EEVblog

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.

[@virtualassistant2101]

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.

[@philippstocker2632]

You should have done a nixie live subscription counter

[@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!

[@u9Nails]

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.

[@tonybell1597]

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

[@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!

[@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.

[@Petex90]

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

[@willynebula6193]

nitty gritty video👍 good shit dave👍👍

[@EEVblog]

Thanks.

[@NorbertHarrer]

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

[@w2hx]

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

[@JerryWalker001]

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.

[@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.

[@christiandinkel8481]

Electra Flarefire how very passive aggressive of you ;-) . Got your clamwrap in a twist about something?

[@ElectraFlarefire]

It was not intended that way. Sorry. These are the sort of videos/content that had me watching in the first place and it's a nice to see a return to form.

[@EEVblog]

You could have left out the first sentence.

[@ElectraFlarefire]

I felt the first line was needed as it was intended to convey both what has been annoying in some of the previous videos as well as a big 'Really enjoyed this one'. I could have phrased it better however, that is definitely true.

[@christiandinkel8481]

If you were to put a comment saying "these rants are annoying" on one of the previous videos and put a comment saying "really enjoyed this video" under this one, it would both seem less underhanded and as if you were not holding this much of a grudge. Of course, that might mean someone would respond "Me too, it was great" to this comment and "Just unsubscribe if you don't like the videos any more" to the other one, so maybe that's not what you want. But then again, maybe try not to care so much what perfectly random strangers on the internet think of you.

[@kaizen9451]

Very good video Dave. This series is excellent.

[@stabilini]

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

[@John_Ridley]

Yet again, I watch one of these videos and go to eBay to order parts to keep on hand (ULN2003). I like having plenty of parts on hand to make stuff when I feel like it without having to order stuff.

[@therealjammit]

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

[@KennethScharf]

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

[@rocketman221projects]

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.

[@jrevillug]

Yay, nixie tubes. You keep making me wince when you're playing with 170V with both hands on the work though. I know it's a current limited supply, but anything above 48-50V and I like to keep one hand in my back pocket at all times, just good practice.

[@Tomasu82]

i really enjoy your project and tutorial videos Dave! keep up the good work :)

[@DoRC]

I know it would be massively impractical but it would be cool to have each digit powered by a physical relay. Hearing all this relays clicking and clacking would go well with the old school feeling

[@jtsiomb]

Search for a video called "Mechanical Nixie tube Clock!!"

[@DoRC]

John Tsiombikas now that's what I'm talking about! The noises are a perfect match for the tubes!

[@TheDefpom]

Wouldn't you be able to use series diodes to act as blocking diodes for reverse bias to prevent reverse voltage passing into the device?

[@cheetahkid]

the totem pole can be useful if you put a 48v on the HV input of the ic rather than 200v. there is a reverse protection built in to the totem pole if you look closer, I know it will work with lower voltage if some of the ic's has a lower voltage totem pole... test that out. nixie still at 170v via resistor. and the off state because of 48v zener will hold out max 50v, different ic's may varies, one I seen 60v and 80v.

[@antipoti]

Yes they do sell those nixie driver chips 4bit binary to 10 digit output high voltage low side driver. I managed to buy about 50 of them from Poland I think. You wouldn't buy them in a regular store, but it is very possible to get your hands on them. Using hv shift registers is a very clever idea though. My first attempt was to use transistors and multiplexing, but it had an annoying shadow effect, so I bought those drivers. They work perfectly.

[@TheBrandon164]

Pure Nixie action!

[@bertoid]

I have 6 of these tubes, so I'm interested in this project. I like a single chip solution for minimum parts, but separate SR-latch and driver chips only doubles the part count, so not too bad. And it means jelly-beans can be used, so this zener trick is a great idea. I guess a single zener would be enough for ALL the tubes (would only dissipate about 100mW for 6 tubes), but I'd be using one per ULN2003. Just seems safer...

[@rikvdmark]

Great video Dave. Learned something new! I love Nixie Tubes :) Recently ordered a kit from Elektor to make a Nixie Tube clock Arduino shield :)

[@theIpatix]

What happens if you just disconnect the HV from the totem pole supply voltage? Will it become an open drain/collector output or is there something that I don't understand right?

[@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

[@DrB1900]

That switchable resistor box is really nice, but man those things are expensive.

[@power-max]

What if you used an HV diode to allow a totem pole to effectively only sink current? The only disadvantage would be a lot of diodes...

[@ragnor0k]

The very low cathode current that results as a result of clamping the output with the 48v zener is often talked about being linked to a "poisoning of the cathodes" exacerbating reduction of light output over time.... I'm not too knowledgeable on the chemistry of the Nixie tubes, but a similar thing does certainly occur within fluorescent lamp cathodes, (a separate issue to the well known poor preheating). Ive mainly designed clocks that are displaying 24/7, so have always erred on the side of caution.

[@FarleyHillBilly]

With 200v on the anode and 50v on the digit, theres only 150v across the tube, the striking voltage is 170v, so the digit stays off.

[@WilmerAriza]

These projects are great, keep on, not like the power source.

[@krisztianszirtes5414]

16:22 Jattaseat

[@ExpiredCartonOfEggNogg]

Make a nixie tube calculator !

[@ChipGuy]

For the wrist ;)

[@TheOriginalEviltech]

With a single nixie!

[@almondjake1]

Gotta finish the uCalc first.

[@ikastolero]

I have a nixie calculator lol, but is a rare micro 7 segments nixie display. It isn't so pretty.

[@JoelGarcia-ml9jx]

Those HRC fuses look like their kept handy Dave....... :-)

[@hyperplastic]

Great video!

[@ElectronicsDemon]

eagerly waiting for nixie clock.....

[@christiandinkel8481]

Electronics Demon is it really going to be a clock? Why the 8 digits?

[@OneBiOzZ]

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

[@EEVblog]

Maybe possible, would have to try it.

[@pratherat]

I came here to say the same thing, or better, tie it to ground.

[@Gameboygenius]

+pratherat Ground it, absolutely not. This will short every segment to ground, either becayse the transistor is closed, or due to the body diode of the P channel FET. Realistically possible options include: leave it unoconnected, high value (100k?) resistor to HV+, zener diode to ground, or combination of the two, ie a resistor-zener divider to generate a known although high impedance voltage.

[@pratherat]

+Gameboygenius Oops. Forgot about that. Thanks!

[@seifeldinhashem9634]

I love these videos btw, they're so fun and educational, I need me more videos that explain to me the electronics engineering process and how to use digikey

[@aklef]

Ooh, links to those thumb-actuated clamping probes Dave uses?

[@TheChipburner]

Dave, You may use MMBTA42LT1G instead of all that drivers

[@odczynnik]

Use 74141 driver:-) it's 4 bit driver for nixie tube. I have those to my nixie project, but haven't time to done it:( My idea was use arduino with PCF8574 expanders (I2C), and one expander can control two, 74141 drivers. You can control nixie display by only 2 wires.

[@Seegalgalguntijak]

I'm quite the electronics beginner. However, I've recently bought a UA723CN 5V voltage regulator in a 14-pin DIP package to replace a component made in 1980, and I was really surprised how easy this was to obtain, for just around 60 cents or so. Is it normal that a chip that was invented in the 70s is still available today?

[@God-CDXX]

use BA12003B this poppy is rated 60 volts I have the same nixie tubes these worked perfect I built a clock my ZENER is 55volt my dropper is 27 k 1/2 watt carbon film I am running 175volts on the HV I put a 750 k 1 watt carbon film from ZENER to 175 HV supply

[@radarmusen]

Maybe I overlook something, but would it not be better to have resistors on each digits. That would help if two digits should short in example ULN2xxx.

[@filipeterra8981]

dave, try pc817 as anode driver. Practical Vceo is a lot higher than the rated 80V.

[@kuhrd]

Why not simply use a multipack resistor to simply pull all the nixie tube pins, including the one being driven, to ground? As long as the value is high enough that it will not negatively impact the driver transistor when it is on I would think that would be a lower tech solution and all the pins would not be floating at any voltage.

[@anatolijne]

You could use a cheap Servo Motor for each tube with Multi-pole Switches :D

[@TheKeyote]

Aww, I was rooting for the "Microchip solution"

[@thejulianmachine]

on my nixies i use MPS A42 as high voltage transistors =)

[@sunebrian1423]

Hi Dave, could you explain the measurement of the leakage current @11:48 if you are meauring the current between the 22k resistor and the anode of the tube. It seems the total current doesnt add up logically? If the leakage current are passing through the 22k resistor to those open pin via a zener diode, the expected current should arround 1.59+0.33 ~ 1.92mA?

[@PeterCCamilleri]

or... you could use a dedicated 22 k resistor for each totem pole driver chip.

[@muddbogginredneck]

been subscribed to you for a while. i love how you explain things, and show how they work if people ask, tho i do think you can be a bit snobbish ( ish that even a word? ) but thats just my opinion, keep up what youre doing mate, and thank you for all the content.

[@DAVIDGREGORYKERR]

the one I suggested are for 250v ce

[@abdullahseba4375]

what happened to David 2?

[@MrVoltz]

What if you leave the HV input of the totem pole drivers disconnected? Will they behave like open-collector?

[@John_Ridley]

That was my thought too.

[@sunebrian1423]

Hi Dave, would you need several 6 nixie driver pcbs ? I can send you different tube version with schmeatic and layout (free)? My design is similar to your design with build in high voltage step up 12V -> 170-180V.

[@ebiscaia]

Dave, What about playing with audio tubes?

[@TheOriginalEviltech]

Dave the ULN2003 will not work if you do that. You'd probably fry any other connected logic aswell. The COM pin needs to be referenced to logic GND for the ULN2003's inputs to function. However you can make voltage dividers on all of the pins to pull the voltage within reasonable levels and than adjust the voltage source so a 40V difference on the Nixie tube's pins would toggle it between on and off state. Yes, that's allot of resistors, but it's cheaper than an expensive 32bit high voltage shift register... I found a pair of 32 bit VFD display drivers but they are only 30V capable.... I might just go with discrete transistor solution with the MMBTA42... Way cheaper than the others.

[@EEVblog]

How exactly can you damage the inputs? they have input protection resistors internal. Sorry, I don't see it.

[@TheOriginalEviltech]

Sorry, i was wrong. Thought the com was the ground pin. :) Love your videos by the way, i was just planning to make a nixie display out of old spare parts for my old CRX's spedometer :)

[@EEVblog]

Phew!

[@ChipGuy]

You sad that the ULN2003 is one driver short. What about the ULN2803 with 8 drivers, that would include the decimal point?

[@EEVblog]

Err, it's a Nixie tube, not a 7 segment display, it has 10 digits.

[@ChipGuy]

Oops... yes of course, how could I miss that... I 'm so used to 7 segments these days... Doh, won't make a big difference then. 10 or 12 ICs, hmm.

[@EEVblog]

I think I said segments like 3 times in this video!

[@ChipGuy]

Fair enough

[@DreitTheDarkDragon]

What about diode in series with push-pull output?

[@untitled8027]

had no idea you had 2 channels honestly

[@hene193]

00:12 OMG Dave is working on The Final Solution! :o I know... A really bad joke...

[@hene193]

InXLsisDeo Yea but it wouldn't have referred to Nazies... Most likely that would have been better.

[@WereReallyRelayCamping]

at around the 16:00 mark, the hv pin, just leave it disconnected?!? it seems so obvious i'm shouting at the screen lol, so if its so obvious, what am i missing ?

[@babylonfive]

I did the same thing. Unless the HV gets used for some internal bias? That shouldn't even matter...

[@power-max]

I think it may matter considering the HV pin is common to ALL the outputs in a single chip.

[@primate3609]

Niceee you should explain and take apart those asus STRIX 7.1 headphones and their multi channel amp !!!

[@robh1908]

What's going on? Carlson's Lab started this a few months ago and now every electronics guru is jumping on the wagon.

[@Brainstorm4300]

Sorry, I'm just a novice hobbyist. If you clamp the voltage with a 48V zener then the transistor inside the driver will only have to withstand 120 (for example) - 48 = 72V. So the maximum open collector voltage can be as low as 72V, right? Please correct me if I've got it wrong.

[@EEVblog]

No, the transistor only has to cope with the zener voltage. The anode resistor and the nixie tube drop the rest of the voltage.

[@failureisfunny3211]

Isn't 48V zener too much "tight"? Counting tolerance, the diode drop, and the zener dynamic resistance, the collector could reach a voltage above 50V...

[@Brainstorm4300]

EEVblog Another question! Shorting all the pins yields about 125v but didn't understand why you said "you guessed it". Is there a way to know that without measuring?

[@kapytanhook]

The highest voltage or lowest voltage drop was already measured. When tied together you expect the lowest voltage drop to count for the bunch.

[@RobynTapps]

lol nice custom meter Dave lol

[@zodak9999b]

I like the ULN2803, since it has 8 transistors

[@EEVblog]

You'd still be two short

[@zodak9999b]

But for an 8 digit display (with decimal) you could use 11 chips and have no transistors left over. With the 2003 you're using 13 and have 4 transistors spare.

[@zodak9999b]

Duh 3 spare

[@nikolaipavlov544]

One can just use K155id1 (Soviet clone of 74141 but with 2.5mm not 2.54mm pin pitch ) to drive Nixies..

[@mosfet500]

Hi Dave, Where did you get those nice test probes?

[@God-CDXX]

i recommend you not run below 170 volts on the main plate supply the tubes gane voltage drop over time that is why i used 175 volts you will thank me for the 170 - 175 volt choice

[@Teth47]

0:10 What is this "Final Solution", Dave?

[@xFuaZe]

Why doesn't the Playlist include part 1?

[@km5405]

I like jellybeans, they are sweet and don't cost much

[@thebossofbox]

Dave CAD FTW

[@TheManLab7]

I sort of knew what you meant and I know as you said (they are as cheap a chip/ten a penny) but why do people say or call the components jelly bean?

[@andycristea]

TheManLab7 Because jelly beans are a common type of candy available almost everywhere and from many brands...

[@TheManLab7]

Andy Cristea ahhhhhhh. I get it. Cheers boss!

[@malcolmholmes115]

Hey Dave, is it possible to order your multimeter to Bali?

[@ArkanoidZero]

Hey Dave, looks like you put the update for the laptop on this video accidentally, thought I'd let you know! :3

[@EEVblog]

Oops!

[@78trav]

ArkanoidZero what time? I missed it.

[@ArkanoidZero]

travis shrewsbury it was just some text in the description, nothing in the video itself

[@AverageJoe2020]

Why not a diode in each digit line?

[@danijel124]

I just have one question. Where do you find time to do all this stuff plus going to work an caring for your family???

[@EEVblog]

This *is* my work.

[@debug_duck]

This is his work...

[@choknuti]

You can make a decent amount of money on youtube. Especially if your content is a s good as Dave's.

[@KennethScharf]

wouldn't the zener clamping diodes cause 'ghosting' on the unlit digits?

[@JulieBrandon-geekycow]

The current through all of the off digits (nearly said segments then) in total was only something like 100uA, wasn't it, or like 10uA each?

[@WilmerAriza]

here we go....

[@shakaibsafvi97]

good man Dave ! let me know if you like some help with the layout. I'd love to work under your supervision... :)

[@christiandinkel8481]

...

[@shakaibsafvi97]

LOL.... was my comment that transparent?

[@christiandinkel8481]

...

[@shakaibsafvi97]

therealnightwriter you have a particular interest.... hope you're not one....

[@christiandinkel8481]

...

[@DAVIDGREGORYKERR]

Could you not use BUV21 metal cased power transistors to switch the voltage has collector emitter of 250v.

[@EEVblog]

There are countless transistor that could be used.

[@magnehaneberg8605]

I got some MMBTA42's in SOT23 for my Nixie project years ago. They work nice, too.

[@Renegade30]

I hate it when people use the term final solution... Just makes me cringe... Thanks for the interesting video though!

[@TheRealThisIsAlex]

Awesome.Nice Dave.What is his PO Box Address? I want to send him some stuff.

[@PlexusAU]

Go on his channel page then click about...

[@TheRealThisIsAlex]

TheAnnihilator tenksz

[@SuperLastTrain]

Is it easier to drive a nixie tube than a vfd?

[@SuperLastTrain]

BlinkY tried to drive a vfd a couple of years ago and I failed. Using original driver ic, multiplexer, power supply and an arduino nano

[@FıratDeveci]

Just use 200V transistor and simple 595 chip. Everybody in the world can find easyly on market these things. Why are you thinking so much about that, i can't understand, it's obvious to know not trust the voltage drop on nixies.

[@donpalmera]

A two second simple solution doesn't generate youtube bucks.

[@EEVblog]

Because it's (I think) interesting content, and I explained that driver chips are less hassle to solder than 88 transistors.

[@EEVblog]

+donpalmera It's not about the bucks, it's about learning and creating content for an *electronics engineering* channel. There is a lot of value in going through all sorts of design decisions. If they seem obvious to you, they may not be obvious to a beginner.

[@donpalmera]

EEVblog Yeah I get that. The point I was making was that *start video* Gonna drive some nixie tubs, gonna use some transistors, come back next week for 10s of something else *end video* isn't really valuable to anyone.

[@FıratDeveci]

Dave you think very elegant, I think you missed some points; we can get different ICs from anywhere but think about beginners, like 10-16 years old hobbiest, they can't use credit card or ext. They can't get these special(!) ICs very easy; you know that. Why I said 595 and 200V transistor, everybody can find them very very easy in very low prices. Maybe 88 transistor soldering is hard but you can get 100 transistor around like 2-5 bucks! Any children can build clock or ext. with nixies, without eating lollipop. And please think; what will you do when your special(!) IC burns when you are soldering it? It hurts. But if you burn 2-3 transistor while soldering, it won't! I'm very curious about what you are gonna use at this projects. This is my bet; you will found Supertex ICs from Microchip.

[@EngineeringNS]

you say "jellybean" a lot recently--What does that mean?

[@EngineeringNS]

oh, you answered in the video

[@mattibboss]

jelly bean!

[@__dm__]

yo

[@muhammadchaudhary2666]

3rd

[@vincenthamilton4792]

7th