Signal processor for beam-scan velocity modulation

Abstract

In a signal processor for a beam-scan velocity modulation system in a color TV receiver, a video signal derived from the receiver's luminance channel (or from a combination of the color signal inputs to the receiver's kinescope drivers) is applied to a CR differentiator. Differentiator output is applied to the base of a first transistor disposed with a second transistor to form a first differential amplifier, and to the base of a third transistor disposed with a fourth transistor to form a second differential amplifier. Common load circuit for double-ended limiter formed by the two amplifiers is coupled to collectors of third and fourth transistors. Base bias for second transistor is positively offset from common base bias for first and third transistors, while base bias for fourth transistor is negatively offset therefrom. Output stage of processor, responsive to voltage across common load circuit, drives auxiliary deflection coils via coupling capacitor, which exhibits series resonance with coils at frequency in midband of video signal frequency range.