Reddit user [InThePartsBin] found some VFDs (Vacuum Fluorescent Displays) on an old PCB on eBay. The Russian boards date from 1987 and have a bunch of through-hole resistors, transistors and a some mystery ICs, plastic wraps around the legs and the top of the tube is held steady by a rubber grommet (the tip itself goes through a hole in a board mounted perpendicular to the main board.) Being the curious kind of person we like, and seeing the boards weren’t too expensive, he bought some in order to play around with to see if he could bring them back to life.
After getting the VFDs lighting up and figuring out the circuitry on the back, [InThePartsBin] decided that a clock was the best thing to build out of it. It was decided that a specialized VFD driver chip was the easiest way to make the thing work, so a MAX6934 was ordered. To give the clock some brains, an ATmega328 was recruited and to keep time, [InThePartsBin] had some DS3231 real-time clock modules left over from a previous project, so they were recruited as well. A daughterboard was designed to sit on the back of the vintage board and hold the ‘328 and the VFD driver chip.
Once [InThePartsBin] soldered on the components it was time to fire it up and send 1’s to the driver to turn on all the segments on all the tubes. Success! The only thing that [InThePartsBin] has left to do is write the code for the clock, but all the segments and tubes are controllable now, so the hardware part is done. There are other VFD clock projects on the site: Check out this one, or this one, and bask in the beautiful steel-blue glow.
Via Reddit.
The К155ЛА3 was the Soviet equivalent of a 74’00.
Can’t see enough detail to figure out why it’s there.
1987 is vintage now? I was a teenager in 1987! Dang, I guess I really am getting old!
No, wait: I’m vintage!
Hmm…
Let me just check my expiry date…
Oh Shit……………………………
Dang. Thought this was about VFD (variable frequency drive) not VTFD (“Nixie tube”)
VFD (Vacuum Fluorscent Display) and Nixie Tubes are two different things. Not the same technology at all.
The kind of person who decides that they need to invent a brand new acronym to rationalize their disappointment that this isn’t the thing they want it to be isn’t the kind of person who cares whether the glass envelope is filled with neon or vacuum.
Well, a variable frequency drive (VFD) is a thing. It’s actually why I clicked as well. They’re used in large AC motor applications like HVAC air handlers where variable air volume is required.
No-one called a Vacuum Fluorescent Display a VTFD. Ever. Until just now, where todd3465 invented a new acronym.
I get wanting to disambiguate between the two expansions of VFD, but to actually usefully disambiguate you don’t get to move just one. The motor driver context fortunately already has half a dozen pre-established acronyms that are not VFD.