r/nixie

The nice thing about birthday’s as adults is picking your own present!

Sure, you will loose the element of surprise, but let’s face it, isn’t a “non-surprise” gift, even to yourself, still worth a smile?

My big day is next week, or a week after that, who knows? Who cares?

So forgive me for opening this one a little early.

I’m thinking Nixie clock, right?

I ordered the clock board on AliExpress. The clock has such a gorgeous lamp; any lamp lover should have one!

Hello everyone! About 2 months ago I made a post asking for tips on how to build a VFD clock, and after prototyping on a breadboard, designing a custom PCB, and soldering it all together, here's the finished result! This is my first real personal project as a new EE major and I'm thrilled with how it turned out.

The clock runs on an Arduino Nano Every with 6x daisy-chained 74HC595 shift registers and UDN2981A high-voltage source drivers, one pair per tube. The anode and grid rails run at 25V from a boost converter, and the filament runs at 1.5V from a buck converter, all from a single 5V USB supply.

A full writeup covering design decisions, schematic, and PCB layout is on my GitHub Repo. Stars are appreciated! :)

Thanks to everyone who helped two months ago!

not nixie but adjacent, 6 band analyser taking input from a microphone, compression and analysis done by a pipico, heavily inspired by the EM800 Magilyzer

Another BAD day here, second IN-17 to fail. The first was several weeks ago, and these two were in completely different builds.

In each case one digit (cathode) fails to light, but the other nine work properly.

It’s a MUX drive scheme and three tubes are in parallel, but only one of the three fails.

It is not the solder or lead out wire, and on closer inspection under the microscope it is an internal short. In both dead tubes the same cathode (digit six) is the only failure.

The short is about 1K5 between the cathode and anode leads.

The root cause is an insulation break where the internal connection ribbon passes over a mica insulator and over the edge of the metal frame. The frame connects to the anode.

I have not cut (opened) the tubes, in fact one is still soldered to the PCB, and will take some effort to remove and install a replacement without further damage.

Anyone else have a Nixie horror story, or any insight into this problem?

I've recently setup a few clocks in my office at work. From left to right, IN-8 fine mesh, IN-12, IN-16 (nixiediy kit), and IN-14. In thinking about building an IN-18 next, but may go for an inixie clock instead.

It’s been a year in the making, but she’s finally back up and running! 😍

Huge thanks to u/SignificanceNo4643 for the incredible work on this PCB—and for the patience every time I came back with “just one more tweak” to the firmware. 😂

Somewhere along the way, this turned into a great friendship, and I’m really grateful for that. Looking forward to the next project!

When looking for tiny colon neon bulbs a few years ago I found these 3mm bulbs. They're incredibly tiny and ideal for use with IN-2, IN-16, IN-17 tubes. The picture shows an IN-17 tube, a common 5mm (5x13) bulb and the 3mm (3x10) bulb. It's amazing the can produce them this small.

Should you ever need them, search for 3mm neon bulb on eBay or Ali.

This orange plastic filter was part of a 1960s vintage Burroughs Nixie Display.

I took a PIX with and without it laying on top of an IN17 Six tube display.

Did it help? Looking for a way to make these little Nixies easier to read.

Comments welcome.

I keep these on my bench as a reminder that Nixies are glass and fragile.

I’ve hunted down smaller neon bulbs, to improve the appearance of Colon markers between Nixie tubes (small IN-17 top view type)

The smallest ones look much better than the previous effort.

The generic name for all of these neon bulbs is “NE-2”, although they vary quite a bit in size of the glass and length of the electrodes.

There is probably variation in the gas fill pressure, and mixture (doubtful it is pure neon gas)

I didn’t keep very good records of when and where I got these, although at least one was in a Mouser labeled bag.

Stating the obvious, running any neon bulb from DC is allowed, but doing so only one electrode (the negative or cathode) will glow.

There’s a workaround for this, that lights both electrodes, which I’ll share later.

Do you like the new (small) or old type neon bulb colons in this application?

Just completed a six digit Nixie clock tube testing fixture on a protoboard.

The goal is to have a way to power up and test different nixie tube types by swapping the plug-in PCB module that carries the tubes.

Although the idea was to just run through all numbers (cathodes) for testing, and possibly for “burn in” to repair any failed digit glow, adding an RTC made it into a functional clock.

These are Burroughs B5885 Nixies salvaged from a 1970s calculator (I think, I just got the hacked up PCB with the tubes still attached)

I made a similar PCB for Russian Nixies, one for IN-16 side view and another for IN-17 top view types.

What do you think?

I can post more PIX or details if there’s interest.

Turns out that the non-lighting IN-17, that might have had an internal short, was a red herring.

On closer inspection I found that all three Nixies on the same bus had a missing “six”.

There was an intermittent failed soldering on the driver IC. Hard to notice this without using a microscope!

I still have the original IN-17 with a “Six” short.

To check Nixie operation I can run a test that uses the rotary encoder to scan through digits and also select which Nixie to drive.

A couple of hours lost today, but a good learning experience.

Comments Welcome,

This build has twin neons for digit separators.

I’m wondering if these neons are bit too big to be next to the tiny IN17 top reading Nixies?

Should I look for smaller neons for this one?

Let me know your thoughts.

Probably need a “blue cut” optical filter here to knock down the UV from the mercury glow?

Any suggestions on what filter material to use?

I’ve seen red or orange tinted material used in some of the earlier Nixie display frames.

The iOS camera (most phone cameras?) pick up that bluish tint from raw glass Nixies.

To test the completed PCBs here’s a hand wired prototype circuit board.

The Nixie tubes are attached to their PCB, which is in turn plugged into this “motherboard” for testing.

There are support circuits on the motherboard including the three discrete high voltage switches that drive the Anodes for MUX, an RTC module for time data, a rotary encoder for manual digit selection, and a status LED bar graph. High voltages come from the HVPSU module shown in another post.

A Microchip/Atmel Atmega 328 MCU provides timing and control, and has the minimalistic hardware for uploading firmware during development and testing.

What do you think of this set up?

Bought these 3x calculators from the thrift store and pulled out their boards w/ the VFDs attached. These 3 all use different VFDs. Paid $21, which I figured was worth the experience. I got 3x transformers as well which is a plus.

SHARP EL-2630P: Futuba 13-LT-48GNYM

This one has the biggest ones so I'm most interested in driving these. The board comes with 3x M54531P transistor arrays which could definitely be helpful.

SHARP EL-1801P: Futuba 13-LT-63N

This one was the brightest at the thrift store. The board has no ICs which I can use.

Canon MP11DX: ????

This one seems most advanced, and has a ton of useful ICs. There are 3x ULN2003 transistor arrays, and 2x 74HC373D Octal D-type latches. I'm not sure which VFD this one uses.

Have any of y'all figured out how to drive these? Any info would be appreciated.

Thanks! :)

Continuing my experiments to compare different Nixie tube’s appearance I created some PCBs.

For the small tubes I set the tube spacing for a six digit array, with neon spacers between HH, MM, and SS pairs.

The three Nixe types that have been installed are:

Burroughs B5885 (side view)

Gazotron IN-16 (side view)

Gazotron IN-17 (top view)

The single driver IC and anode resistors are on the backside, due to limited PCB space.

Six tubes are MUX’d with three Anode high-side switches, on the mother board (not shown in this post)

Another PCB has been fabbed for six medium tubes, Gazotron IN8-2, and is being assembled.

This uses direct drive with three cathode driver ICs, on the PCB, each connected to a pair of tubes.

What do you think of these?

To power my various Nixie projects I created a HVPSU module.

Running from 12V DC it delivers a 180V Rail for the Anodes, a 60V Rail for the Nixie driver ICs, 5V for the RTC module and the MCU.

The build uses a mix of THT and SMT parts.

This is a hand assembly, using a Pizza oven for the mass soldering of SMT parts, which requires two passes starting with the parts on the backside.

For the first batch I used a syringe to “dot” solder paste and tweezers for pick and place.

What do you think?