Abstract: A coil includes a plurality of coil conductor pieces, first and second cores and a case. The plurality of coil conductor pieces is made of a high magnetic permeability material. The first and second cores include through-holes in parallel. The through-holes allow penetration of the coil conductor pieces. The first core and the second core are stored in the case. At least one end part of one of the coil conductor pieces penetrating through the through-holes of the first core and the second core is coupled to an end part of the other coil conductor piece on the outside of the case. A coil conductor circling between the first and second cores is made up of the plurality of coil conductor pieces.

Abstract: Disclosed is an electrolytic capacitor comprising a capacitor element formed by winding an anode foil having pits with a diameter of not less than 0.1 .mu.m formed on the surface thereof and a cathode foil with a separator provided interposed therebetween, the separator having been coated with PVA which is then dried, the capacitor element being in contact with an electrolytic solution for electrolytic capacitor containing ethylene glycol, whereby the electrolytic solution is gelled. An electrolytic capacitor which comprises a capacitor element formed by winding an anode foil and a cathode foil with a separator provided interposed therebetween, the separator having been prepared by mixing filament fibers formed by extruding PVA solution into a gas, the capacitor element being impregnated with an electrolytic solution, is also disclosed.