Abstract: A three-phase transformer and a method of its manufacture are presented. The transformer comprises a magnetic circuit and three coil blocks. 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. Each of the column-like elementary circuits is substantially a toroid in the form of a multi-layer structure formed by winding a predetermined number N of packages of magnetic strips about a central axis of the toroid, each package being composed of a predetermined number n of layers formed by n strips placed on top of each other.

Abstract: Non-linear inductor(s) are used to reduce the percent total harmonic distortion of the harmonics in the line currents in the input side rectifier system of an ac drive system. Several constructions for the non-linear inductor(s) are described. The non-linear inductor(s) may be constructed from E and I laminations. The gap depends on the construction of the middle leg of the E laminations and may have a step with a constant spacing or a variable spacing which depends on the stacking of the laminations. Alternatively the non-linear inductor(s) may be constructed from a toriodal core that either has a step gap or a variable type gap.

Abstract: A reactor in which two first cores 1 made of lamination and I-shaped and two second cores 2 made of lamination and I-shaped are disposed such that the two first cores are parallel to each other, the two second cores are parallel to each other and that the two second cores having respective coils 4 therearound are perpendicular to the two first cores, thereby forming a rectagular shape, wherein there are provided a first spacer 10 and a second spacer 20, which have on their respective outward side faces two protrusions 13, 23 for positioning each first core and two other protrusions 14, 15 for holding longer sides of each first core with one thereof having at its tip end an engaging mechanism to secure each first core, and which have on their respective inward side faces four protrusions 17, 27 for positioning two neighboring corners of the respective second cores and an elevated portions 16, 26 provided between the four protrusions and elevated in a direction perpendicular to the length of the first cores.

Abstract: An inductor of the invention is obtained by forming conductors of a desired shape on bendable plate type support members, providing a slit in one end of each of the conductors, and a claw on the other end of each of the conductors, bending the plate type support members, engaging the slits and claws with each other so as to form windings on the support members and openings therein, and inserting magnetic cores through the openings.

Abstract: A controlled ferroresonant constant current source includes a ferromagnetic core accommodating the below-mentioned inductors. An input coil is to be connected to an alternating voltage source. An output coil is inductively coupled to the input coil, and is to be connected to a load. A control coil is inductively coupled to the output coil, and is to be connected to a switch for regulating the current output of the constant current source. A first capacitor coil is inductively coupled to the output coil, and is to be connected to a capacitor to provide a first resonant sub-circuit having maximum gain. A second capacitor coil is inductively coupled to the control inductor, and is to be connected to the capacitor to provide a second resonant sub-circuit to control resonant gain.

Abstract: A reactor in which two first cores 1 made of lamination and I-shaped and two second cores 2 made of lamination and I-shaped are disposed such that the two first cores are parallel to each other, the two second cores are parallel to each other and that the two second cores having respective coils 4 therearound are perpendicular to the two first cores, thereby forming a rectagular shape, wherein there are provided a first spacer 10 and a second spacer 20, which have on their respective outward side faces two protrusions 13, 23 for positioning each first core and two other protrusions 14, 15 for holding longer sides of each first core with one thereof having at its tip end an engaging mechanism to secure each first core, and which have on their respective inward side faces four protrusions 17, 27 for positioning two neighboring corners of the respective second cores and an elevated portions 16, 26 provided between the four protrusions and elevated in a direction perpendicular to the length of the first cores.

Abstract: An inductor of the invention is obtained by forming conductors 21 of a desired shape on bendable plate type support members 20, providing a slit 24 in one end of each of the conductors 21, and a claw 25 on the other end of each of the conductors, bending the plate type support members 20, engaging the slits and claws with each other so as to form windings 12 on the support members and openings 28 therein, and inserting magnetic cores 11 through the openings.

Abstract: An impedance matching device provided between a high-frequency generator and a load device matches an impedance of the high-frequency generator with an impedance of the load device and includes at least a coupled circuit which comprises a core, and a main winding and a control winding which are wound around the core. The coupled circuit changes an impedance of the impedance matching device by changing an inductance value of the main winding which depends on a magnitude of direct current flowing in the control winding.

Abstract: A single-phase three-wire type transformer which forms secondary coils by duplex coils winding two conductors in parallel according to the division intersection connection and can reduce currents circulating inside of a circuit of the transformer, thereby reducing the loss in the transformer. Coils A and B are formed in two opposing locations of a core (1). The coils A and B are configured so that two secondary coils and a primary coil are overlapped and wound in sequence from the inside of the core (1) in three layers, respectively. Each of the secondary coils provided by winding two conductors of small diameter in parallel condition on the core (1). One duplex coil connects the two parallel winding conductors in series with the other duplex coil, i.e.

Abstract: A ferroresonant transformer includes a three-legged magnetic core. The core includes a center leg, and first and second flanking legs. Each of the center and flanking legs have respective first and second longitudinal ends. The first flanking leg is positioned at an opposite side of the center leg relative to the second flanking leg. A first end-connecting portion magnetically couples the first ends of the center and flanking legs, and a second end-connecting portion magnetically couples the second ends of the center and flanking legs. The center leg defines a substantially non-magnetic space, such as an air gap, along a magnetic flux path extending along the center leg from the first end-connecting portion to the second end-connecting portion in order to reduce the total harmonic distortion of the ferroresonant transformer.

Abstract: An inductor (100) optimized for surface-mount vacuum-pickup automated circuit assembly eliminates the expense of an inductor housing. The inductor has a hollow rectangular ferrite core (101) and a winding defined by a stripline (102) deposited on the core surface. Winding ends are formed by conductive vias (103) in the core that open onto the core surface, where they connect and mount the inductor to a circuit board (150). A flat sheet (104) adhered to one face of the core provides a surface for vacuum pickup and for labeling of the inductor. The core of a passively tuneable inductor (200) defines multiple unconnected winding segments (102-103). Segment ends mount the inductor to the circuit board and connect the segments to circuit board striplines (254) that are laid out in a pattern to interconnect a number of the segments into a winding. The inductor is tuned by changing the stripline layout and thereby varying the number of interconnected segments.

Abstract: A choke coil for preventing harmonic distortions, used with home-use and industrial electronic apparatuses, is designed to reduce the apparatus size, reduce leakage fluxes and realize superior high-frequency characteristics. In order to achieve this object, there is provided a choke coil comprising a first magnetic core and a second magnetic core making up a closed magnetic circuit or an open magnetic circuit, a first coil, a second coil and a third coil, wherein the first coil is wound on the first magnetic core, the second coil is wound on the second magnetic core, and further the third coil is wound in such a manner as to cover the first magnetic core and the second magnetic core, and an inductance value required for preventing harmonic distortions is secured by the magnetic circuit configuration. At the same time, the function of a common-mode choke coil is provided to increase a coupling coefficient and reduce the system size and leakage fluxes.

Abstract: Two vertical, parallel, horizontally spaced signal coils are connected in series but in opposite phase across an a.c. source. Thus a buried conductor located centrally beneath the coils experiences an alternating magnetic field whose strength is due to the addition of the fields induced by the two coils. The field strength may be further enhanced by one or more of: providing a ferromagnetic flux diverter between the upper ends of the coils; placing a conductive nonmagnetic screen between them; connecting a tuning capacitor in parallel with the coils; or providing a tuning circuit having series-connected secondary coils which are flux-linked to respective signal coils and are in parallel with a capacitor. There may be a switch arrangement for switching the signal coils to in-phase connection, for use when they are oriented horizontally.

Abstract: For use with a transformer unit comprising a main housing accommodating a transformer, a coil case is provided which encloses a high-voltage coil and the magnetic core section around which said coil is mounted. Only the interior space of the coil case is filled with insulating compound.

Abstract: An EMC filter for a balanced multi-wired telecommunication line has an oblong closed magnetic path core 50 having at least one first core arm 50a with a first length and second core arms 50b with a second length which is equal to or shorter than the first length, and a plurality of coils 51 constituted by at least one pair of wires. The at least one first core arm 50a and the second core arms 50b constitute a closed magnetic path. The wires of each pair are closely positioned each other and wound around the at least one first core arm 50a so as to produce magnetic fluxes in the first core arm 50a flowing toward the same direction when a common-mode current flows through the wires. Each of the coils 51 has a signal input end and a signal output end, and the wires run in a one-way direction from the signal input ends to the signal output ends, respectively.

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 indirect feedback type flyback converter that compares favorably with the direct feedback type flyback converter in controllability of secondary output voltage, wherein the converter is arranged so that a switching signal, which is induced in a secondary winding when a direct current input voltage, applied to a primary winding, is turned ON and OFF by a switching element, is smoothed by rectification and fed to a load and that an output voltage is detected using a switching signal induced in an auxiliary winding to transmit a control signal to the switching element for the purpose of stabilizing the output voltage; wherein the primary, secondary and auxiliary windings are formed on respective coil formation surfaces of a coil laminate as convoluted shaped conductor patterns disposed between a core hole at the center of the pattern and the border of the coil formation surface, with the auxiliary winding being disposed to be near the border of the coil formation surface.

Abstract: An integrated magnetic exploding foil initiator fire set includes a DC-DC converter with a first transformer, a triggering mechanism with a second transformer, and an integrated magnetic structure for the respective transformers. Inductive interference is minimized in the respective transformers by the construction and placement of the transformer windings. The use of planar magnetic core material and flexprint or printed circuit technologies for the windings reduces the cost and weight of the structure and provides a compact construction. Thus, the triggering mechanism provides higher energy and voltage output and eliminate the need for expensive spark-gap switches.

Abstract: Two sets of a combination of an iron core formed of laminated strip-shaped electromagnetic steel plates and a coil are arranged in parallel, and these are abutted via core gap spacers against two iron cores formed of laminated trapezoidal electromagnetic steel plates, so that a square-shaped magnetic path is formed. Two outside iron cores of the four iron cores are coupled and fixed with metal fittings. With such an arrangement, the coil is divided into two, with increased surface areas of the coils and therefore an improved cooling characteristic. Further, since the electromagnetic steel plates used for the iron cores can be formed into simple shapes, electromagnetic steel plates of various sizes can be easily manufactured, so that iron cores of optimum dimensions can be provided, optionally depending on the type of the reactor.

Abstract: A multi-tapped surface mount inductor (300) providing high quality factor (Q) and high inductance is capable of being surface mounted on any of its four sides. An inner substrate layer(s) (322) is provided with metallized patterns (328, 332) and vias (336) to form a multi-turn coil. The inner substrate layer (322) is then sandwiched between first and second outer substrate layers (324, 326) to form a six sided structure. Tapped element(s) (304) can be tapped off the multi-turn coil in increments of a quarter turn or less to provide a multi-tapped surface mount inductor capable of being mounted an any of its' four side surfaces (310, 312, 314, 316). When tapped element(s) (204) are tapped symmetrically between the input/output ends (214, 216), the surface mount inductor (200) may interchange its' input/output ends (214, 216) making the component surface mountable in eight different positions.

Abstract: Main and supplemental windings are combined in a toroidal inductor to subntially nullify Lorentz Forces on the main winding and the magnetic field thereof which passes externally from the inductor.

Abstract: The internal and/or external magnetic fields of a coil are nullified to ad structurally detrimental Lorentz Forces and/or environmentally hazardous magnetic fields, in accordance with preestablished design objectives.

Abstract: A transformer comprising a core, a plurality of primary coils and a plurality of secondary coils, the core having three sections arranged in a generally triangular configuration forming three vertices, the coils being disposed on the core about respective vertices, each of the core sections having at least one mitered side abutting a mitered side of an adjacent core section.

Abstract: An air-coupled current transformer is provided with a primary current conductor and two secondary coils connected such that the emf induced in each coil by an external disturbing magnetic flux is subtractive, whereas the emf induced by the current in the primary is additive. Two ferromagnetic core pieces enhance the rejection of the emf induced by the disturbing flux. Ceramic spacers are inserted into air gaps between the core pieces for maintaining the gaps fixed to keep the scale factor of the transformer independent of temperature.

Abstract: A transformer designed for 1:N voltage transformation (where 1:N may be any rational number) at high frequencies (such as over 7 megahertz) can achieve acceptable frequency response and attendant improved values of signal attenuation and signal distortion by physically separating two or more sets of electrically tightly coupled windings and connecting one winding of different sets in parallel and the other winding of the same sets in series. This interconnection of windings to achieve a 1:N transformation ratio reduces the negative effects of the interwinding capacitance thereby providing the improved frequency response.

Abstract: Plane sheets which have the same shape as the magnetic circuit and are relatively movable along their contact surface are arranged in a stack. The stack is grasped and part of the circuit is bent out of alignment with the plane of the sheets to enable a coil to be placed on a portion of the circuit which is next to the air gap, whereafter said part is bent back into alignment with said sheets.

Abstract: A common mode choke coil having a couple of cores shaped like U and four coils wound around legs of the cores. The cores having coils around their legs are butt-jointed at the end, and coils wound around each couple of butted legs cause magnetic fluxes in mutually opposite directions.

Abstract: A current transformer comprising a primary conductor means 20, secondary conductor means in the form of a first and second coil 21, 22 connected to ensure common-mode rejection of emf induced by external disturbing magnetic fields, and magnetic coupling means defined by first and second magnetic plates 23, 24 and first and second ferrite elements 25, 26 arranged within the first and second coils 21, 22, the elements 25, 26 contacting and physically separating the first and second plates 23, 24, thereby defining a closed magnetic circuit with the plates.

Abstract: A manner of using a plurality of transformers having cylindrical cores such that operation of the transformers at high frequencies allows the cores of the transformers to be disposed parallel to each other and in relatively close proximity without substantial interference.

Abstract: An integrated magnetic filter inductor having series and common mode windings includes a magnetic core (44) having a first leg (46), a second leg (48), and a third leg (50). The first leg (46) is connected to the second leg (48) with bridging structures (52) and (54). In a similar manner, the third leg (50) is connected to the second leg (48) with bridging structures (56) and (58). A common mode winding (64) is wound about the bridging structure (52) with a given dot orientation. A common mode winding (66) is wound about the other bridging structure (54) with the same dot polarity. Current flowing into the dot terminal of the common mode winding (64) and out of the dot terminal of the common mode winding (66) result in a net zero magnetic flux induced in the magnetic structure (44). A common mode winding (68) is wound about the bridging structure (56) with a predetermined dot polarity. A common mode winding (70) is wound about the other bridging structure (58) with the same dot polarity.

Abstract: An integrated EMI/RFI Filter Magnetic has differential and common mode inductors wound about an I-Core. The I-Core is juxtaposed with an E-Core, with the end surfaces of the E-Core legs facing the I-Core. The magnetic has a substantially closed magnetic path for the differential inductors and the common mode inductors.

Abstract: A breaker apparatus for preventing a power line carrier frequency from moving along a power supply lead. The breaker comprises a core member with a first leg, a second leg and a third leg where each leg extends between a top section and a bottom section of the core member. The top section and a first leg portion define a top core section and the bottom and a second leg portion define a bottom core section. The top and bottom core sections are separate sections. A first power supply line enters the core member from one of the sides of the core member and coils around the first leg of the core member and exits from the same side as entering the core member to form a first coil winding. A second power supply line enters the core member from the other remaining of the sides of the core member and winds around the third leg of the core member and exits from the same side as entering the core member to form a second coil winding.

Abstract: The invention discloses a non-contact way to provide electrical power and two-way digital communications between a host computer and its peripheral modules, such as IC memory cards, modems, and A/D converters. A special magnetic core is employed to provide efficient transfer of both large amounts of electrical power and high speed digital communications through transformer action. Peripheral modules requiring different power supply voltages or different data voltage levels can be accommodated and intermixed with modules of other types in the same host system. The mechanical design of the connector includes detent structure to align the assembly in three dimensions, both upon mating, and under mechanical environmental stress conditions during operation. The magnetic core has both power supply and data windings; the data winding has sections of opposite polarity so that the power supply signal imposed on the data winding cancels itself.

Abstract: The magnetic core of the transformer is an E--E shaped core. The primary winding of the transformer is divided into three substantially identical planar coils, each coil being wound on one of the three separate core posts. The coils are wired in series such that a current in the primary winding will induce substantially identical magnetic fluxes in the two outer core posts, and an opposite flux in the center post. The secondary of the transformer is formed by a contact plate and a conductor frame which provide conducting paths through the window regions of the E--E core. The bottom of the core is mounted in a recess in the conductor frame. Positioned within in the conductor frame are four rectifiers which make electrical connections to the secondary contact plate. When the transformer delivers power, the voltage on the primary winding will be divided 1/4 on each of the outer coils and 1/2 on the center coil post. During this time only two of the rectifiers will be conducting current.

Abstract: A summing transformer for a star-delta inverter having a single secondary winding for each group of primary windings for use in inverting variable frequency AC power into constant frequency AC power, the transformer comprising a plurality of core elements having principal legs on which primary windings are wound and secondary legs extending from said principal legs establishing flux paths, the legs of each core element defining apertures through which a single winding is magnetically linked to a group of primary windings.

Abstract: A core for an integrated magnetic power converter includes a continuous magnetic structure having first and second legs and a magnetic flux conducting path therebetween. A primary winding is disposed on the first leg. A first secondary winding is disposed on the first leg. A second secondary winding is disposed on the second leg. The first leg has a cross-sectional area which is greater than the cross-sectional area of the second leg.

Abstract: A power conditioner for AC power lines has a choke and capacitor coupled in series across the power lines. The choke comprises a coil terminating in a line, with the line looped back through the coil. The power lines are thereby balanced to provide greater operating efficiency. Capacitors and transient suppressors (e.g., varistors) are used for transient suppression and power factor correction.

Abstract: A coil assembly for use in an inductively powered transponder including a primary coil and a secondary coil wrapped around the same coil forming ferrite rod. The primary coil's leads are left floating while the secondary coil's leads are connected to the integrated identification circuit of the transponder. There are approximately three times as many turns to the primary coil as there are turns to the secondary coil. The primary coil is configured to self resonate at the operating frequency of the identification circuit when brought within range of an interrogator's magnetic field, thereby creating a voltage across the primary coil having a high source impedance.

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 high frequency transformer is made on a magnetic circuit which can be of a generally square shape. The secondary windings are made on printed circuit plates, separated by insulators and traversed perpendicularly by the core or cores of the magnetic circuit. The primary winding can be wound directly on such a core. The transformer is applicable in particular to high frequency very high voltage power supplies, in particular of the type termed "flyback" power supplies.

Abstract: A multi-magnetic field plural core transformer having two or more non-contacting core loops of ferromagnetic material, each core loop including first and second portions, the first portion of each core loop being positioned adjacent to the first portions of the other core loops with each core loop first portion encircled by a primary winding, and the transformer having means for electrically interconnecting the primary windings in circuit with one another, and at least one secondary winding passing through all core loops.

Abstract: Disclosed is a bar or conductor constituted by a plurality of strands disposed in a slot and extending outward from the opposite ends of the slot with each of the strands being substantially bisymmetrically vertically slanted so as to be transposed in the vicinity of a longitudinally central portion of the slot-inside bar portion. Each of the strands being transposed such that the respective strand arrangements at the opposite ends of the slot-outside bar end portions are reversed with respect to each other, with the total number of transposed portions of all the strands is less than three times the number of the strands.

Abstract: An AC line filter in which a pair of windings are wound in an opposite dition to each other and are provided at opposing locations on a main core that forms a closed magnetic path. At least one auxiliary core which forms a shorter magnetic path than the main core is positioned adjacent the main core. The auxiliary core has at low frequency region an effective permeability higher than that of the main core. A portion of each of the pair of windings being provided in such a way that the portion is a concentrated winding which surrounds both the main core and the auxiliary core simultaneously.

Abstract: A transformer structure includes two planar primary windings in a single plane with one primary winding on each leg of a core. The primary windings are connected in series or in parallel. The secondary structure includes a planar conductor structure about the core. A conductor passes through the core and makes electrical connection to the planar conductor through diode rectifiers. An anti-phase embodiment has dual primary circuits and dual cores with a combined secondary structure. Both plate-form and circuit card form embodiments are disclosed.

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 electromagnetic shield for electromagnetic apparatus comprises a plurality of shield coils (2-7) wound intermittently on a looped magnetic core (11). Same polarity terminals of the shield coils are connected to form current paths which prevent external fluxes .phi..sub.1, .phi..sub.2 from entering into the core.

Abstract: An AC power/step-down transformer suitable for use in switchgear for controlling electrical apparatus such as an indicator lamp has low core cost and permits economical assembly, as no interleaving of laminations is required. Its magnetic circuit comprises simple rectangular coil core assemblies whose ends are either fitted into holes in upper and lower plate assemblies or abutted against them. There are two primary and two secondary coil core assemblies, spaced apart to permit pushrods to pass between them for actuation of a back-mounted switch. A primary winding is placed around both of the primary coil core assemblies, and a secondary winding is placed around both of the secondary coil core assemblies.

Abstract: A magnetic head integrally assembled with a step-up transformer. The magnetic head portion is formed on a lower substrate by a thin film technology and the number of turns of the signal winding is 1 or a value near 1. The transformer portion mainly comprises a transformer magnetic circuit which is formed by the lower substrate and upper substrate. A one-turn primary coil of a thin film formed over the lower substrate and a secondary coil by a bulk wire are arranged so as to couple inductively with each other through the transformer magnetic circuit. The signal winding and the primary coil winding are formed by the same thin film process. The head portion and the transformer portion thus are arranged very closely and hence coupled with very little transfer loss of signal.

Abstract: A rotation detecting apparatus disposed on the outer periphery of a compressor including an airtight casing containing a rotor. The rotation detecting apparatus is constituted by plural magnetism detecting elements attached to the outer periphery of the airtight casing of the compressor in correspondence with a rotational orbit of a magnet disposed on the rotor within the airtight casing, such plural magnetism detecting elements each having a core made up of at least one amorphous alloy wire and a coil wound around the outer periphery of the core.

Abstract: A high-power pulse transformer for short, high-voltage and/or high-current pulses includes:a base plate in a container, an insulating, cooling dielectric liquid with a given heat transfer coefficient in the container;at least one magnet core on the base plate with self-enclosed magnet legs around a central window and wide sides with axes normal to the axis of the window;at least an undervoltage and an overvoltage winding in the liquid wrapped in each other around parts of the magnet core immersed in the liquid and linked to the magnet core and to each other, the windings including turns of substantially mutually doubly-wound electrically insulated metallic conductors having winding ends disposed in leadthroughs in the container walls, the conductors having surfaces with a heat transfer coefficient higher than that of the dielectric liquid;the turns of each winding being self-supported and spaced apart from the turns of the other winding by a first minimum spacing and spaced from the magnet core by a second mi