This is the brain. You do not store the entire clock face in memory; you store a look-up table (LUT) of coordinates.
This is the trickiest part of the CRT Clock Schematic. You need to move the beam exactly where you want it.
Let’s walk through a complete, proven schematic available on GitHub (search "TinyScope Clock" or "TubeClock V4"). Crt Clock Schematic
The CRT clock schematic is an exercise in hybrid analog-digital design. While modern TFT displays are simpler, the CRT's glowing green phosphor and analog vector movement provide a unique aesthetic. The critical challenges are designing a high-voltage, high-speed deflection amplifier and correctly timing the Z-axis blanking. The resulting device acts as a fully functional clock and an oscilloscope-like display for vector graphics.
Every CRT clock schematic divides into four functional blocks: This is the brain
| Block | Purpose | |-------|---------| | High Voltage (HV) Supply | Generates ~1kV to 15kV for anode acceleration | | Deflection Circuit | Moves the electron beam (X/Y coils or plates) | | Z-axis (Intensity) Control | Turns the beam on/off to draw dots and lines | | Microcontroller & RTC | Generates timing signals and keeps real-time |
Note: Some designs use a magnetic deflection yoke (TV tube), others use electrostatic deflection (oscilloscope tube). We’ll focus on the more maker-friendly electrostatic type. Note: Some designs use a magnetic deflection yoke
Author: AI Research Desk Date: April 13, 2026 Subject: Embedded Systems / Retro Computing