Abstract: Electrical insulation which has good dielectric strength, good radiation resistance, and good thermal resistance at temperatures of up to 500.degree. C. and, preferably up to 1700.degree. C., includes a substrate which is flexible, has the form of a filament, sheet, wrapper, tape or sleeve, and consists essentially of inorganic materials selected from the group consisting of inorganic fibers and metals, metalloids, or alloys; and at least one layer of at least one oxide of an alkoxide-forming element provided on the substrate to impregnate and/or coat same. The insulation is prepared by a process including applying a solution containing an alkoxy gel polymer, optionally additionally containing at least one inorganic material in finely divided form, to the substrate to provide a treated substrate useful as a preform when allowed to set under ambient conditions.

Abstract: Disclosed is an apparatus for determining the eccentricity of insulation on an elongated conductor comprising two flat parallel opposing electrodes positionable on opposite sides of an insulated conductor in physical contact with the insulation of the conductor, means for moving one of the two electrodes relative to the other in a direction parallel to the electrodes, whereby the insulated conductor is rotated therebetween, electrical contact means for making electrical contact to the conductor, means for translating the electrical contact means at the same rate that the insulating conductor is translated between the two flat opposing electrodes, and electrical means for determining the ratio of the capacitance of each of the two electrodes to the conductor as the insulating conductor is rotated between the two electrodes.

Abstract: Disclosed is a method of determining the eccentricity of the insulation on a round wire without making electrical contact with the wire. The insulated wire is passed between two pairs of opposing electrodes, pair A-C and pair B-D, positioned at a known distance from the insulated wire and spaced apart azimuthally at a known angle. Known, out of phase, alternating voltages are applied to each pair of electrodes. Signals are generated from the four electrodes that are proportional to (1) v.sub.A -v.sub.B +v.sub.C -v.sub.D and (2) -v.sub.A -v.sub.B +v.sub.C +v.sub.D, where v.sub.A, v.sub.B, v.sub.C, and v.sub.D are the voltages on electrodes A, B, C, and D, respectively. From those signals the eccentricity of the insulation on the wire can be determined by ##EQU1## where .vertline.q.vertline. is the magnitude of ##EQU2## The direction of the eccentricity can be determined from the difference in phase between the two signals.

Abstract: A void-free prepreg is made by contacting a porous sheet material with a resin so that resin enters the sheet, providing a subatmospheric pressure on one side of the resin-containing sheet to draw resin through the sheet, and then B-staging the resin-containing sheet.

Abstract: A coil is made having a plurality of layers of adjacent metal conductor windings subject to voltage stress, where the windings have insulation therebetween containing a small number of minute disposed throughout its cross-section, where the voids are voids filled with SF.sub.6 gas to substitute for air or other gaseous materials in from about 60% to about 95% of the cross-sectional void volume in the insulation, thus incorporating an amount of SF.sub.6 gas in the cross-section of the insulation effective to substantially increase corona inception voltages.

Abstract: Methods of constructing a void-free, cellulose-free electrical winding insulated with a solid resinous insulation. The method includes forming a plurality of conductor turns on a substrate, with each conductor turn being immersed in liquid resinous insulation as it is formed, to provide a void-free intermediate structure. The void-free aspect of the intermediate structure is maintained up to and including the final step of the method by building solid insulation, thin layer upon thin layer, from the liquid resinous insulation, while the conductor turns are being formed, with the solid insulation, as it is formed, providing a solid substrate for the continued application of liquid resinous insulation and subsequent conductor turns of the winding.

Abstract: Disclosed is a conductor coated with a fused and cured powder applied insulating coating over which is a coating of an ultraviolet B-stageable, thermally C-stageable liquid resin. The coating is cured to the B-stage and strands of the conductor are placed side-by-side. The coating is then cured to the C-stage which fuses the strands of the conductor into a solid mass. The adhesive coated conductors may be used to form transformer coils, transposed cables, or other articles.

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: An imide containing polymeric coating is electrophoretically formed on wire from an emulsion. The emulsion contains a polymer, an organic aprotic solvent for the polymer, an amine, and a polar precipitant in which the polymer is insoluble. The wire is passed through a conductive tube immersed in the solvent while a D.C. current is applied between the tube and the wire. The polymer coating on the wire is then cured.

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: Wire is cleaned by passing it through an electrolytic cleaner then through an ultrasonic rinse. The electrolytic cleaner comprises a graphite tube through which the wire passes, an alkaline aqueous solution between the wire and the graphite tube, and an electric current, at least half D.C., between the wire and the graphite tube.

Abstract: A build control is disclosed, for controlling the thickness of a coating on different sides of an elongated member such as a wire. The build control is a tube which is positioned around the wire as the wire passes through a fluidized powder. The end of the tube which is in the fluidized powder is notched so that the build of powder on each of the sides of the elongated member is more or less than would otherwise result.

Abstract: A build control is disclosed, for controlling the thickness of a coating on different sides of an elongated member such as a wire. The build control is a tube which is positioned around the wire as the wire passes through a fluidized powder. The end of the tube which is in the fluidized powder is notched so that the build of powder on each of the sides of the elongated member is more or less than would otherwise result.

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 patterned and then (B) heating the patterened 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.