A control circuit for use in a video processor utilizes combined automatic kinescope
bias (AKB) control, and average individual beam current sensing and limiting in
at least one CRT. The control circuit includes automatic kinescope bias (AKB) control
circuitry for detecting a magnitude of individual red (R), green (G) and blue (B)
cathode currents driving corresponding R, G and B CRTs, generating R, G and B average
cathode current control signals therefrom, and using the R, G and B average cathode
current control signals as feedback to the video processor to reduce the R, G and
B cathode currents approximately equal current amounts. Selective beam current
limiting circuitry within the control circuitry compares at least one of the R,
G and B average current control signals with a predetermined signal, and whereupon
the at least one of the R, G and B average current control signals exceeds the
predetermined signal, introducing a gain reduction in corresponding video gain
stages within the video processor to limit the at least one of the R, G and B average
current control signals.
