摘要 |
RCA 72,161 PINCUSHION CORRECTION CIRCUIT A side pincushion correction circuit is coupled to a horizontal resonant retrace circuit which includes a retrace capacitor and a horizontal deflection winding. The correction circuit includes an inductance and a controllable switch which is turned on during each horizontal retrace interval. A compensating circuit comprising secondary winding of a flyback transformer is coupled to the inductance and reflects the inductance onto the primary winding side in series with the deflection winding when the switch is open circuited and reflects the inductance in parallel with the deflection winding when the switch is conducting. The on-off ratio of the switch during horizontal retrace is modulated at a vertical parabolic rate to achieve side pincushion correction. The turns ratio of the flyback transformer is selected to adjust the resonant frequency and the retrace time modulation created by the correction circuit. |