module for high accuracy, or sync via Wi-Fi (NTP) if using an ESP32. Signal Generation (X-Y Deflection)
Building a CRT Clock: Complete Schematic Guide, Architecture, and Design Theory
Before we read the schematic, let’s visualize the signal flow. A typical vector-based CRT clock (e.g., the infamous "Vyzkum" or "Joule" designs) consists of five core subsystems:
Put small 100-ohm series resistors on the outputs of the deflection amplifiers to eliminate high-frequency ringing on the vector lines. 4. Firmware Logic and Drawing Vectors Crt Clock Schematic
: Components like EF80 vacuum tubes or high-voltage transistors (e.g., ZTX458 ) that amplify signal voltages to the levels needed by the CRT deflection plates. CRT Tube : Popular 2-inch and 3-inch models include the , , and .
A CRT clock is a functional piece of kinetic art. By removing the internal sweep circuits of a standard oscilloscope or a small CRT (such as a 3RP1A or 5BP1), an external microcontroller can drive the deflection plates directly. This schematic focuses on generating lines and characters using the "analog vector" method rather than digital pixel mapping.
Building a functional CRT clock requires four primary circuit blocks: the power supply, the timekeeping engine, the vector generation circuit, and the blanking amplifier. High-Voltage Power Supply (HVPS) Circuit module for high accuracy, or sync via Wi-Fi
Never connect a CRT clock directly to mains electricity without an isolation transformer. Most schematics assume an isolated 12V DC wall-wart input, which is then stepped up internally.
Outputs voltage corresponding to the horizontal position of the beam.
Most reliable schematics use the following chain: A CRT clock is a functional piece of kinetic art
Outputs voltage corresponding to the vertical position of the beam.
Instead of high voltage, these tubes require high current driven through external copper coils (yoke). The schematic here utilizes heavy-duty audio power amplifier ICs (like the LM386 for tiny tubes or TDA-series chips for larger ones) configured as constant-current drivers. Section C: High-Voltage Power Supply (HVPS)
// Draw Minute Hand points[62] = 0, 0, Z_OFF; points[63] = sin(angle_m)*0.6, cos(angle_m)*0.6, Z_ON;