Crt Clock — Schematic

Prototype the deflection amp on a breadboard, test with a function generator (X=triangle, Y=sine for Lissajous), then integrate the digital control.

void main_loop() while(1) struct time t = RTC_get_time(); draw_digit(t.hours/10, -30, 0); draw_digit(t.hours%10, 0, 0); draw_colon(30, 0); draw_digit(t.mins/10, 60, 0); draw_digit(t.mins%10, 90, 0);

1. Introduction Most digital clocks use 7-segment LEDs or LCD panels. This project takes a different path: using a Cathode Ray Tube (CRT) as the display device. By driving the deflection coils (or plates) with precise analog waveforms, we draw the digits of a clock directly on the phosphor screen.