If At First You Don't Succeed... Full-On FranLab!!!! Monster VFDs Pt 2

filament current and anode voltages.

Fran Blanche

Unfortunately the VFD's have no diagonal segments for the N's. :(

GrayRaceCat

I built something similar a few years ago using similar but slightly smaller displays. It used an ESP32 processor, which synchronised itself to an atomic clock over the internet, and HV5812 VFD drivers, each of which can drive two VFD tubes. The filaments were driven off 3.2v DC for simplicity. There is a slight gradient in brightness, but it's hardly noticable in use. The whole thing runs off a 5V 2A USB supply (just!) Photos and video: https://photos.app.goo.gl/zt1pQsAgV1D4Dqmv7

Gary Bleads

I'm curious why it's advantageous to run all the heaters in series rather than in parallel. My first thought was that series would suck if one filament burned out and the whole clock went dark, but I guess you'd have to fix it either way so it doesn't matter too much. But I assume there's some other factor I'm not thinking of that makes series wiring make sense - anyone know?

Circuitmike

Hi Fran: When I saw Part 1 I thought to ask you to check to see if you needed a passive pull down for the off segments. It did not occur to me that you would need a hard active pull-down(away). I envision now an active FRANLAB clock where it switches between time HHMMSSX (X=A for am, P= for PM) and FRANLAB.

Donald J Arndt

Just watched on the YouTubes, very cool. Also just signed on to the patreon thing, which brings me to a question: Are schematics and/or code published for big builds, like the clock noted here? I think I have a perfect spot for a ridiculously huge clock like this.

...apply more voltage? Or is that just ElectroBoom?

Chris Crowther

Heyyyyy, ya did it!

Great Joe

Nice work! That's going to be a beautiful clock. All those discrete transistors have me thinking that there must still be a through-hole driver chip somewhere that would make wiring easier. I found a possible starting point for a more thorough search at https://charlesouweland.wordpress.com/2017/12/27/overview-of-driver-ics-for-vfd-displays/.

Great to see you got those beauties working.

David Blake

Hi Fran ! Is this large transformer needed to power the clock (and why) or was this just one that matches (supersedes) and you had already in your storage ?

Anxious to see the clock!

I knew you wouldn't give up that easily. Nice catch on needing to sink to off segments to ground.

Nothing succeeds as planned. Most people take that to mean "Nothing succeeds," but you've shown us otherwise. Eager to see the clock you build with these VFDs.

Dave Land

Never give up, never surrender! This is going to be an amazing clock.

David Peaker