Abstract: A multiple twisted conductor, which comprises at least two individual twisted conductors (1, 2) comprising individual enamel insulated partial conductors (3), and a common sheath (5) enclosing the individual twisted conductors (1, 2). The individual twisted conductors (1, 2) are arranged inside the common sheath (5) without any insulating layer of their own.

Abstract: The invention relates to a varnish for winding wires, the varnish comprising a copolymer obtained from a thermoplastic or thermosetting resin and containing units derived from silane, and a mineral filler selected from compounds of B, Al, Ti, Zn, Zr, Cr, Fe, silicates, and mixtures thereof. The resin is selected from polyamide imide (PAI), polyester imide (PEI), polyimide (PI), polyester (PE), polyurethane (PU), and polyvinylacetal (PVA). The varnish makes it possible to obtain winding wires of lifetime that is increased by having improved ability to withstand partial discharges and voltage peaks, even at high temperatures. The invention is applicable to manufacturing coils, in particular for variable frequency controllers and converters.

Abstract: An enameled wire having high resistance to partial discharges includes an electrical conductor and at least two layers of enamel on the conductor. At least one of these layers is made from resin charged with weakly conductive particles. The outermost layer constitutes an overcoat and is made from thermo-adherent resin. At least the layer directly underlying the overcoat is made from the resin charged with the particles.