The switched-mode part of the PSU generates the +5V rail for the common digital circuits. The C122 thyristor isn't part of the regulator but a crowbar device safeguarding the +5V power rail against overvoltages. And watch the neat grinding line straight through the ground plane…
The switched-mode part of the PSU generates the +5V rail for the common digital circuits. The C122 thyristor isn't part of the regulator but a crowbar device safeguarding the +5V power rail against overvoltages. And watch the neat grinding line straight through the ground plane…