Computers and smartphones have done away with the need for many things that we used to rely on, like standalone GPS navigators, MP3 players, and physical address books. But one device that people are nowhere near ready to give up — despite it becoming technically obsolete — is the desk clock. It doesn’t matter how convenient it is to check the time on our phones or taskbars, we still love our clocks and we aren’t getting rid of them.
And why should we? A good clock does more than just tell the time; it is a decoration — a work of art, even. Consider Aron Szucs’ custom clock called the IV-11 VFD Tube Clock. It’s beautiful! No matter how you arrange the pixels on an LCD display, they will never have the charm of this clock. And fortunately for us, Szucs has provided enough details for anyone to be able to build their own IV-11.
The circuit diagram (📷: Aron Szucs)
At the heart of this build are six Soviet-era IV-11 vacuum fluorescent display (VFD) tubes, originally manufactured in Ukraine during the 1970s and 1980s. These vintage components give the clock its signature glow, but the project itself is anything but outdated. Designed entirely from scratch, the clock combines modern electronics with retro aesthetics.
Unlike many VFD projects that rely on multiplexing to reduce component count, Szucs opted for a static drive configuration. Each tube is powered continuously at full brightness, controlled by its own pair of shift register and high-voltage driver chips. While this approach increases hardware complexity, it results in a noticeably brighter and more stable display, free from flicker and timing artifacts.
Power management is handled through a dual-converter setup. A boost converter steps a standard 5V USB input up to 25V for the tube anodes and grids, while a buck converter drops the voltage down to 1.5V for the filaments. Timekeeping is maintained by a highly accurate real-time clock module, ensuring the device loses less than a minute per year even when unplugged, thanks to a small backup battery.
The clock’s custom circuit board (📷: Aron Szucs)
The brain of the operation is an Arduino Nano Every that coordinates everything from display updates to user input. Szucs implemented a seven-state finite state machine to handle all interactions, including time setting, brightness control, and switching between 12- and 24-hour formats. A particularly elegant feature is the brightness adjustment system, which uses pulse-width modulation on the shift registers’ output enable pin to smoothly dim the display — even automatically based on the time of day.
With a total cost under $90 and publicly available design files, the IV-11 VFD Tube Clock would make for a great weekend project if you are looking for a new clock, or just a great conversation piece. Check out the project’s GitHub repository for more details.
