Circuit device for generating a grid on a screen of an electron beam tube, with means for generating a line-frequent and parabolically modulated particle-image-frequency saw-tooth current in an image-displacement coil

摘要

A TV deflection system that includes a circuit for generating a sawtooth field current parabolically modulated at the line frequency in the field deflection coil. The circuit includes a resonant circuit composed of a capacitor and the field deflection coil with a resonant frequency that is approximately one fifth of the line frequency for deriving the parabolic modulation component of line frequency. The sawtooth field deflection generator periodically excites the resonant circuit via a bidirectional electronic switch that is periodically switched in synchronism with the line flyback pulses.