) placed in parallel with the high-voltage filter capacitors. These safely drain remaining electrical charges when the clock is powered down.
Chips like the MCP4822 or TLV5618 convert the digital coordinates from the MCU into precise X and Y analog voltage signals.
A variable negative voltage (around -20V to -100V) relative to the cathode used to control brightness.
No specific math equations were used, so no $$math syntax$$. Crt Clock Schematic
: Unlike standard pixel-based screens, these clocks draw "continuous" lines, allowing for elegant analog faces, Roman numerals, and even retro games like Pong or Tetris .
Do you prefer a or using an integrated high-voltage op-amp for deflection?
11 Oct 2025 — yeah I think we're think we're down some voltage there or something pretty blurry definitely better so we'll stick with this. too. YouTube·CREEKVIEW ACRES ) placed in parallel with the high-voltage filter capacitors
An LT1210 or a standard high-voltage op-amp handles initial conditioning.
The CRT's heater (filament) typically runs on . While a separate winding on a transformer was common historically, modern designs often use a simple LM317 voltage regulator to derive the 6.3V from a DC supply like 12V. Additional bias voltages (e.g., -1000V for the cathode, +2000V for post-deflection acceleration) may be required for certain tubes.
A cathode-ray tube (CRT) clock is a unique device that uses a CRT—the same technology found in vintage oscilloscopes and televisions—to display the time. Unlike the blocky pixels of an LCD, a CRT clock draws crisp, glowing lines directly on a phosphor screen. These clocks are prized by enthusiasts for their retro-futuristic appearance and the technical elegance of the vector-drawn display. A variable negative voltage (around -20V to -100V)
This is the "brain" of the clock. It generates the precise voltage sequences for the X and Y axes to draw the clock face. Common choices include:
If you are planning to build or troubleshoot a CRT clock circuit, I can help you refine the design. Let me know: What do you plan to use?