Editing Polyphase coil (section)

{{Unreferenced|date=December 2009}}
'''Polyphase coils''' are [[electromagnetic coil]]s  connected together in a [[polyphase system]] such as a [[electrical generator|generator]] or [[electric motor|motor]].  In modern systems, the number of phases is usually three or a multiple of three. Each phase carries a sinusoidal [[alternating current]] whose [[phase (waves)|phase]] is delayed relative to one of its neighbours and advanced relative to its other neighbour. The phase currents are separated in time evenly within each period of the alternating current. For example, in a three-phase system, the phases are separated from each other by one-third of the period.