Which is the best Numitron driver IC

Hi @BDub,

I wonder if you could give me some advice. I was lucky enough to be given four Numitron tubes the other day and I was wondering what you would have considered to be the best IC to drive them?

I was thinking of a TPIC6B595N because it can handle the current that is required to get an incandescent tube running, I have also considered the ULN 2803?

Any comments / suggestions / improvements would be welcome.



Wow I never owned such tubes/nixie etc.

Would love to see it in action!

1 Like

Hi @kennethlimcp, yes they look brilliant don’t they. I was at my local FabLab on Saturday and a chap gave me four to play with. (Am I lucky, or what!). I just need to get them working with a spark core.

Sort of retro, steampunk?

1 Like

Julian, a project on hackaday with Numitrons used a LED driver since they provide a nice constant current drive. Will you be multiplexing the tubes? If so, you could use NPN transistors to drive each tube filament. Instructables has a clock project you could look at for inspiration. :smile:

1 Like

Wow. 2 nixie tube posts within an hour or two of each other on the same day. One of these days, I’m going to put together a nixie tube display. There are a lot of cheap ones on eBay from Ukraine and Russia. Which side of the conflict are they funding?!

Hi @peekay123, You are totally on the money with the instructable. When I was given the tubes, I knew exactly what I wanted to do with them, went looking for an instructable and found the one you have linked to. I have the enclosure laser cut out of white perspex and ready to go.

Right now I just want to get some of the segments lit in a test rig. do you have any ideas how I might do that?

then a PCB design including a spark core…


Hey @wgbartley, nixie tubes are very similar to look at but quite different to use. Don’t ask me the exact ins and outs but the Nixie tubes take more power to run than numitron tubes and so are less suitable to run from a micro controller.

Julia, nixie tubes work at a higher voltage because unlike Numitrons which use light filaments and operate at lower voltates (typically 12V), nixies use neon (or other rare gas) to emit colors. You need at least 90V (if I recall) for neon to start emitting. :smile:

The biggest difference between Numitron tubes vs. Nixie tubes is that they only take 1.5 - 5VDC to operate, vs. 170VDC for Nixie tubes :wink: All Numitrons are not created equally, so you should probably get the datasheet for it to know for sure.

1 Like

@BDub I have a data sheet but it is in …Russian :frowning:

The data sheet is here http://www.tubeclockdb.com/numitron-tubes/6-iv-9.html

Hmm, I’m totally guessing here… but it looks like 4.5V supply voltage. 19.5mA supply current typical and 3.15V minimum per input to turn on a segment?

1 Like

@BDub, @peekay123 looks like it is the A6278 for me then.

I will give it a try and see what happens!

Julian, only problem is that part is discontinued!

@peekay123, Do you have any ideas for a fall beck position, I have been trying, but as you say the A6278 is defunked! :frowning:

@BDub @peekay123

I have a fall back position, http://www.ti.com/product/tlc5916

as detailed here,


and here,

What do you think chaps?

Julian, from the looks of it, you can daisy chain those controllers for multiple tubes. I’m sure we can find sample code somewhere and port it over to the Spark. :smile:

@peekay123, thank you for your very generous offer to help with some code! :slight_smile:

I was going to try to use the @bko RTC code. Four tubes two for hours, two for minutes.

. I have made an enclosure like this one:-

I have a couple of the TLC5916 chips so I am going to have a play and see if I can get them running.

Do you have any suggestions for a simple trial code?

Julian, I’ll try an whip up something quick for a single chip to begin with if that’s ok? Let me know what segments of the numitron you have on which pins.

There is now an undocumented (for now) Time class that can be used with less overhead. A quick hour+minute+second example is:

void setup() {

void loop() {

This Time class availability was mentioned in passing just a few days ago.  I'm going to try and get it documented for a pull request tonight.

&lt;UPDATE&gt; I have documented the Time library and submitted a pull request.  Hopefully the update (240 lines) will be approved and show up in the official documentation soon! &lt;/UPDATE&gt;
1 Like

@peekay123, Thank you very much. I will put something together asap and let you know how I go on with the pinout.