Abstract: A laminated core according to an aspect of the present invention includes a plurality of electrical steel sheets stacked to each other; and a plurality of adhesion parts that are provided between the electrical steel sheets adjacent to each other in a stacking direction and adhere the electrical steel sheets to each other, in which, when viewed in the stacking direction, the plurality of adhesion parts are formed in a belt shape that extends in a first direction, the plurality of adhesion parts are arranged in a second direction orthogonal to the first direction, and an angle formed by the first direction and a rolling direction of the electrical steel sheet is 30° or more and 90° or less.

Abstract: An apparatus for fabricating non-planar coils includes a rotating table driven by a first motor; a wire approach height adjustment arm driven by a second motor; and a synchronization module configured such that a wire traversing from the height adjustment arm to a bobbin on the rotating table passes into a non-planar groove cut in the bobbin without damaging the wire. Performing magnetic resonance (MR) measurements includes a plurality of coil units configured for generating a gradient or shim magnetic field. The coil unit includes a plurality of coil windings, and each coil winding is separated longitudinally from an adjacent coil winding. A single pair of electrically conducting leads is configured to cause current to flow through all of the plurality of coil windings in the coil unit. Techniques include methods to fabricate and operate the apparatus.

Abstract: A test and measurement instrument for determining magnetic core losses of a device under test during in circuit operation. The test and measurement instrument receives a primary current signal from a primary winding of a device under test and receives a primary voltage signal measured across a magnetic core of the device under test. Based on the primary electric current signal and the primary voltage signal, the test and measurement instrument determines a magnetic loss of the device under test. In some examples, the test and measurement instrument can use primary and secondary voltage and current inputs to determine the magnetic loss of the device under test. The magnetic loss of the device under test can be displayed on a display of the test and measurement instrument. The magnetic loss can include a total magnetic loss, a hysteresis loss, a copper loss, and/or other losses.

Abstract: A circuit is provided that comprises a transformer having a first coil, which is arranged on a substrate, a second coil, which is arranged above the first coil on the substrate, and a dielectric between the first coil and the second coil. The circuit furthermore comprises a resonant circuit, which is couplable to the first coil and/or the second coil to form a resonant loop, wherein a measure of a characteristic frequency of the resonant loop and/or a measure of a power consumption of the resonant loop is able to be tapped off at an output of the resonant circuit. A corresponding method is also provided.

Abstract: An electromagnetic induction device comprising a magnetic core having a limb and at least one winding wound around the limb is presented. The winding comprises: an electrical conductor forming a plurality of radially overlapping layers around an axis; an electrically insulating material positioned between the radially overlapping layers of the electrical conductor; at least one magnetic material end-fill positioned at at least one axial end of the winding in electrical in contact with the layers of the electrical conductor so to be at the same electrical potential with the latter.

Abstract: The present disclosure provides a common or differential mode inductor for connection to a printed circuit board. The inductor includes a core, a first coil including a first insulated wire wound with a number of turns around the core, and a supporting device for supporting the core and the first coil. The supporting device includes a base element having a PCB contacting surface, and a first alignment element having a proximal end connected to the base element and a distal end provided at a distance from the PCB contacting surface, wherein the distal end is defining an alignment plane. The core has a first end plane facing the alignment plane and a second end plane, wherein the first end plane is facing the alignment plane. The second end plane is facing the base element.

Abstract: A coil component includes a core including a winding core portion, a first wire, a second wire, a third wire, and a fourth wire that are wound around the winding core portion. A winding portion is formed by winding the respective first to fourth wires around the winding core portion. The winding portion includes a twisted wire portion in which the first wire, the second wire, the third wire, and the fourth wire are collectively twisted.

Abstract: The present disclosure relates to an electrical insulator, for an inductive device filled with an electrically insulating cooling fluid. The insulator defines a plurality of internal channels for allowing the fluid to flow there through to improve circulation of the fluid within the inductive device.

Abstract: A reactor includes a coil that has unit coils. Spacers are disposed in (i) at least one of spaces between the unit coils adjacent to each other in the central axis direction and (ii) a space between each of the support frames and the unit coil. Bolts penetrate the support frame and the spacers, and the spacers are fixed to the bolts The bolts include fitting portions to be fitted to one of the spacers on a notch or a through hole formed in a projection part of the spacer.

Abstract: A linear variable differential transformer includes: a moving portion having a shape extending in a direction of an axial line; a bobbin including a through hole formed such that the moving portion is movable in the direction of the axial line, an outer circumferential surface of the bobbin having a shape inclined symmetrically with respect to a center line thereof based on the direction of the axial line; a primary coil wound around the outer circumferential surface of the bobbin; and a secondary coil wound around the wound primary coil, a wound outer surface of the secondary coil having a shape parallel to the axial line.

Abstract: A reactor is equipped with a coil having unit coils. First spacers are disposed in at least one of spaces between the unit coils and in a space between one of the unit coils and a supporting frame. Second spacers are disposed between the first spacers. The supporting frames, the first spacers, and the second spacers are traversed by bolts and are fixed to the bolts. A space is defined between the bolt and a wall surface of a through hole formed in the first spacer and traversed by the bolt. A spacing distance between adjacent first spacers in the central axis direction of the coil is greater than a central-axis-direction thickness of the unit coil located between the adjacent first spacers, the central-axis-direction thickness of the unit coil being of when the coil is not energized.

Abstract: In one aspect, an electric coil structure is disclosed. The electric coil structure includes a magnetic core and a substrate. The substrate comprises a conductive material that is embedded in an insulating material. The substrate has a first portion and a second portion and the first portion of the substrate is wrapped around the core. The substrate can have a first portion having a plurality of contacts and a second portion having a corresponding plurality of edge contacts. The coil structure includes an alignment structure. The alignment structure can facilitate attachment of the first portion to the second portion to define a coil about the magnetic core. The alignment structure can comprise a redistribution substrate. The redistribution substrate can be disposed between the first portion and the second portion with the conductive material of the first portion electrically connected to the conductive material of the second portion through the redistribution substrate to define at least one winding.

Abstract: A coil device with a cooling structure includes: a coil unit that has a core structure having one or more leg parts and one or more coils wound around the one or more leg parts; and a flow-rectifying member having a flat plate portion covering a face of the one or more coils and flow-rectifying ribs inwardly protruding from an inner surface of the flat plate portion, the flow-rectifying ribs extending in a direction parallel to center axes of the one or more coils and being positioned to face side boundaries of the face of the one or more coils. The flat plate portion and the flow-rectifying ribs form a first air cooling channel at a substantially uniform gap outside of the one or more coils along the direction parallel to the center axes thereof, the first air cooling channel passing cooling air to air-cool the one or more coils.

Abstract: One object is to provide a new improvement for increasing an effective magnetic permeability of a coil component. A coil component according to one embodiment of the present invention includes a drum core having a first flange, a second flange, and a winding core coupling said first flange to said second flange, a winding wire wound on the winding core, and an exterior portion provided around the winding core so as to cover at least part of the winding wire. Said exterior portion has an easy magnetization direction oriented parallel to an axis of the winding core.

Abstract: A transformer is disclosed. The transformer includes a first coil including a first stack of wire disks stacked in a first direction; an exterior barrier arranged to form a first air gap between outer sides of the wire disks of the first stack of wire disks and the exterior barrier; an interior barrier arranged to form a second air gap between inner sides of the wire disks of the first stack of wire disks and the interior barrier; a wind generator arranged to generate an air flow in the first direction; a core in the form of a cylinder that is surrounded by the first coil; and an air guiding plate fixed to one of the exterior barrier and the interior barrier, to guide the air flow in a second direction along first stack gaps between the wire disks of the first stack of wire disks. The transformer effectively improves the heat dissipation of the coil and thus allows a smaller transformer in size.

Abstract: The application relates to a galvanic separating apparatus, including a printed circuit board, the printed circuit board including a first soldering pad, a second soldering pad and a recess, whereby the pads are arranged on a lower side of the printed circuit board thereby defining a clearance and/or creepage distance between the pads, and the recess is arranged between the pads, a primary insulated winding layer connected to the first soldering pad and a second insulated winding layer connected to the second soldering part, whereby the winding layers are arranged on an upper side of the printed circuit board, and an insulating layer, whereby the insulating layer extends from the upper side through the recess and protrudes on the lower side beyond the printed circuit board thereby increasing the clearance and/or creepage distance.

Abstract: A coil component includes an edgewise coil and a bobbin around which the edgewise coil is wound. The bobbin includes a tubular bobbin body, and plural position-limiting protruding portions arranged in plural portions on the outer peripheral surface of the bobbin body and limit the position of each winding portion of the edgewise coil in the axial direction of the bobbin body. The plural position-limiting protruding portions include first and second position-limiting protruding portions, which are disposed at different positions in the axial direction of the bobbin body. The edgewise coil includes a first winding portion that is in pressure contact with the first position-limiting protruding portion toward the second position-limiting protruding portion, and a second winding portion that is in pressure contact with the second position-limiting protruding portion toward the first position-limiting protruding portion.

Abstract: An electronic component including a body portion and an electrode disposed on the body portion is provided. The electrode includes a first metal layer, a second metal layer, and a third metal layer. The first metal layer contains silver (Ag) as a main component and includes first dispersion portions containing glass as a main component and second dispersion portions containing nickel as a main component. The second metal layer is disposed on the first metal layer and contains nickel (Ni) as a main component. The third metal layer is disposed on the second metal layer and contains tin (Sn) as a main component. An area of the first dispersion portions is larger than an area of the second dispersion portions in a sectional view of the electrode.

Abstract: The present disclosure provides a switching power supply, an EMI filter, a common mode inductor and a wrapping method for the common mode inductor. The common mode inductor includes a first coil winding and a second coil winding. The wrapping method for a common mode inductor includes steps of: disposing two isolation blocking sheets at different positions of a magnetic core; wrapping the first coil winding around the magnetic core, wherein the first coil winding is divided into two wrapping areas by one of the isolation blocking sheets; wrapping the second coil winding around the magnetic core, wherein the second coil winding is divided into two wrapping areas by the other one of the isolation blocking sheets, wherein the first coil winding and the second coil winding are symmetrically wrapped.

Abstract: An electronic component has a shaft, a flange formed at an end of the shaft and constituting a core together with the shaft, a coiled conductor wound around the shaft, and an electrode terminal formed on the flange and connected electrically to an end of the conductor; wherein the shaft and flange are made of metal magnetic grains containing Fe which are bonded to each other by bonding of oxide film formed on each metal magnetic grain, and the shaft is more densely filled with the metal magnetic material than is the flange. The electronic component can achieve size reduction and frequency increase by improving the magnetic permeability while also improving the plating property for the terminal electrode.

Abstract: A low-cost and high-precision current sensing device and methods for use and manufacturing. In one embodiment, the current sensing apparatus comprises a Rogowski-type coil which is manufactured in segments so as to facilitate the manufacturing process. In an exemplary embodiment, the current sensing apparatus segments comprise a number of bobbin elements that are wound and subsequently formed into complex geometric shapes such as torus-like shapes. In an alternative embodiment, bonded windings are utilized which allow the segments to be formed without a bobbin or former. In yet another alternative embodiment, the aforementioned current sensing devices are stacked in groups of two or more. Methods of manufacturing and using the aforementioned current sensing apparatus are also disclosed.

Abstract: A magnetic assembly includes a bobbin with two end flanges. A passageway extends longitudinally between the end flanges. An inner core extends through, and is centered in, the passageway. The inner core has first and second end surfaces, each surface proximate to one of the end flanges. A rectangular outer core is positioned around the bobbin with inner surfaces of the outer core close to the outer surfaces of the end flanges of the bobbin. A respective gap is formed between each end of the inner core and the adjacent inner surface of the outer core. The passageway includes crushable ribs that secure the inner core within the passageway. The outer surfaces of the end flanges include crushable ribs that secure the core with respect to the bobbin. The passageway and inner core may have an oval-shaped profile. The passageway and inner core may have a circular profile.

Abstract: A transformer including first coil unit and second unit, wherein one or more coils are wound on the bobbin of insulating material in at least one of the first coil unit and the second unit, and wherein the bobbin is formed with at least one partitioning flange for partitioning a coil winding surface of the bobbin into two winding surfaces along the longitudinal direction of the bobbin, is disclosed.

Abstract: Air core reactor includes a coil connected between first and second terminals. The coil is made of a succession of bundles of conductor (B1, B2, B3, . . . , BN) connected in series along an axis between the first terminal and the second terminal. Each bundle is made of one wire wound around the axis to form a multi-layer winding having a cross-section of N winding layers in a direction perpendicular to the axis, from a winding layer of rank 1 which is the closest to the axis to a winding layer of rank N which is the furthest from the axis. Each perpendicular winding layer includes several winding layers in the direction of the axis. The number of axial winding of the perpendicular winding layer of rank j (j=2, . . . , N) is equal or less than the number of axial winding layers of the perpendicular winding layer of rank j?1.

Abstract: Provided is an electronic component having a core that can achieve size reduction and frequency increase by improving the magnetic permeability further while also improving the plating property for the terminal electrode. An electronic component has a shaft, a flange formed at an end of the shaft and constituting a core together with the shaft, a coiled conductor wound around the shaft, and an electrode terminal formed on the flange and connected electrically to an end of the conductor; wherein the shaft and flange are made of a metal magnetic material, and the shaft is more densely filled with the metal magnetic material than is the flange.

Abstract: A coil for a transformer includes first and second coil segments with each coil segment being defined by successive layers of wound conductor sheeting. The coil segments are electrically connected together and are adjacent, defining a space there-between. A plurality of cooling duct pairs are disposed between certain of the layers in each of the first and second coil segments such that, for each cooling duct pair, an end of a cooling duct disposed in the first coil segment is adjacent to an end of a cooling duct disposed in the second coil segment, with the ends being disposed in the space. A connector connects the adjacent ends of each pair of cooling ducts.

Abstract: There is provided a coil component having a significantly reduced size and able to be easily manufactured, the coil component including a winding part formed as a groove having a ring shape; a plurality of coils inserted into and wound in the winding part; and a sealing part filling an internal space of the winding part having the coils wound therein and embedding the coils therein.

Abstract: An electrical system having an underlying structure resembling the double helix most commonly associated with DNA is used to produce useful electromagnetic fields for health applications and/or medical applications.

Abstract: A coil component comprises: a coil bobbin, which has a coil-winding section in an outer circumferential portion so that a coil is to be wound on the coil-winding section, and which has a through-hole in a central portion thereof; a first core and a second core, which have a plurality of magnetic legs respectively, wherein a certain leg of the plurality of the magnetic legs of the first core and a certain leg of the plurality of the magnetic legs of the second core are inserted into the through-hole of the coil bobbin to face each other with a predetermined gap, and wherein facing surfaces of the certain legs of the magnetic legs are fixed by an adhesive; and a protective cover, which is positioned between the coil bobbin and the certain legs to suppress the adhesive from being attached to the coil bobbin.

Abstract: Disclosed herein are embodiments of devices for measuring electrical current and related systems and methods for forming and using such devices. According to certain embodiments, devices according to the present disclosure may comprise Rogowski coils. Also disclosed are systems and methods for forming a current measuring device using a bobbin that may allow for the use of a continuous length of wire for all windings associated with the current measuring device. Automated manufacturing techniques may be utilized to facilitate the manufacture of devices for measuring electrical current and/or may reduce the cost of such devices. Various embodiments disclosed herein include the use of a bobbin that may be selectively configured between a linear configuration and a closed configuration. One or more current sensors disclosed herein may be utilized in connection with a motor management relay or other type of intelligent electronic device.

Abstract: Air core reactor includes a coil connected between first and second terminals. The coil is made of a succession of bundles of conductor (B1, B2, B3, . . . , BN) connected in series along an axis between the first terminal and the second terminal. Each bundle is made of one wire wound around the axis to form a multi-layer winding having a cross-section of N winding layers in a direction perpendicular to the axis, from a winding layer of rank 1 which is the closest to the axis to a winding layer of rank N which is the furthest from the axis. Each perpendicular winding layer includes several winding layers in the direction of the axis. The number of axial winding of the perpendicular winding layer of rank j (j=2, . . . , N) is equal or less than the number of axial winding layers of the perpendicular winding layer of rank j?1.

Abstract: There are provided a coil for cordless charging, which may be formed as a thin coil in spite of the presence of a plurality of coils included therein, and a cordless charging apparatus using the same. The cordless charging apparatus includes: a coil unit including coil substrates having a coil pattern and a connection substrate having one end interposed between the coil substrates and electrically connected to the coil pattern and the other end electrically connected to the outside; and a case accommodating the coil unit therein.

Abstract: Disclosed herein is a common mode filter having a signal compensating function, including: a magnetic substance substrate included as a base of the common mode filter; a first conductor coil portion that is formed on a surface of the magnetic substance substrate and is included to remove common mode noise generated in a circuit; and a second conductor coil portion that is electrically connected to the first conductor coil portion to be formed on an upper portion of the first conductor coil portion, and is included to compensate for a signal reduction portion of the circuit due to removal of noise by using the first conductor coil portion.

Abstract: An electromagnetic interference (EMI) filter assembly includes an EMI core having a center opening. The EMI core is configured to prevent interference between busbars of an uninterruptible power supply. The EMI core surrounds members of the busbars. At least one bracket is disposed though the center opening and configured to hold the EMI core to the busbars. The at least one bracket includes flanges. The flanges include slots in which the EMI core is held. Spacers are disposed between the busbars. Fasteners connect the at least one bracket, the spacers, and the busbars to each other.

Abstract: An electrical system having an underlying structure resembling the double helix most commonly associated with DNA is used to produce useful electromagnetic fields for health applications and/or medical applications.

Abstract: Provided is an MCP including a plurality chips stacked therein. Each of the chips includes a plurality of inductor pads configured to transmit power or signals, and at both sides of a reference inductor pad, a first and a second inductor pads are formed to generate magnetic fluxes in different directions from each other.

Abstract: It is described a single-phase or three-phase distribution electric transformer, of solid insulation, for use in aerial installation, in poles, in platforms or pedestals, or installation in underground distribution network for operation in air environment, semi-submerged or submerged. Such transformer comprises at least one high voltage winding (3) and at least one low voltage winding (2) concentrically assembled around a core column (1.2,1.3), the low voltage and high voltage windings (2,3) being electrically isolated from a solid material, a core window (20) being defined as a space between two core columns (1.2,1.3), the transformer comprising at least one electrical insulation sheet (4) assembled on at least a core window (20) of said transformer, the assembly of the electrical insulation sheet (4) being defined in the longitudinal direction (300) of the transformer. Such sheet (4) avoids the formation of spiral around the core by immersion water or conductive dust.

Abstract: A plurality of magnetic extraction bumps are incorporated into a cyclotron that further includes (a) a pair of magnetic coils encircling a central axis and positioned on opposite sides of a median acceleration plane and (b) a magnetic yoke encircling the central axis and including a return yoke that crosses the median acceleration plane and a first and second pole on opposite sides of the median acceleration plane. The magnetic extraction bumps extend in series radially from the central axis on opposite sides of the median acceleration plane and can be used to extract an orbiting accelerated ion from the cyclotron.

Abstract: A multi-layer, multi-turn structure for an inductor having a plurality of conductor layers separated by layers of insulator is described. The inductor further comprises a connector electrically connected between the conductor layers. The structure of the inductor may comprise a cavity therewithin. The structure of the inductor constructed such that electrical resistance is reduced therewithin, thus increasing the efficiency of the inductor. The inductor is particularly useful at operating within the radio frequency range and greater.

Abstract: A transformer without coil racks includes a winding set, multiple conductive plates and an insulation mounting sheet. The winding set includes a coil portion and a magnetic core set running through the coil portion. The magnetic core set includes at least one inner magnetic core portion and at least two outer magnetic core portions that are spaced from each other by a gap. Each conductive plate includes a connecting section and two extended arms connected to two ends of the connecting section and running through the gap. The insulation mounting sheet includes multiple retaining slots corresponding to the gap to allow the extended arms to pass through and multiple retaining portions each being formed between two neighboring retaining slots to prevent the extended arms from contacting each other. The conductive plates run through the retaining slots and are confined by the retaining portions from moving.

Abstract: Disclosed herein is a coil bobbin for a superconducting magnetic energy storage. The coil bobbin includes coil bobbin frames, superconducting coils, first support plates, second support plates and a center frame. The coil bobbin frames are provided in such a way as to face each other. The superconducting coils are wound around the respective coil bobbin frames. The first support plates are provided on surfaces of the respective coil bobbin frames that are on faces that are opposite to the surfaces between the coil bobbin frames that face each other. The second support plates are provided on the respective facing surfaces of the coil bobbin frames. The center frame is disposed between the second support plates and has an annular plate shape having a thickness that is gradually reduced towards a center of the toroidal arrangement.

Abstract: A vacuum cast or “solid” transformer coil assembly and a method of manufacturing thereof are provided. A solid transformer coil assembly, according to an embodiment of the invention, includes a dielectric substrate, the coil windings provided around the substrate, and an epoxy compound encapsulating the substrate and the coil windings. The substrate is provided with raised “buttons” comprising the same epoxy material as the epoxy compound used for encapsulation. The buttons maintain a specific distance between the coil and the dielectric substrate. The buttons are arranged such that they support the windings and allow the encapsulating epoxy to flow around them flooding the entire mold without entrapping air or creating voids.

Abstract: There is provided a transformer having a minimized leakage inductance. The transformer includes: a bobbin including a plurality of partitioned spaces; and a plurality of coils wound and stacked in the plurality of partitioned spaces, wherein the respective coils are wound so as to be disposed in the plurality of partitioned spaces, and at least one of the coils is a multi-insulated coil.

Abstract: A dry-type transformer includes at least one high-voltage winding and one low-voltage winding. The windings are operatively connected to one another by an electromagnetic field, and each winding is constructed from winding conductors, wherein the high-voltage winding and the low-voltage winding have a defined distance from one another, and spacers are arranged between the windings and maintain the defined distance.

Abstract: An electromagnetic coupling device includes a field core, a surge voltage absorbing member, and a storage member. The field core is provided inside an exciting coil. The surge voltage absorbing member is connected to the exciting coil. The storage member is made of an insulating material and includes a recess portion to store the surge voltage absorbing member. A through hole is formed in an outer wall of the field core. The storage member is inserted into the through hole with an opening of the recess portion facing the exciting coil. The surge voltage absorbing member is inserted in the recess portion so as to be positioned outside the field core by the exciting coil.

Abstract: The disclosure relates to a transformer having a yoke which has a crosspiece and at least two limbs, over which limbs a coil is placed in each case, and having at least one carrier on which the crosspiece is fixed and which has bearing faces for the coils. At least two supporting blocks for each coil are mounted on each bearing surface. The supporting blocks are fitted with elastic compensation elements on the coil-side carrying face and have, on their longitudinal side faces, which run perpendicular to a carrying surface, at least one strip which extends the creepage path and runs in the longitudinal direction and parallel to the carrying surface of the supporting block.

Abstract: An improved choke assembly for a power electronics device is provided. More specifically, a choke assembly with improved protection from environmental conditions such as dirt and water is provided. An improved choke assembly may include an insulative housing for an inductor coil that seals the inductor coil from the environment.

Abstract: A Nb3Sn superconducting coil can be formed from a wire including multiple unreacted strands comprising tin in contact with niobium. The strands are wound into a cable, which is then heated to react the tin and niobium to form a cable comprising reacted Nb3Sn strands. The cable comprising the reacted Nb3Sn strands are then mounted in and soldered into an electrically conductive channel to form a reacted cable-in-channel of Nb3Sn strands. The cable-in-channel of reacted Nb3Sn strands are then wound to fabricate a superconducting coil. The Nb3Sn superconducting coil can be used, for example, in a magnet structure for particle acceleration. In one example, the superconducting coil is used in a high-field superconducting synchrocyclotron.

Abstract: A low profile coil-wound bobbin is disclosed. A low profile coil-wound bobbin includes a spool and a terminal. The spool is configured to have a coil-wire arrangement wound around the spool. The terminals are to be coupled to the coil-wire arrangement and a first side of a circuit board. The terminal is configured to mechanically and/or electrically couple the low profile coil-wound bobbin to the first side of the circuit board such that the low profile bobbin extends through the circuit board to another side of the circuit board.

Abstract: The present invention provides a power transmission transformer of which workability in implementing and reliability of connection are considered in a noncontact power transfer device using individual self-oscillation circuits. The power transmission transformer for a noncontact power transfer device including a transmitting coil L1 and a drive coil L2 for self-oscillation on a power transmission device side includes a bobbin in which the transmitting coil and the drive coil L2 are disposed, in which the transmitting coil and the drive coil L2 are configured by an air-core coil using self-bonding wire, and the bobbin 1 includes a winder spindle 1a, 1b on both surfaces opposed to each other across a collar 2 formed of a flat plate, and a mating portion 3 for mating with an external portion in an end portion of the winder spindle 1b, and the drive coil L2 is mounted on the winder spindle 1b and the transmitting coil L1 is mounted on the other, opposed winder spindle 1a across the collar.