| 摘要 |
PURPOSE:To modulate a horizontal amplitude in a vertical deflection cycle and in an accurate and optional waveform, by giving wave detection to the voltage produced at both ends of an S-shaped correction capacitor connected in series to a horizontal deflection coil and therefore detecting only the modulated wave component. CONSTITUTION:An S-shaped correction capacitor Cs, i.e., a capacitor 17 is used in place of a current/voltage conversion resistance serving as a detection resistance. Thus about a >=10-fold voltage level is obtained as a parabolic wave voltage W1. Then an operational amplifier 9 can be actuated under the ideal conditions. While a Zener diode 18 shown in the figure is connected in series to either one of two diodes 13 in the direction shown in the figure. Thus only the DC voltage is reduced by an amount equal to the Zener voltage component. This can reduce breakdown strength of a coupling capacitor 16. The diode 18 can be connected in series to a diode 12 as well as the diode 13 and then to both diodes at a time. |
