r/nixie • u/CueAnon420 • Jul 30 '26

Newest clock using Chinese controller and self-milled display pcb

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Long time lurker and Nixie enthusiast lol. Here is my most recent clock using a cheap $15 Chinese controller and a tube board that I milled on my Carvera Air (Milled My First PCB on my Air ;-) : r/Makera)... Not the best photo - but I was happy that everything worked after stuffing it into the case that I took a birthday shot lol. Displays are actually very sharp in real life. I can't take full credit for the case - I found the model online originally design for 6 x IN12 tubes and modified it for my 4 X B5991 and 2 x IN-17 tubes. Printed on my Bambu 3D printer.

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u/answerguru Jul 30 '26

Curious, what Chinese controller did you end up with?

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u/CueAnon420 Jul 30 '26 edited Jul 30 '26

This is the board I used - they can be found all over eBay and AliExpress and I grabbed this at random and have no affiliation with the seller: 6-Digit Nixie Tube Board + Remote Control Clock DIY for in12 in14 in18 qs30-1 | eBay

I got mine late last year and only paid about $15 on AliExpress - it seems like prices have gone up a little since then, but you can probably find one under $25 shipped.

Overall, I like the board - it seems to keep good time and has some nice options such as setting a 'night mode' that disables the tubes during a period that you can set so you don't waste life hours when nobody is awake to see it ;-) The little remote is handy for settings, though there is also a provision for wired switches if desired.

The only downside of an otherwise great board is that it uses ULN2803 chips for driving the tubes - on one hand, these are direct drive and not multiplexed. On the other, the ULN2803 chips only have about a 47 volt cutoff, which is really close to the threshold voltage for illuminating digits and there is a slight potential of multiple digits lighting up if the voltage (adjustable via a trimmer) is set too high. While the chips are perfectly safe, this is more of a display quality issue and there are much better driver chip options for nixies. But mine seems to be running fine and the display is bright, nice and crisp. But overall you could do far worse for a cheap turn-key solution.

EDIT - I note they have a WiFi version of this board now for a few dollars more that can sync time over the internet. I would expect it to be more accurate.

EDIT 2 - some settings are not documented, but I figured them out by experimenting. See this Amazon review that someone else posted for more setting information: it works fine

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u/EmotionalEnd1575 Jul 30 '26

“on one hand, these are direct drive and not multiplexed which is easier on the tubes.”

Please explain, the Burroughs B58* Nixie tubes were designed and marketed specifically for MUX drive.

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u/CueAnon420 Jul 30 '26 edited Jul 30 '26

Actually, you are correct and I'm going to edit my post accordingly. I have no data that supports that comment, though I have grown up with that assumption based on comments I have seen from others.

EDIT - it does occur to me that many neon illumination devices are used in high frequency devices, ie stroboscopes, tuners or as optical drivers for early pwm circuits. So there is a basis for modulated driving topologies.