It’s not entirely clear why [Advanced Tinkering] needs a 50,000-volt power supply, but given the amount ... To ensure everything stays safe in the high-voltage stage, he took the precaution ...

[GK] spends most of the time so far talking about the high voltage power supply design. For the particular tubes he had on hand he needed +200V, -400V, -550V, and 6.3VAC for the CRT heater.

With more than six billion units sold around the world, TinySwitch ICs are widely used in bias and auxiliary supplies in appliance ... technologies for high-voltage power conversion.