Thomas Shufps' Clock Turns a Vintage VFD Into a Crisp, Clear Image with an Upcycled Camera Lens
A coincidence between a vintage glowing display and an analog photography format gives rise to a surprisingly simple projector clock.
Maker Thomas Shufps has designed a projector clock for nighttime use — and the first, he claims, to use a vacuum fluorescent display (VFD), having already built one with an LCD panel.
"The VFD Night Projector Clock is the first and only (at the moment and to my knowledge) night projecting clock that uses a VFD display," Shufps claims of his creation, which makes use of a coincidence of sizing between the four-digit clock display and a classic photographic format.
"When receiving one of the NOS IVL2-7/5 displays, I noticed that the illuminated area could fit in about full-format (24x36mm) what was standard in analogue photography," Shufps explains. "For this reason there are plenty of old lenses (e.g. with M42 threading) out there that almost cost nothing any more although they have impressive technical properties like 1:2.8 with f=135."
Predating both LCD and LED displays, VFDs are built using phosphor-coated anodes bombarded with electrons from a cathode filament — operating like a simplified cathode-ray tube (CRT), though at a lower voltage. Offering a high brightness and coming in a range of sizes, VFDs were a staple of electronics until lower-power LEDs and more detailed LCD panels took over.
To turn the vintage VFD display into a clock Shufps built a custom controller board which includes an isolated 24V converter for the anode, a full-bridge rectifier built using a two-channel MOSFET driver, and an STMicro STM32 microcontroller to tie everything together — communicating with a Python program running on a desktop to set the time, control the display state, and measure the clock's accuracy.
To actually project the image on the ceiling, Shufps turned to a vintage camera lens — fitted to a simple cone-shaped 3D-printed adapter to place it at the right distance from the display. "The brightness is perfect in the night," Shufps writes, "but [of course] barely visible at day. If everything is adjusted properly, you even can see the [mesh control] grid on the digits."
The VFD clock is actually Shufps' second shot at nighttime time-telling, after an earlier project which used an LCD panel with a C-mount or E-mount camera lens. As with the original design, Shufps has published design files and source code for the project to GitHub under the permissive MIT license.
