Circuit for combining AKB and selective beam current limiting and projection television system utilizing same

A projection television system including three separate cathode ray tubes (CRTs) and a video processor with a control circuit including combined automatic kinescope bias (AKB) control circuitry and average individual beam current sensing and limiting in at least one CRT for sensing and limiting an average individual beam current in each of the three separate CRTs, wherein the control circuit comprises:

• 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;
• and
• selective beam current limiting circuitry which compares at least one of the R, G and B average current control signals with a predetermined signal, and whereupon the at least 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 said at least one of the R, G and B average current control signals.