Method and apparatus for magnetic field suppression using inductive resonant and non-resonant passive loops

摘要

The present invention provides an apparatus and methods to reduce the stray magnetic fields created by the yoke assembly of a cathode ray tube (CRT) visual display device, and emitted from the CRT enclosure. A pair of closed wire loops are brought into contact with the yoke at the point where maximum magnetic radiation is emitted. The magnetic flux emitted from the yoke is coupled into the wire loop pair, inducing therein a current which flows so as to produce an opposing magnetic field to that produced by the CRT yoke. A capacitor in series in the second loop serves to increase the magnitude of the magnetic field produced by the second loop. Measured at a distance, the counteracting magnetic field reduces the total magnetic field emitted from the CRT enclosure.