Low frequency communication device using magnetic coupling

摘要

An omnidirectional low frequency magnetic field may be produced by first winding a coil (1) on an axis Oy, then winding a coil (3) on an axis Ox. Finally a third coil (2) is wound on an axis Oz. Currents of the same frequency but displaced in phase by 60 or120 degrees are applied to the coils to produce the omnirectional field. The core (4) which has coil slots is preferably made from a material of high permeability in order to maximise field strength