| 摘要 |
PURPOSE:To demagnetize a color Braun tube without disturbing a display screen when it is magnetized due to the change of external magnetic field to cause color displacement, by connecting to a demagnetizing current generation circuit, and by using a demagnetizing coil which outputs AC current whose amplitude gradually reduces. CONSTITUTION:An SCR22 is in an open state, and a capacitor 23 is charged through a register 24. If a gated oscillation signal (d) is inputted in a terminal 21, the SCR22 becomes to be in a close state, and an SCR26 controlled by an inverter 25 simultaneously becomes in an open state so that a part of electric charge charged in the capacitor 23 flows current to a demagnetizing coil 12 until a capacitor 27 is completely charged through the demagnetizing coil 12. If the gated oscillation signal (d) becomes to be on a low level, the SCR becomes to be in an open state and the SCR to be in a close state so that the electric charge charged in the capacitor 27 is discharged in a channel between the demagnetizing coil 12 and the SCR26 to cause flow of current in the reverse direction to the demagnetizing coil 12. As the result, one cycle of AC current has flowed to the demagnetizing coil 12. |
