Crt Clock Schematic [extra Quality] Info

[ Power Supply Block ] ---> (Low Voltage & High Voltage DC) | v [ Microcontroller/DAC ] ---> [ X/Y Deflection Amplifiers ] ---> [ CRT Yoke/Plates ] | v [ Z-Axis Blanking Circuit ] ---> [ CRT Grid 1 (G1) ]

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

Below is the schematic topology for one deflection axis (X or Y) using a high-voltage operational amplifier configuration:

5V or 3.3V DC for the microcontroller and real-time clock (RTC).

Your schematic must include a bleeder resistor (10MΩ) across the HV capacitor to discharge the tube when power is removed. Without it, the tube holds a lethal charge for weeks. Crt Clock Schematic

Do not use a 555 timer into a MOSFET for this. Royer topology is self-resonant and much cleaner for clock applications.

-1050V DC (variable relative to the cathode). Focus Grid: -800V DC (variable).

Building one is a challenging but rewarding project, requiring a deep understanding of high-voltage circuitry, magnetic or electrostatic deflection, and microcontroller programming. 1. What is a CRT Clock Schematic?

When drafting your schematic, component ratings are highly critical due to the presence of high voltage. Circuit Area Component Type Recommended Spec / Part Number Switching MOSFET IRF840 or CoolMOS (500V-800V rating) Drives the inductor/flyback transformer HV Multiplier UF4007 (Ultra-fast, 1000V, 1A) Rectifies high-frequency HV spikes HV Smoothing Capacitors Ceramic Disc or Polypropylene (1kV - 2kV) Filters ripple out of the anode supply Deflection BJT Transistors MJE340 (NPN) & MJE350 (PNP) High-voltage video amplification Timekeeping Temperature-compensated clock 4. Safety and Troubleshooting Guidelines [ Power Supply Block ] ---> (Low Voltage

You need two identical copies of this circuit: one for X (horizontal) and one for Y (vertical).

However, a CRT cannot display numbers natively. Therefore, the schematic includes a —historically a ROM chip like the 2513, but in modern designs, part of the microcontroller’s code. This logic translates the binary time data into vector or raster coordinates. For a vector CRT clock, the microcontroller outputs analog voltage levels (via digital-to-analog converters or resistor ladders) corresponding to the lines that form each digit.

A , often referred to as an "oscilloscope clock," repurposes a small vacuum tube display to show time as a vector graphic. Unlike modern screens that refresh lines of pixels, a CRT clock uses an electron beam to "draw" the clock face and hands directly onto a phosphorescent screen. Key Components of a CRT Clock

Amplifies low-voltage DAC signals to the high voltages required to move the electron beam. Your schematic must include a bleeder resistor (10MΩ)

Building a Custom Clock with Rare 1EP1 and 1EP11 CRTs - Facebook