Patent ID: 6535092
Filing Date: 2003-03-18
Classification: C30B,H01F,Y10S

Abstract:
A device for generating a variable composite magnetic field, the device comprising a ring member (2,3) defining a main central axis (5) and a central area (4) around the central axis (5) within which the composite magnetic field is generated, a plurality of discrete magnetic field generating means (18) for generating respective magnetic fields mounted at spaced apart intervals around the ring member (2,3) for generating the composite magnetic field in the central area (4), characterised in that the respective magnetic field generating means (18) are orientably mounted on the ring member (2,3) for varying the orientations of the magnetic fields generated by the magnetic field generating means (18) for varying the composite magnetic field, and a means (22) is provided for varying the orientations of the magnetic field generating means (18) and for retaining the magnetic field generating means (18) in desired orientations.