A design of eddy current controller in electron gun using 3D boundary element method

A transient electromagnetic held of the electron gun in color picture tube is analyzed using 3D-boundary element method, and the eddy current controll er is designed to shield the stray field from the magnetic deflection yoke, The stray field from the deflection yoke, which induces an eddy current on the electron gun and brings about the convergence error on the screen amon g the red, green and blue beams, is approximated as saw type field and Four ier transformed to be used as an incident field in the analysis, The bounda ry element formulation is achieved by using the (jw) method. By comparing t he shielding effects of the eddy current controller as increasing the lengt h of the controller, it is shown that the eddy current controller can be de signed optimally.