To remarkably improve the homogeneity of the coating of an electric coil by making the coating contain at least one material having a polymeric matrix and nonlinear resistance and using a doped or undoped conductive polymer as the nonlinear-resistance material.
The wire used for forming an electrical coil is constituted of an unenamelled conductive core surrounded by a three-layer coating. The first layer 2 of the coating is composed of an insulating layer made of insulating varnish generally used for the insulation of conductors and the second layer 3 is composed of a material having nonlinear resistance. The outermost third layer 4 is formed similarly to the innermost layer 2 by using the insulating varnish generally used for the insulation of conductors. The nonlinear-resistance material is prepared by using a doped or undoped conductive polymer, particularly, a matrix containing 1-30 vol.%, preferably, 15-18 vol.% polyaniline. The nonlinear material, in addition, contains doped zinc oxide particles.
COTTEVIEILLE DENIS
RIEUX NADINE
FOULON NADINE
