| 摘要 |
PURPOSE:To reduce residual magnetization on a cathode ray tube by switching a direction of a resonance current in 1st and 2nd resonance circuits alternately so as to improve unbalance of a positive/negative level of a resonance current. CONSTITUTION:When changeover switches 3a, 3b are thrown to the position of a fixed contact, a resonance current flows in a capacitor 2a, the changeover switch 3a and a degaussing coil by the discharge of a 1st capacitor 2a having been charged from a DC power supply. The 2nd capacitor 2b is charged for that time. When the changeover switches 3a, 3b are thrown to the opposite fixed contact, a low level resonance current flows in the capacitor 2b, the changeover switch 3b and the degaussing coil 1 by the discharge of the 2nd capacitor 2b in opposite polarity. As a result, the resonance current with excellent balance in the polarity as a whole is fed to the degaussing coil 1 while being in attenuation vibration and the cathode ray tube is efficiently degaussed by a well balanced magnetic field from the degaussing coil 1. |
