Magnet wire or enamelled wire is a copper or aluminium wire coated with a very thin layer of insulation. It is used in the construction of transformers, inductors, motors, speakers, hard disk head actuators, potentiometers, electromagnets, and other applications which require tight coils of wire.
The wire itself is most often fully annealed, electrolytically refined copper. Aluminium magnet wire is sometimes used for large transformers and motors,, an aluminium wire must have 1.6 times the cross sectional area as a copper wire to achieve comparable DC resistance. Due to this, copper magnet wires contribute to improving energy efficiency in equipment such as electric motors. For further information, see: Copper in energy efficient motors and Copper wire and cable: magnet wire (Winding wire).
Smaller diameter magnet wire usually has a round cross section. This kind of wire is used for things such as electric guitar pickups. Thicker magnet wire is often square or rectangular (with rounded corners) to provide more current flow per coil length.
- link