Crt Clock Schematic -

Note: Old TV tubes require 15kV. Do not use TV tubes for desk clocks.

A deep look at a CRT clock schematic reveals a sophisticated interplay of high-voltage engineering and precise timing: Crt Clock Schematic

// Lookup table for digit '0' int zero[5][2] = 0,0, 10,0, 10,20, 0,20, 0,0; Note: Old TV tubes require 15kV

A CRT is a vacuum capacitor. The anode cap requires +500V to +2kV (for small tubes) to accelerate electrons toward the screen. Crt Clock Schematic