Abstract: Improvement for power supplies include a protection circuit having a first L-C filter network, a second L-C filter network and a voltage clamping device such as a zener diode which is disposed between the two L-C filter networks. The protection circuit reduces the magnitude of overvoltage input transients which might otherwise damage the internal components of the inverter. For generating very high output votlages, the power supply includes a high voltage transformer and a Crockoft-Walton voltage multiplier coupled thereto. The high voltage transformer is coupled to an inverter through a coupling circuit which includes a capacitor in one leg of the primary winding and a parallel connected resistor/inductor in the other leg of the primary winding of the high voltage transformer. The high voltage transformer is formed of a multi-sectioned bobbin which is defined around an axially extending core.

Abstract: An improved coil end face insulator and the application technique therefor serve to accurately and cost-effectively insulate the end windings of an electrical coil from the transverse arm of a ferromagnetic core spaced closely thereto. The insulator is of annular, one-piece construction, and comprises adhesively-backed tape. The insulators are dispensed in a convenient manner for rapid and accurate application to the respective end faces of coils respectively positioned on a mandrel or fixture.

Abstract: Disclosed is a water-cooled winding for an electromagnetic stirrer, which comprises a coil including a plurality of wound flat type wires having a wire-insulating turn insulation, and a porous polyamide fiber having an air permeation rate not higher than 25 seconds/100 cm.sup.3 of air covering the periphery of the coil, which is impregnated with an epoxy resin composition. In this water-cooled winding, the polyamide fiber is sufficiently impregnated with the epoxy resin composition and this epoxy resin composition is cured stably and assuredly. Accordingly, the mechanical rigidity of the winding is sufficiently high, and the water resistance of the winding is highly improved and is maintained for a long time, with the result that the life of the winding is greatly prolonged.

Abstract: A process for producing a flat coil of high reliability and free from the problem of short-circuiting, and capable of high productivity. The process includes steps of forming an insulator layer on a metal foil ribbon, winding the metal foil around a center shaft or mandrel while pressing the insulator layer toward the center shaft to form a rolled up metal foil body. A strip electrode of conductive metal may be integrally attached to the inner or outer periphery of the coil or both to provide electrical connection to the turns. An insulating resin layer may be formed at an outer end of the metal foil, and a metal reinforcing layer can be formed on the outer periphery of the rolled up body other than at the insulating resin layer by electroplating to form a coil block. The rolled up body or coil block is then cut by electric discharge machining in a direction transverse to the center shaft to form flat coils at a predetermined thickness.

Abstract: An insulated coil assembly for use in electrical apparatus includes a coil of conductive wire formed in a predetermined configuration around selected portions of which is disposed an insulating layer comprised of a cured resin impregnated, close woven, heat-cleaned glass fiber tape.

Abstract: In a high-voltage transformer of particularly small size comprising a magnetic circuit and a coil shell on which is wound a secondary winding consisting of one or a number of separate secondary coils, each secondary coil is contained within a channel closed by an insulating ring made up of two segments. The two ring segments are assembled around the channel in a movement performed in the same plane as that of the channel.

Abstract: Secondary winding configurations and methods particularly applicable for toroid transformers are described for winding secondary windings over the indexed primary winding and toroidal core. The secondary winding is formed in the configuration of a multifilar winding of a plurality of coplanar parallel filaments with a first elongate strip of electrically insulating material bonded to the filaments on one side and a second elongate strip of electrically insulating material bonded to the filaments on the other side and to the first elongate strip. The resulting electrically insulated multifilar strap winding contains the filaments in substantially parallel coplanar relationship. The multifilar strap winding is wound around the toroidal core in substantially equally spaced turns. The strap winding maintains the filaments substantially in equally spaced relationship relative to each other over irregular surfaces and compound curvature of the toroidal core without crossover.

Abstract: Optical-waveguide coils are used in rotation rate measuring instruments. To protect the optical-waveguide coil (1) from external influences, such as sound waves, pressure, and temperature changes, which may result in measurement errors, it is wound on a coil form (2) of soft elastomer under low tension. The coil unit so formed (1/2) is then placed in the annular groove (4) of a housing (3/5). Spacers at the coil form (2) position the coil unit (1/2) in the annular groove in such a way that the coil (1) is exactly in the middle of the annular groove (4). The remaining free space of the annular groove (4) is then filled with a sealing compound (6) in a vacuum. The sealing compound also spreads between the windings of the coil (1). It is preferably the same material as that from which the coil form (2) is made.

Abstract: A layer winding for transformers, measuring transformers, choke coils or the like is to be so improved that the insulation of such a layer winding exhibits practically no free spaces in the insulating tape edge areas. This is assured by the method of manufacture in that when reaching the outer end face (12) of a layer winding edge (4), the insulating tape (2) is continued to be wound and the band portion (13) of the insulating tape (2) which projects beyond the edge face (12) is continuously cut off. The remaining residual portion of the insulating tape (15) is then continued to be wound with zero pitch for such length of time until the free spaces which otherwise occur at the layer winding edge (4') are filled out.

Abstract: An eddy current probe, excitable at frequencies equal to or greater 7 mhz., includes a substantially planar, spiral-like, unilaminar coil mounted on an insulative substrate. A protective layer covers the coil and is adopted to present only a minimal mechanical barrier between the coil and a region of material under test. The coil is a continuous run of copper having an effective diameter no greater than 2 mils. The coil, substrate and protective layer are a printed circuit board. A method of detecting flaws is also disclosed.

Abstract: A method for the manufacture of a layer winding for transformers, measuring transformers, choke coils or the like is to be so improved that the insulation of such a layer winding exhibits practically no free spaces in the insulating tape edge areas. This is assured in that when reaching the outer end face (12) of a layer winding edge (4), the insulating tape (2) is continued to be wound and the band portion (13) of the insulating tape (2) which projects beyond the edge face (12) is continuously cut off. The remaining residual portion of the insulating tape (15) is then continued to be wound with zero pitch for such length of time until the free spaces which otherwise occur at the layer winding edge (4') are filled out.

Abstract: Secondary winding configurations and methods particularly applicable for toroid transformers are described for winding secondary windings over the indexed primary winding and toroidal core. The secondary winding is formed in the configuration of a multifilar winding of a plurality of coplanar parallel filaments with a first elongate strip of electrically insulating material bonded to the filaments on one side and a second elongate strip of electrically insulating material bonded to the filaments on the other side and to the first elongate strip. The resulting electrically insulated multifilar strap winding contains the filaments in substantially parallel coplanar relationship. The multifilar strap winding is wound around the toroidal core in substantially equally spaced turns. The strap winding maintains the filaments substantially in equally spaced relationship relative to each other over irregular surfaces and compound curvature of the toroidal core without crossover.

Abstract: Transformer coils (19) are provided on a tubular section (5) of a coil former (3) at least one of the coils is separated from the next coil by mounting the second of said coils on an electrically insulating foil (41) wound around the first coil. Each of the two coils (19) is located in a winding space (27) which extends from the center of the tubular section (5) to both sides in the axial direction to boundaries (37) located at a predetermined distance from the ends thereof, whereas the foil (41) extends in the axial direction beyond those boundaries.

Abstract: An induction heating coil having fluoroplastic coated polyimide tape wrapped windings for providing a bonded, solid monolithic structure. The induction heating coil includes a cooling heatsink of predetermined size and shape fused in relationship to a plurality of consecutive turns of current-carrying coil windings. A plurality of fluoroplastic coated polyimide sheets are fused to the coil body between the coil body and a fluoroplastic face sheet forming the outer wear surface of the induction heater coil, thereby providing a non-stick surface for release of hot melt adhesives.

Abstract: A dry type, air cooled transformer having a mitered magnetic core and a compression bonded coil. The coil on each of the core legs is generally rectangular in shape and comprises a plurality of layers of wound conductor with the conductor layers in the end portions of the coil being spaced apart to form a plurality of air ducts for the passage of cooling air therethrough. The conductor layers in each of the side portions of the coil are compressed and then bonded together in their compressed state by means of a heat cured adhesive coated on opposite sides of the sheets of insulation between adjacent layers. This compression bonding of the coil sides squares up the inner and outer surfaces of the coil so as to improve the coil and core space factors thereby allowing a smaller core. Conversely, compression bonding allows higher output power ratings to be achieved by packing added conductor material through the same size core window.

Abstract: Several embodiments of coil assemblies suitable for a variety of uses are disclosed herein all of which employ spiral windings which minimizes coil layer-to-layer voltage gradients to levels which conventional enamel wire insulation is able to withstand. In one embodiment a spiral winding is fabricated in strip form using a continuous strand of wire secured to a continuous ribbon-like substrate by an adhesive composition which may be provided on the wire so as to form a plurality of spiral windings on segments or portions of the substrate, each winding having one turn in each radial layer. The substrate will include other segments located between each winding portion to provide insulating means for the spiral windings and for the transition of the wire as it passes to the next successive winding containing segment.

Abstract: An induction heating coil having fluoroplastic coated polyimide tape wrapped windings for providing a bonded, solid monolithic structure. The induction heating coil includes a cooling fin of predetermined length extending in interleaved relationship between a plurality of consecutive turns of current-carrying coil windings. A plurality of fluoroplastic coated polyimide sheets are fused to the coil body between the coil body and a fluoroplastic face sheet forming the outer wear surface of the induction heater coil, thereby providing a non-stick surface for release of hot melt adhesives.

Abstract: Disk coil winding formed of interwound single or double coils wherein insulation of outer turns opposite inner and outer generated surfaces, respectively, of the winding is reinforced in comparison with normal insulation of conductors of the winding including auxiliary insulations angularly surrounding at least one edge of at least two turns, respectively, in at least the coils disposed at an input of the winding, starting from the inner and the outer generated surface, turn capacitance between turns free of auxiliary insulation being increased with respect to turn capacitance at turns provided with the auxiliary insulations.

Abstract: A method of making a cellulose-free electrical winding having a tubular configuration in which layers of insulating resin and conductors are alternately disposed in a concentric pattern, with opposite edges of the conductor turn layers being coated with overlapping layers of resin. The resin is applied as a liquid in thin layers as the winding is being formed, and the liquid resin is instantly gelled to provide mechanical support for the next winding layer.

Abstract: An electric roller-type capacitor formed with a capacitor winding built into a housing and having end-face contact layers, includes a wrapping consolidating the capacitor winding, the wrapper being formed of a fiberglass-reinforced synthetic resin composite, and method and device for producing the capacitor.

Abstract: An improved magnetic core for an electrical transformer, and a method and apparatus for forming the core, are disclosed wherein the corners of core windows are configured to decrease the magnetic path length, thereby reducing the core losses and the amount of material necessary to construct the core. One exemplary embodiment includes a core window opening having an outer corner radii that are larger than the inner corner radii. Alternatively, the core window may have corners of a non-constant radii, with the outer corners having a more gradual or gentle curvature. These and other disclosed embodiments also enhance the ease of assembly of the transformer core and thus decrease or eliminate damage to the magnetic material during assembly.

Abstract: A transformer winding characterized by a plurality of electrically connected disc or pancake coils disposed around a core leg in which the inner and outer edges of adjacent coil pairs are radially offset, enabling the insulative members which surround the edges of each such coil pair to be curved and thus more closely conform to the equipotential planes of the dielectric field.

Abstract: Electrical inductive apparatus characterized by pancake coils comprised of an outer layer and a plurality of inner layers formed by spirally winding an elongated conductor which conductor has a plurality of strands formed in a row of strands in each layer including an end strand at each end of the row, the end strand being enclosed in dielectric covers with each layer being encased in a dielectric casing, whereby the end strands of adjacent layers are sufficiently insulated to prevent electrical breakdown therebetween.

Abstract: A conductor of a rectangular cross-section is overlapped with an insulator having a greater width than the width of the conductor and wound to form a coil assembly. The oversized portions of the insulator are folded and cemented together. The coil assembly is mounted on a stator pole core so that the folded insulator portions are respectively adjacent to the pole piece of the core and to the inner wall of a cylindrical yoke when the pole core is secured to the yoke. The folded portions of the insulator are depressed by an amount sufficient to allow the coil assembly to be firmly clamped in position.

Abstract: A field coil insulation shield for a motor or generator is made of a single sheet of insulating material, and defines portions which substitute for the paper insulator conventionally disposed around a field pole and between a field coil and a motor frame, and portions which substitute for individual wrappings with tape to form the field coil and to protect it from the structure of the field pole which holds it in position. The portions which substitute for a wrapping of tape are provided with elongated projections which are latchingly received around the edge of a central aperture, through which the field pole passes.

Abstract: To reduce the ohmic losses in a sheet-wound transformer or reactor winding, edge regions of at least some of the turns of the conductor sheet forming the winding are located at a different distance from the geometric axis of the winding compared with the distance from said axis of a central conductor portion in a respective one of said turns. Preferably the conductor sheet in each turn substantially follows the flux lines for the resultant magnetic leakage flux which corresponds to a constant current density in the sheet. For example, the winding may be wound from a metallic foil whose edge regions are folded back on themselves, or end regions of the winding may be provided with inter-turn packings (e.g. of tape) to achieve the desired flared shape of the turns at the ends of the winding.

Abstract: A sheet winding (7) in a transformer is made with double-curved conductor sheets. Some of the winding turns are mutually different as regards the curvature visible in an axial section. This has been achieved by arranging a number of filling members at each one of the end surfaces of the winding. Each filling member contains several turns of a filling tape (14), which are evenly distributed in a group of mutually adjacently positioned winding turns wound from a conductor sheet (9). Because the filling tape has different degrees of overlap in the different turns of the conductor sheet (9), the filling member will have approximately the same effect as a filling body which, in axial section, exhibits a wedge-shaped cross-section area.

Abstract: An insulating system is described that incorporates a cellulosic material which is impregnated with a nitrogen content no less than 0.2% by weight and a overall density not greater than 0.9 gm/cm.sup.3. This cellulosic material when impregnated by a dielectric liquid such as transformer oil, exhibits a more uniform electrical stress distribution than papers having a density greater than 0.9 gm/cm.sup.3. The insulating system thereformed is particularly useful for application in low stress areas such as the layer insulation in a distribution class transformer.

Abstract: A transformer has an insulator interposed between respective primary and secondary coils wound on a coil bobbin which has an axial winding part and opposing radially extending flanges. The insulator is made from a continuous sheet of material which is corrugated to provide an insulating base having a width larger than the width of the winding part of the coil bobbin and from a continuous, plastic insulating sheet member having substantially the same width as the winding part. The corrugated insulated base material and insulating sheet member are wound between the primary coil and the secondary coil and the corrugated insulating base is bent at both side edges to be L-shaped to intimately fit to the inner surface of the flanges of the coil bobbin so as to provide an insulator which positively prevents coil wire at each end portion of the coil from dropping out of alignment with respective coil turns.

Abstract: A coil structure for cellulose-free transformer coils characterized by at least three helically wound layers disposed in a reversal pattern with wedge-shaped resinous insulators between each layer.

Abstract: A coil structure for cellulose-free transformer coils characterized by a plurality of helically wound layers disposed in a zig-zag pattern with wedge-shaped resinous insulators between each layer.

Abstract: Two different stator windings of an electric motor are separated by insulating elements of die-cut sheet material. Each of these elements comprises a pair of end panels which separate the windings at the two ends of the stator, and a series of parallel strips which interconnect the end panels and each of which extends within one of the stator slots. One of the end panels has, extending from its edge opposite that from which the strips extend, at least two consecutive flaps folded one over the other in the manner of a sleeve. The sleeves of the insulating elements receive the joins between the wires of the windings and the associated supply leads.

Abstract: An electrically insulated coil comprising a coil; and a mica tape wound around said coil and containing a resin composition; said resin composition including an epoxy resin, a curing catalyst consisting of an aluminum compound, and a curing accelerator selected from the group consisting of a silane compound having a hydroxyl group and a polysiloxane compound having a hydroxyl group, said curing catalyst being added in an amount of 0.1 to 5% by weight based on said epoxy resin, said curing accelerator being added in an amount of 0.1 to 10% by weight based on said epoxy resin, and said resin composition being cured by heating after said mica tape is wound around said coil.

Abstract: An electrically insulated coil is composed of a coil and a mica tape containing a first resinous composition, wound upon the coil; the resinous composition containing a maleimide compound, an epoxy resin, a curing catalyst consisting of an aluminum compound, and a curing accelerator selected from the group consisting of a silane compound having a hydroxyl group and a polysiloxane compound having a hydroxyl group; the curing catalyst and the curing accelerator each being in an amount of about 0.0001 to 5% by weight based on the total amount of the maleimide compound and the epoxy resin; and the resinous composition being cured by heating after the mica tape is wound around the coil.The electrically insulated coil may further contain a second resinous composition comprising an epoxy resin and an acid anhydride, the second resinous composition impregnating the mica tape after the mica tape is wound around the coil, and being heat-cured together with the first resinous composition.

Abstract: A conductor bar for an electric machine is disclosed. At least one strip-like insert is provided on a surface of the conductor which forms an angle with an insulating sleeve enclosing the insert and conductor. Voids are produced at the edges of the insert which form impregnating canals for an impregnating medium to thereby improve the impregnability of the insulating sleeve.

Abstract: To reduce the ohmic losses in a sheet-wound transformer or reactor winding, edge regions of at least some of the turns of the conductor sheet forming the winding are located at a different distance from the geometric axis of the winding compared with the distance from said axis of a central conductor portion in a respective one of said turns. Preferably the conductor sheet in each turn substantially follows the flux lines for the resultant magnetic leakage flux which corresponds to a constant current density in the sheet. For example, the winding may be wound from a metallic foil whose edge regions are folded back on themselves, or end regions of the winding may be provided with inter-turn packings (e.g. of tape) to achieve the desired flared shape of the turns at the ends of the winding.

Abstract: A primary coil and N secondary coils of insulated electrically conductive wire are wound side-by-side about a ferrite core. Every T turns, the wire forming the secondary coils is wound over a separator strip forming an array of loops. A pair of spaced parallel conductors, for displacing the separator strip, are inserted in the array of loops and are soldered to the loops. The loop portion in the space between the conductors is removed. The assembly is covered with a layer of insulating material. The windings are repeated in a second or more layers over the first layer until the desired number of primary and secondary turns is formed.

Abstract: A transformer winding, made as a layered winding with striplike conductor insulated with at least one strip of insulation folded about the conductor, and a process for making the same, are disclosed. To make possible a fully automatic manufacture of the winding with sufficient mechanical strength and uniform impregnation, the insulation strip, in addition to insulation of the conductor, constitutes likewise the insulation of the layers. At the periphery of a winding layer there are punctate bonding places at predetermined distances only on the outside of the conductor insulation. The cross section of the layered winding may be essentially trapezoidal with the transition to the free outer end comprising one or more circular arcs with different radii.

Abstract: A flexible mica tape having a low gel time is prepared from a composition of an epoxy resin, an organotin salt, and catechol or pyrogallol. A mica sheet is immersed in the composition and the solvent is evaporated to form a tack-free A-staged resin. A conductor is wound with the tape and is impregnated with an impregnating resin using vacuum-pressure impregnation.

Abstract: This invention relates to electrical articles having an electrical coil such as high-tension transformers, ignition coils and the like which are excellent in withstand voltage and endurance; and to a method for manufacturing the same. These electrical articles have an electrical coil in which a sheet material such as paper, cloth or non-woven fabric comprising cellulose as major constituent is used as at least a part of interlayer insulator. Said sheet material is characterized by being impregnated with one or more pretreating resins selected from the group consisting of phenolic resins, s-triazine ring compound resins, and phenol-s-triazine ring compound co-condensation resins and further impregnated with a thermosetting resin composition containing an epoxy resin, unsaturated polyester resin, 1,2-polybutadiene resin or silicone resin, said resin being hardened.

Abstract: A primary coil and N secondary coils of insulated electrically conductive wire are wound side-by-side about a ferrite core. Every T turns, the wire forming the secondary coils is wound over a separator strip forming an array of loops. A pair of spaced parallel conductors, for displacing the separator strip, are inserted in the array of loops and are soldered to the loops. The loop portion in the space between the conductors is removed. The assembly is covered with a layer of insulating material. The windings are repeated in a second or more layers over the first layer until the desired number of primary and secondary turns is formed.

Abstract: A method for producing electrically insulated apparatus, which may be used in windings for rotary electric machines, for example, an induction motor, synchronous machines, DC machines or stationary induction apparatus, for example, transformers, and the product produced thereby comprising an electric conductor and an insulating layer formed around the electric conductor, wherein said insulating layer contains a resin having excellent permeability for the gas generated in the layer, e.g., a silicone resin, and a resin having excellent adhesive force in an appropriate blending ratio in order to impart excellent thermal resistance to the electrically insulated apparatus.

Abstract: A power transformer having an operating temperature in excess of 200.degree. C. and including a casing or tank, an electrical core and coil assembly having an asbestos based barrier material and being supported in said casing, and a low cost saturated hydrocarbon insulating fluid substantially filling the casing and having a vapor pressure at 200.degree. C. less than 10 millimeters of mercury and a flash point in excess of 230.degree. C.

Abstract: High voltage solid dielectric insulation system transformers and inductors have been designed and produced by a process which results in a substantial improvement in the high voltage, size and weight characteristics of magnetic components prepared therefrom.

Abstract: Insulation structures for use in the insulation space and with the phase barrier insulation of an electrical inductive apparatus. The insulation structures include at least one layer of spaced, vertically-extending spacer members which is surrounded on both sides by layers of electrical insulating sheet material. The insulation structures are disposed in movable relation with the adjacent windings and phase barrier insulation, thereby allowing relative movement between the windings and the insulation structures during a short circuit.

Abstract: An EMR coil assembly having a split housing including a coil-retaining body member and ring member attached thereto, the EMR coil assembly including a coil having a plurality of polyimide face sheets disposed between a polyester face sheet forming the outer wear surface of the coil and a major surface of the coil.

Abstract: An electromagnetic dent remover including a dent removal head containing an electromagnetic work coil capable of creating a locally concentrated magnetic field when first energized by a slow rising current followed by a fast pulsing counter current is disclosed. The electromagnetic work coil comprises a cylinder formed of a spirally wound metal strip whose convolutions are electrically insulated from one another by coatings or layers of electrical insulation. In one form, slots and holes, located in the walls of the coil, control the electrical current density within the coil to thereby produce the desired locally concentrated magnetic field. In another form, the ends of the coils are machined such that at least one magnetic field concentration projection projects outwardly from one annular end of the coil. The other end of the coil is machined such that it is a mirror image of the projection end.

Abstract: The induction coil of this invention is wrapped on a non-metallic core with convolutions of the coil adjacent to one another. An adhesive tape is applied over the convolutions with a lapped seam of the tape and with the tape preferably extending beyond both ends of the coil in order to hold the convolutions of coil against moving with respect to one another while the coil is being transported from the winding step to the next operation in which a jacket is molded over the coil in a cavity of an injection molding machine.

Abstract: A porous, electrical insulating adhesive substrate is made by (A) electrostatically coating a flexible sheet material with heat reactive adhesive resin particles, having an average particle size of between about 1 micron to 2,000 microns, the adhesive particles are applied in a predetermined pattern on the sheet covering from about 10 percent to 90 percent of the sheet material area, the area between the resin pattern not being coated; and then (B) heating the patterned coated sheet material between about 65.degree. C to 250.degree. C, forming a discontinuous, 0.25 mil to 25 mil (0.006 mm to 0.

Abstract: A transformer having a forced air cooling system is disclosed. The transformer includes an insulating oil which is forcibly moved in the transformer and an insulating sheet which is partially covered with particles, fibers or other forms of an inorganic material for producing a static charge of opposite polarity to the charge produced by the base material of the insulating sheet caused by relative motion due to forced flow of the insulating oil.