Power on with the DAC set to 0V.
Because CRTs require high voltages (often between 1,000V to 3,000V) to operate, these projects bridge the gap between digital logic and high-voltage analog engineering.
Warning: This section deals with lethal voltages (up to 1kV). Crt Clock Schematic
Usually an Arduino, ESP32, or STM32 that handles timekeeping and generates the X, Y, and Z signals.
A standard CRT clock schematic must solve a difficult engineering puzzle: how to safely control a high-voltage vacuum tube with a modern, low-voltage microcontroller. Power on with the DAC set to 0V
A CRT clock doesn't work like a modern LCD. You aren't turning pixels on and off; you are steering a focused beam of electrons. To create a schematic, you must integrate four distinct systems:
The output from the DAC is only 5V, but the CRT needs roughly 200V-400V of "swing" to move the beam across the screen. Usually an Arduino, ESP32, or STM32 that handles
Start with the low voltage supply. Wire the transformer secondary to a bridge rectifier (1N4007 x4) and a 7812/7912 regulator for bipolar supplies. Do not touch the high voltage side yet.