| 摘要 |
The coils (2,3) fitted to the cathode ray rube (1) have a further coil (6) connected to them which is coupled and wound to produce a magnetic alternating field counter-directed to the interference field produced by the main coils. The further coil is formed as a separate unit which fits alongside the main coils, and has little inductance. It is air-wound or wound on a bobbin comprising electrically insulating material. - The bobbin enables attachment of one or more magnetically conductive parts. A ferrite core (8) is fitted around the throat (1a) of the cathode ray tube, and inside it are located the two main windings series-coupled in the form of saddle coils. Toroid coils may also be used. The coil bobbin also has a holder which can work in conjunction with the outer surface of the ferrite core (8), and has one or more tracks in which the magnetically conductive parts are fitted. |
