Card-type apparatus and method for generating zero magnetic field

摘要

Card-type apparatus and method for generating a zero magnetic field are disclosed. The generator includes a printed wiring board and a pair of spiral circuits located at corresponding locations on the front and rear sides of the printed wiring board. The winding directions of the spirals are opposite to each other for generating mutually canceling magnetic fields, i.e. a zero magnetic field, upon application of electric current. A through hole is provided through the printed wiring board for connecting the spiral circuits, and a pair of power terminals are provided on the printed wiring board for supplying power to the spiral circuits.