Nixie Driver

Given I have so many other clock projects, when I found my stockpiled IN12 tubes, I decided I wanted to do something different. The IN15 tubes allowed me to do other things like temperature, etc. What I want to do, I’m not sure yet. All I know is I wanted to make something modular and that I could change a few lines of code and make completely different use of the tubes down the road.

Unfortunately for me, I’m a bit late for this. In the past 10-15 years there was an explosion of support in my area of interest but a lot of those resources have dried up.

In my research, I found things like the Exixe – this is exactly what I was looking for, but: sold out. I contacted DekuNukem and was advised that because of the chip shortage, availability has waned and prices have skyrocketed. These $13usd drivers are not likely coming around anytime soon.

I managed to find others, but nothing was quite right – or too ‘polished’ and thus expensive, vis-a-vis the https://nixietester.com/ offerings – very well done, but almost too refined for my taste.

In my frustration with trying to find something I could cobble together I finally decided – there is a plethora of resource schematics and data sheets – there isn’t much to driving these tubes, maybe I should just learn PCB design and build my own drivers. JLCPCB was offering 20 boards for ~$10usd + shipping. SparkFun has a great course on Eagle CAD and it is free for tinkerers.

While pulling up schematic resources I came across an instructible for a modular board layout, which included albeit old ARdunio code and Eagle schematics. The parent sites Ogilumen and Lumenspar.com were long offline – in fact, the WayBack machine didn’t have many archives of these sites to choose from.

In my excitement with this find, I decided to head over to JLCPCB but they require Gerber files which were not included. I needed to use Eagle to convert. Fortunately, JLCPCB has tutorials on how to do this. Unfortunately, the BRD\SCH files were from an older version of Eagle and have a few errors that need to be corrected before I can generate the Gerber file. Problem is – the BRD/SCH has more layers than the free version of Eagle supports – and I don’t want to pay the $600+cad that Eagle requires to get a licensed version. I did find a comment on the Instructible from 2021 indicating the author would be looking at updating the code – hopefully, he’s done this and will post the new code soon.

In the interim, I decided to start locating the components.

Buying the components

I ended up finding a supplier “RadioTubeShop” on Etsy (of all places, never shopped there before!) with decent prices. Because the prices were low enough I decided to get some extra parts. Prices without shipping, need based on 3 driver modules:

Order QTYProject NeedPartVendorPrice/ea USD
264 x IN-12/15 SocketsRadioTubeShop$4.40
2610 x K155ID1 Tube Driver ICsRadioTubeShop$5.84
122 x IN-15A + 2 x IN=15B TubesRadioTubeShop$6.00
1920 x 16 DIP IC SocketseBay: youci_2019$2.20
165 x 40 Pin Right Angle Header Pins, 2.54mm pitch, cut to length (6 x 6 pins)eBay: newdeparture2020$1.99
1620 x 6 Pin Right Angle Female Header, 2.54mm pitcheBay: xiumeche-0$1.35
20612 Pin Female Header, 2.54mm pitch (need 6)eBay: kingelectronics15$4.12
106Male Header, 2.54mm pitch, cut to length (6×12 pins)Likely have this
eBay: jagen1shan
$2.60
1320 x SN74HC595N 8bit Shift RegisterseBay: ebest-chips$1.56
1620 x 47k 1w ResistoreBay: umstar1$0.99
103100uF electrolytic capacitor 250v (35v would be fine)eBay: jinwwe-0$3.59
1030.1uF metal film capacitor 630v (35v would be fine)eBay: youci_2019$1.15
11HV Power SupplyeBay: trcorp$13.13
203Nixie BoardJLCPCB$4.95
203Driver BoardJLCPCB$4.95
SUBTOTAL

Boards Ordered!

I finally ordered the boards. I ordered them pretty much as designed. I had to make a few tweaks to get the files to load and ignore some overlap warnings. I reviewed the CAM output and it appears to have processed the BRD files as intended. Time will tell if I did this right…

Power Supply

I decided to get a 12v in, 5v and 80-180v out power supply. This would allow for one input with an output to feed to driver boards AND the tubes. I ended up supporting a Ukrainian supplier.

Now we wait…

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