Litz wire is a type of cable used in electronics to carry alternating current. The wire is designed to reduce the skin effect and proximity effect losses in conductors used at frequencies up to about 1 MHz. It consists of many thin wire strands, individually insulated and twisted / bunched, grouped or braided / woven together, as per the specific design and application. This often involves several levels (groups of twisted wires are twisted together etc.). This winding pattern equalizes the proportion of the overall length over which each strand is at the outside of the conductor. The individually insulated copper strands are basically the insulated magnet wires laid in form of cable strands.
Kraft paper insulation is most commonly used in oil-filled transformers. The plain kraft papers are wrapped in a number of layers around conductors, to acquire the needed insulation strength. However, plain kraft paper has limitations of the flexibility and leads to breakage of insulation in tight shaping of the coils. For this purpose, kraft papers are fabricated or creped. The folds made in creping process, increases the elasticity and flexibility during shaping of coils. It also enlarges t