High-Voltage Regulation and Protection Circuits for Solid-State Color Television

It has been comon practice to use high voltage regulation circuits in higher quality color TV sets to improve performance. This was usually done with high voltage shunt regulator tubes which provide the horizontal. scan and high voltage part of the TV set with a constant load regardless of the brightness of the picture. A common problem has been excessive x-radiation when these tubes fail and the high voltage tends to reach very high values at low brightness. Therefore, a number of feedback circuits were designed to make the set conform with the radiation standards in case of a regulator tube failure. Figure 1 shows such a system. The feedback loop is drawn in heavier lines.