spark plug for spark ignition is provided in a cylinder head of the engine, and an integral cap ignition coil having a water-proof structure is water-tightly provided in the cylinder head in such a manner as to be located on the spark plug at an uppermost portion of the engine. A water-escape groove continuous to a recess for receiving a cap is formed in an upper surface of the cylinder head. A bottom surface of the escape groove is formed into a shape tilted downwardly.

Abstract: An ignition coil (1) having a case (2), a core (22) installed in the case, a primary spool (25) disposed substantially coaxially around an outer circumference of the core within the case, a primary coil (26) comprising a wire wound around the primary spool, a secondary spool (23) disposed substantially coaxially around the outer circumference of the core within the case, a secondary coil (24) comprising a wire wound around the secondary spool and a resin insulating material (5) filled within the case, the ignition coil being characterized in that the spool of the primary and the secondary spools which is disposed between the secondary coil and the core and/or which is disposed between the secondary coil and the primary coil comprises a base resin having an adhesive strength to the resin insulating material which is less than that provided by polybutylene terephthalate and an insulation breakdown voltage which exceeds that provided by polyphenylene sulfide.

Abstract: A three-phase transformer is presented comprising a magnetic circuit and three coil block. The magnetic circuit comprises two spaced-apart, parallel, plate-like elements; and three spaced-apart, parallel column-like elementary circuits. Each of the column-like elementary circuits carries the corresponding one of the three coil blocks, and serves for the corresponding one of the three phases. The column-like elementary circuits are substantially perpendicular to the plate-like elements, and are enclosed therebetween such as to form a spatial symmetrical structure about a central axis of the transformer.

Abstract: A non-contact transformer includes a transformer component provided on the floor of a housing, a printed circuit board on the transformer component, and an empty core space is formed within the transformer component wherein deformation of the housing is prevented through a construction that evacuates residual air from the core space when the core space is filled with resin even though both ends of the core space are covered by lid-like parts. A cylindrical end face at one extremity of the primary transformer component is positioned on the bottom plate of the primary housing opposed to the secondary housing, and the printed circuit board is provided on an opposite cylindrical end face which is at the other extremity of the primary transformer component. A passage is formed between the printed circuit board and the primary transformer component to provide a connecting orifice between a core space of primary transformer component and the space external to the primary transformer component.

Abstract: A pencil ignition coil assembly module (40) that has a frusto-conically tapered core (46) and encapsulation (280) surrounding the side of the core. Features (216, 230, 234) center the core to a bobbin 48. A retainer (240, 240A) captures the core within the bobbin.

Abstract: A coil-embedded dust core and a method for manufacturing the coil-embedded dust core are provided. The coil-embedded dust core comprises a coil formed from a flat conductor wound in a coil configuration, and a green body consisting of insulating material-coated ferromagnetic metal particles. This results in a coil-embedded dust core more compact in size but with larger inductance. A rectangular wire can be used as the flat conductor. In addition, parts of the coil may function as terminal sections. In this case, the terminal sections of the coil may be formed wider than other part of the coil. The coil-embedded dust core is less prone to joint failures between a coil and terminal sections and to insulation failures of the coil and the terminal section with respect to the magnetic powder. The coil-embedded dust core is more compact while achieving larger inductance.

Abstract: An independent ignition type ignition coil for an internal combustion engine, comprising, arranged concentrically in a coil case (6) and with the innermost one mentioned first, a center core (1), a secondary coil (3) wound on a secondary bobbin (2) and a primary coil (5) wound on a primary bobbin (4), with epoxy resin (8) and soft epoxy (17) filled between these component members, wherein a coating is formed on the outer surface of the primary coil (5) so as to facilitate the separation from the epoxy resin (8) and the presence of this separation portion (50) between the primary coil (5) and the resin and in an interlayer of the primary coil (5) can reduce from a thermal stress produced within the secondary bobbin (2) a stress which is produced in the secondary bobbin by a heat contraction difference between the primary coil (5) and the secondary bobbin, thereby reducing the thermal stress of the secondary bobbin of the independent type ignition coil exposed to a rigorous temperature environment to prevent bo

Abstract: A coil module applied in a transformer. The coil module includes at least one conductive wire and an insulating encapsulator. A portion of the conductive wire is wound into coils of a certain loop number. The coils are encapsulated by the insulating encapsulator. A metal core is provided when manufacturing a transformer. Desired coil modules are selected and installed onto the transformer so as to surround the metal core of the transformer. The coil modules are thus connected in series or in parallel for forming a desired specification of the transformer.

Abstract: A method of obtaining a module including at least one inductive winding made up of one or more conductive tracks on a printed circuit film support on which the tracks form turns which are combined to form a winding or a plurality of parallel and/or coaxial windings.

Abstract: An ignition coil device has a secondary spool, a secondary coil wound around the secondary spool, an insulating resin material that is filled into spaces between the secondary windings, a primary spool, a primary coil wound around the primary spool, a connector that is arranged on one end side in an axial direction of these parts and has a connector terminal electrically connected to the primary coil and the secondary coil, and a resin insulting material for connector that is filled into the connector. The base material of the coil insulating resin material is the same as or different from the base material of the connector insulating resin material.

Abstract: A conductive member is disposed between a secondary spool and a high tension terminal to shield the wire connecting the secondary coil and the high tension terminal. The conductive member has a wide surface facing the low tension components to moderate the electric field strength around low tension components, thereby preventing treeings from growing in the insulating filler of the ignition coil.

Abstract: An electrical assembly that prevents contaminants from migrating to the coil windings within an encapsulant forming the main housing through the use of a sealing assembly located within an over-molded, thermoplastic encapsulant. Before over-molding, an elastomeric seal is installed on each lead wire to be sealed, and this wire/seal subassembly is then inserted into a seal housing made from the same basic thermoplastic as the encapsulant forming the housing. The seal housing has one or more continuous ribs, with sharp edges, that circumvent the outer surface of the seal housing. During over-molding to form the main housing, the molten encapsulant surrounds the seal housing and melts the tips of the ribs. Upon cooling, the (no thermoplastic solidifies and the encapsulant bonds to the seal housing along each of its ribs.

Abstract: Method for introducing encapsulating material into an ignition coil including a primary winding, a secondary winding and a secondary spool is provided. The method allows providing a fluid-directing device at a first end of the secondary spool. The method further allows providing flow communication between the fluid-directing device and a first channel defined between the outer diameter of the primary winding and the inner diameter of the secondary spool. Flow communication is provided between the first channel and a second channel at a distal end from the first end. The second channel defined between the outer diameter of the secondary winding and the housing of the ignition coil. Encapsulating material (either pressurized or non-pressurized) is introduced through the fluid-directing device for generally downwardly flow into the first channel.

Abstract: An operation of connecting primary coils and a wiring module of an ignition apparatus for an internal combustion engine is carried out smoothly. The ignition apparatus includes a casing (8), closed magnetic circuit cores (2), primary coils (4) each having primary coil connector terminals (40a, 40b) at their opposite ends, respectively, and secondary coils (6) having secondary coil connector terminals (6a). A wiring module (9) is composed of a plurality of wires integrally formed with each other through a resin for supplying current to the primary coils (4). A resin portion (11) is filled into the casing (8) to fixedly attach transformers (1A, 1B, 1C) to the casing (8). A positioning element (9c, 40c) is arranged between the primary coils (4) and the wiring module (9) to position the relative positions of the primary coil connector terminals (40a, 40b) and module connector terminals (10a, 10c).

Abstract: An ignition coil has a case and a central core placed in the case. A secondary spool is wound with a secondary coil and placed outside the central core in the case. A cylindrical primary spool is wound with a primary coil and placed outside the secondary spool in the case. A resin insulator is filled in the case to maintain the insulation between each member. Air layer is partitioned in at least one of a gap between the central core and the secondary spool and a gap between the primary spool and the case.

Abstract: A system for converting a DC input voltage to a DC output voltage includes at least one integrated circuit die electrically coupled to a leadframe. An inductor is also coupled to the leadframe and electrically coupled to the integrated circuit die. An inductor casing generally surrounds the inductor, and a molding encapsulates the integrated circuit die, a portion of the leadframe, and a portion of the inductor. The integrated circuit die and the inductor are operable to receive the direct current input voltage and to convert the direct current input voltage to the direct current output voltage.

Abstract: A sleeved case design which provides variable increases in creepage distance for toroidal inductors mounted in a case for automatic insertion into circuit boards by means of sleeves protruding upward into the case from mounting holes in the case floor. A sleeve surrounds the hole so that the shortest distance from the case floor at the point of closest contact with the inductor along a case surface to the hole is up the outside of the sleeve and down the inside of the sleeve. The wire leads of the secondary for the inductor are routed through the sleeves.

Abstract: A transformer with an associated heat-dissipating plastic element is provided. The transformer includes a hollow main body, a core, a coil and a heat-dissipating plastic element. The core is installed inside the hollow main body while the coil wraps around the core. The heat-dissipating plastic element is also installed inside the hollow main body. The heat-dissipating plastic element encloses the core and the coil. Alternatively, the heat-dissipating plastic element encloses the hollow main body, the core and the coil so that heat generated by the coil may be directly conducted away to the exterior through the heat-dissipating plastic element.

Abstract: An ignition apparatus includes a central core extending along a main axis, and a primary winding disposed radially outwardly thereof. The ignition apparatus further includes a secondary winding. The primary winding has a greater axial length than the secondary winding, this additional axial length being implemented on the low-voltage axial end of the ignition apparatus, relative to the main axis. The extended primary winding provides an increased leakage inductance spike, which may be used by an ion sense system to (i) obtain increased bias voltages, and, (ii) increase the effective turns ratio, thereby reducing the amount of wire required for the secondary winding.

Abstract: An insulated electrical coil is disclosed and is formed from a plurality of turns of coil, each having a cured body of resinous insulation applied to each turn of coil. The insulation is formed from a cured resinous composition of epoxy-anhydride resin that has been prereacted with an antioxidant oligomer selected from the group consisting of organophosphorus compounds, sterically-hindered alkylated phenolics, alkyl and aryl thio-esters, alkyl and aryl thio-phosphites, thiazoles, lactones, hydroxylamines, and maleimides.

Abstract: An ignition coil according to the invention is an ignition coil having a case and a coil portion accommodated in the case. The case comprises a base resin whose dielectric breakdown voltage exceeds that of polyphenylene sulfide and whose spiral flow length exceeds that of polybutyrene terphthalate. As the base resin has a high fluidity, there is only a limited risk that a defect such as a weld line is caused when molding a thin case. In addition, while the thickness of the case and the electrical insulation properties are in proportion to each other, the case comprising the base resin can ensure sufficient electrical insulation properties even if the case is formed thin.

Abstract: An ignition coil includes a housing which contains a central core portion, an inner spool having a first winding, and an outer spool having a second winding. The inner spool extends outward of the central core portion. The outer spool extends outward of the inner spool. A locating member includes a locating rib adjacent to an upper portion of the central core portion. The locating rib is in a gap between the inner spool and the central core portion, and locates the inner spool and the central core portion relative to each other. Insulating resin injected into the housing provides insulation among parts in the housing. At least one of the inner spool and the locating member has a void-escape passage which connects the gap and an outside of the inner spool with each other, and which allows a void to escape from the injected insulating resin in the gap.

Abstract: An ignition coil for an internal combustion engine is mainly made up of a transformer part and a control circuit part and a connecting part, and the transformer part is made up of a iron core which forms an open magnetic path, magnets, a secondary spool, a secondary coil, a primary spool and a primary coil. By respectively setting the cross-sectional area SC of the iron core between 39 to 54 mm2, the ratio of the cross-sectional area SM of the magnets with the cross-sectional area SC of the iron core in the 0.7 to 1.4 range, the ratio of the axial direction length LC of the iron core with the winding width L of the primary and secondary coils in the 0.9 to 1.2 range, and the winding width L in the 50 to 90 mm range, the primary energy produced in the primary coil can be increased without increasing the external diameter A of the case.

Abstract: Preparation is made of alloy powder comprising 3.0-8.0 wt % Si, 0.1-1.0 wt % O, 0-2.0 wt % (0 being exclusive) of at least one element selected from Mn, Al, V, Cr, and Ti, and balance Fe and having a particle size substantially equal to 150 &mgr;m or less. A binder is mixed with the alloy powder to form a mixture. The mixture is compaction-formed by the use of a die. Thus, a powder core is obtained which has a 20 kHz a.c. permeability equal to 20 or more under an applied d.c. magnetic field of 12000 A/m, a core loss characteristic of 1000 kW/m3 under the conditions of 20 kHz and 0.1 T, saturation magnetization of 10000 G or more, and coercive force of 3.0 Oe or less.

Abstract: A method for forming a resin molding on a coil of a transformer is disclosed. The method comprises the steps of inserting a coil into an auxiliary spacing apparatus, inserting the auxiliary spacing apparatus into a mold, and forming a resin molding for the auxiliary spacing apparatus with the coil by putting a resin into the mold. According to the methods, the coil is not damaged and a resin molding is formed with a uniform thickness.