EEVblog #950 - Nixie Tube Display Project - Part 2

Some more info and experiments on driving Nixie tubes.
Open circuit cathode voltage, open collector vs totem pole / push-pull drivers, NIxie voltage drop and pre-biasing, and using the ULN2003 with zener clamping.

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[JackZimmermann]

I love this "follow along" format! Seeing how you decide on solutions is great! More project videos.

[philippstocker]

You should have done a nixie live subscription counter

[virtualassistant]

Dave, Thank you for doing another "Project video". By far this is my favorite type of you videos. I love seeing you go through the process of designing something.
Please do more videos of you creating things from scratch.

[TheRealBobHickman]

A great application of electronics theory to the design of a practical application. It's great to follow along with your decision making process and the possible pitfalls (with tests). I'm starting to feel like I comprehend this better. Really great so far, looking forward to part 3. Thanks Dave!

[bohdanked]

Shortly after this video came out, a bunch of Chinese makers started to sell nixie clocks based on this ULN2003 design. Prior they used more expensive HV serial to parallel chips.

[tonybell]

Cheers Dave, thoroughly enjoying this series, real world design issues discussed during a project superb....

[ElectraFlarefire]

Not a single rant or hate at Jaycar or indeed any other company!
Makes a great change and a very enjoyable video. Interesting subject covered in good detail.

[uNails]

Wow! Over my head, but I really enjoyed watching you work through the design and test some here. I don't have any experience in this area, but it's truly fascinating.

[whx]

there are millions of these 74141 chips available on ebay. It saves so much time and headache. They are designed to simplify all of this. I would definitely go that route much much simpler! And one benefit of some of these '141 is that they can handle blanking the any leading zeros. Useful

[IgnazKevenaar]

This is great. I have some IN-12b laying around myself and wondered about a good way of driving them. Absolutely will keep a close eye on these videos. Please keep them coming!

[KennethScharf]

Open circuit voltage drop depends on how close the element in question is to another element that is switched on.

[therealjammit]

You can add a diode to the output to a totem pole to create a pseudo open collector/drain output.

[JerryWalker]

Hi Dave, interesting project. I worked on a spectrophotometer design in the late 70's which used an 8008 processor and had a nixie tube display. We used a similar arrangement to the one you showed except that we used discrete transistors and steering diodes for the drivers. However we did find a relatively easy way to strobe the digits. Each was fed from the +HV supply via its own resistor and we used high voltage (200V) transistors to pull the tube common to ground except the one that was 'on'. It was a 6 digit display so we did not need may of the expensive high voltage devices. This worked well although the resistors used to get fairly hot.

[NorbertHarrer]

Dave is building experimenting with a lot of stuff lately. I love it ;-D

[Petex]

Quite neat solution to use the zener diode & pre-bias! Enjoying these design videos :)

[kaizen]

Very good video Dave. This series is excellent.

[SuperZylar]

my tubes are drive by MMBTA92 and MMBTA42 in Darlington another MMBTA42 for selecting and indeed clamped to ground with an in4148 diode and a 47k 47k trough an voltage divider

[stabilini]

great videos Dave... there is a lot of learning only hearing your thougts and design tests

[OneBiOzZ]

Why not just leave the HV pin floating in the push pull?

[rocketmanprojects]

If you got an IN-15A and IN-15B nixie tube, you could make a nice multimeter with them. They are identical to the IN-12 but contain the symbols for different units instead of digits.