Nixie tube clock... without the nixie tubes!

[cprobertson1]

Well let's face it folks - Nixie tubes are cool.

They're also not convenient to use... you need a relatively high, or actually high voltage, and they're fragile, and they don't last all that long... and they're also expensive.

So... this leaves me with a problem: how can I make a realistic looking alternative?

I've got two ideas on how to do it:

1) Thin edgelit acrylic with holes drilled or lines etched in it: and a 3D printed grid on the top for that retro look: 11 separate <1mm acrylic sheets (one for each digit + decimal if required) - each individually lit by a 1005 or 1608 LED or two at the bottom - light one as you want it.

2) SMD matrix on a DIY etched board. One line of LEDs per digit: would be a nightmare to etch a double sided board which would perforce be pretty complex for 11 digits sitting on top of each other (though I could be sneaky of course and make what'd effectively be a glorified 7-segment display by re-using segments of the digits)

Both these ideas would then be mounted inside glass tubes, which I might even go so far as to have custom made ( have a friend who does glass blowing: I think he'd relish the challenge!). In effect, we're making a fake Nixie tube.

What do you folks think? I think both ideas would work but'd be quite a bit of work (though the acrylic idea can probably be sped up by etching/drilling with a CNC mill (I work as an tooling engineer so I can probably borrow one of the machines at one point)

Can anybody think of any other ideas or improvements?

Ps - I know I **could** fork out and just buy some nixie tubes, but making my own sounds like so much more fun! I'll post more on the project as it develops

[BlueBill]

What you described will look like an LED display. Nothing comes to mind that'll look like a glowing wire in a vacuum.

[Richard Crowley]

If you are talking about fully-formed, curvaceous numerals, dunno what you could substitute.
But if you are talking about segmented (7-segment or 15-segment "British flag") displays,
there are those "LED filament" pieces that they are now using to make retro-looking mains lamps.



I suspect you can't bend those things without breaking or otherwise ruining them.
But I don't know for sure.  I have never seen one to play with it yet.

http://www.aliexpress.com/store/product/LED-filament-chip-1W-for-bulb-light-13mA-74-8v-112LM-W-warm-cool-white-Light/528280_1862140831.html

[nctnico]

I'd use a TFT screen.

[calzap]

There's also the 3-D and reflective aspects of nixie aura that would be hard to duplicate.   These are especially noticeable up close. 

Mike in California

[sleemanj]

http://softsolder.com/2013/09/11/edge-lit-acrylic-nixie-display-doodles/
http://hackaday.com/2013/05/17/led-retrofit-for-vintage-edge-lit-numeric-display-modules/
http://hackaday.com/2012/02/18/edge-lit-nixie-tube-is-sheer-brilliance/

[CatalinaWOW]

With your access to a glass blowing friend you could make your own "real" nixies.  Or if high voltages are a real problem, look into making your own "vacuum fluorescent" displays in a nixie configuration.  Those were used in automotive applications in the 70s, using 12V mains.  I don't believe they stepped the voltage up much, if any.  Or as a final thought, the science experiment/surplus market has trimmable electro-luminescent sheets that could be cut into numerals and packaged in a tube.  This option would have stacking problems since the lumens per unit area would force you to make the numbers "thick"".

[codeboy2k]

fake it with an LCD screen and images of nixies, like this android app below...



https://play.google.com/store/apps/details?id=com.smartphone_zine.divergenceclock

[kwass]

If you are talking about fully-formed, curvaceous numerals, dunno what you could substitute.
But if you are talking about segmented (7-segment or 15-segment "British flag") displays,
there are those "LED filament" pieces that they are now using to make retro-looking mains lamps.



I suspect you can't bend those things without breaking or otherwise ruining them.
But I don't know for sure.  I have never seen one to play with it yet.

http://www.aliexpress.com/store/product/LED-filament-chip-1W-for-bulb-light-13mA-74-8v-112LM-W-warm-cool-white-Light/528280_1862140831.html

I've played with these some.  They bend very easily and hold their shape once bent.  They contain many (28 in the ones I have) tiny LED's in series and so require a high voltage.  They also are much brighter than a Nixie tube filament even when run at just 1 mA.  I think that they could be used to make a nice numeric display that would last a very long time and not be too fragile.  But you'd still need the high voltage.

[cprobertson1]

Foah! Lot's of replies xD

@Kwass + Richard Crowley - That looks promising if they can be bent What sort of voltage are we talking about here? The ones I saw ran at around 50-60V at 15mA which I can probably drive with some BD139 or some mosfets if it comes to it (I'll figure out the details later ) I've actually just ordered some to play around with xD Any idea how far they can be bent before they break?

As a side thought, it may actually be possible to make my own if I'm careful about the substrate I use to mount them on, and then coat them in a coloured resin (or better yet, it may be possible (though we're now branching into the experimental side of things, as I can't see much on the web about this idea) - to use some UV leds to trigger fluorescence in a chemical embedded in a transluscent polymer from within (i.e uv light inside, fluorescent material on the outside - brightness would be a problem though!))

Anyway, that last idea is definitely for a future project (my degree is in biochemistry despite working as an engineer (and having an EE hobby xD) - so getting hold of such a polymer wouldn't actually be too difficult nor costly. If I ever try it I'll be sure to post back, could actually get some interesting effects if it works.

@codeboy2k - Nah, that's no fun! Would be surprisingly easy to do though I want that retro feel: and I'm totally not making a replica time divergence meter from the Steins Gate anime to use as a mantelpiece in my new flat... honest! Plus, as I said, Nixie tubes look cool - if I were to fake it (which I think I'm going to do) I'd want at least a similar form factor

@nctnico - That's not a bad idea! As calzap said it wouldn't be perfect as there'd be reflective/aural differences between a real nixie tube, but mini TFTs mounted inside glass tubes is definitely on the drawing board!

@sleemanj - Nice links - I saw something similar to that numeric display - my plan was to get in there with a V-Groove bit - but there's a catch. I'm going to etch it on both sides, and paint one etching black: so that it reflects when there's light but looks like a wire when there's not. We'll see how it turns out, Need to wait for the acrylic to arrive before I can test it (managed to grab an A4 sheet for £1 at 1mm thickness).

@calzap - Aye, I know =/ I figured if I can get something that looks good at even minor distances, it'd be the next best thing to real nixie tubes - even if they're not that realistic. It's a trade-off I'm afraid If I go with the LED filament idea, then the voltage wouldn't be too far off that of nixie tubes and I make make an optional bracket for replacing my fake tubes with real ones. We'll need to see how much engineering I can be bothered pouring into it first!

@CatalinaWOW - I think my friend would demand a fortune for the time required to embed all the wires through it It's not impossible though - but he does have his limits to what he considers a "favour" and what he considers to be "actual work" It is VERY tempting to make an actual nixie tube though... wonder if I could get him to teach me glassblowing...

The Vacuum Fluorescent idea is also an option, though either way I'd need to figure out a way to evacuate the tubes and/or substitute the gas for neon.

Actually both those ideas sounds kinda dangerous - never trust me with hot things No seriously, I have a resistor shaped scar on my finger after I ended up with a tiny solder bridge shorting onto it :S

[mikeselectricstuff]

The reason nixies work is that the glow is significantly thicker than the electrode, so electrodes in front of the lit one don't completely obscure it. There isn't really any way to replicate this effect, which is why nobody has succeded in emulating it. 
I don't know why you think they don't last long - decent ones can have 10-20 years running 24/7. Once mounted they're not particularly fragile either.

Nothing beats the glow of ionised gas!

[cprobertson1]

@mikeselectricstuff - ah, see the last one I played with lasted a year - and I had based estimates on that; some folks on the interweb have said they've had tubes last 30-40 years.

Aye, emulating it 100% won't be possible unless somebody invents something awesome sometime soon: but oh well, I'd settle for a 50% emulation

Nothing beats the glow of ionised gas!

I second that!

As I said, I'll probably make an adaptable bracket that can take a either my fake ones or a proper nixie tube (i.e a 3D printed mounting bracket you can swap out with a real tube whenever you want: with a couple of internal adjustments. Again, really depends on how much time and money I want to sink into the project!

[VK5RC]

Save up the cash, get the real thing and a few matching spares, I have had a few go dud on me early (after a year or so).
You will really enjoy looking at it. GPS lock it if you can get a signal where the clock will go.

[codeboy2k]

If you try to buy them individually off ebay or some surplus store, you'll pay like they were gold ...

I find it's much better to visit a surplus guy in your neighborhood and let him know you're interested in anything with nixies... when he gets something he's happy to sell you an old unit with a 6 nixies in it for 20$

[c4757p]

@mikeselectricstuff - ah, see the last one I played with lasted a year - and I had based estimates on that; some folks on the interweb have said they've had tubes last 30-40 years.

Did you mux them? A lot of "nixie clock" designs floating around do that, and it abuses the hell out of the cathodes. Drive them direct.

[Kalvin]

How about bending a thin PVC optical light guide into proper numerical shape and lit it with LEDs from both ends? Similar to the angel eyes.

[tiltit]

Did you mux them? A lot of "nixie clock" designs floating around do that, and it abuses the hell out of the cathodes. Drive them direct.

It may also depend on the type of nixie tube. I believe I remember reading something about the presence of mercury in the later ones making them a lot more durable. Anyways, I have built a couple of clocks that use the IN-12B that are multiplexed and they have been running happily for about a year now and no sign of dimming what so ever.

The IN-12 is also quite cheap on ebay. The IN-2 are also cheap and rather pretty, but I have read that they are not as durable.

[cprobertson1]

Did you mux them?

@c4757p - I donkt *think* I did -  I had followed some random tutorial online for setting them up (this was before I knew what I do now about electronics). It might just have been a dicky tube I got as well; it may even have been second hand! I wouldn't put it past some dumb error on my part as well (as I said, I was just playing around with one before I had any real EE experience: though I think I was sensible enough to follow the guidelines? I'll put it down to either a defective tube or user stupidity )

Just out of curiosity (I'll obviously look this up before I do anything!) What is the correct way to drive them?

I haven't really looked into it yet - was going to try out the fake-nixie ideas first (which could be as simple as an AVR or PIC driving a bunch of transistors which let a current through the required digit whenever you need it lit: take it if I were to do it with a lot of nixies (say, eight, for example where I to do date (DD/MM) + 24H time)) - would it be possible to choose which electrode to power on the nixie using a shift register (so to avoid it "flickering" through the whole 8 bits of the SIPO as I put the data in, I'd have a second mosfet on the common anode/cathode of the nixie to break the circuit) - or would that cause the same problem? (mind the fastest changing nixie would be the minute counter)

As I said, I haven't thought this through yet, just firing ideas onto the table - in fact I'm going to look at designs for driving them just now

NB - probably going to go with AVR ATTiny or ATMega for the brains of the operation, because I have a pack of them lying around Might be overkill for a simple clock, but nvm


@codeboy2k - I'm afraid we don't really have a surplus of surplus stores () in the UK - even fewer in Scotland! A quick and by no means comprehensive glance suggests the nearest one might be a good distance away =/ Mores the pity!

@Kalvin - another good idea! I wonder if I can use my transluscent PLA filament from my 3D printer for it actually... might try that tonight - will need to heat treat it for the flexibility and transparency, but still that won't be too hard. I'll see what I can do!

I'll summarise my intentions tomorrow on all the various fake-ideas and outline some pros and cons (and hopefully when I plan to get test pics up!) Ah! It's good to be working again!

[cprobertson1]

The IN-12 is also quite cheap on ebay

Ah! Should have said earlier - looking for the vertical nixie tubes, a bit like this:



I think ebay might be the place to go, there are a couple of folks selling them in bulk: 24 should last me a lifetime

[tiltit]

There is a nice little chip you can use to drive the nixie kathodes. Namely the HV5812 shift register. It is meant for VFD tubes but it will also works with nixies.

[cprobertson1]

There is a nice little chip you can use to drive the nixie kathodes. Namely the HV5812 shift register. It is meant for VFD tubes but it will also works with nixies.

Nice! This is looking better and better

[mikeselectricstuff]

TI's TPIC6B595 has a clamp voltage of 50V, which should be OK if your HT is reasonably regulated. It's a while since I did anything with nixies - I don't recall offhand what the typical strike to extinguish voltage window is.

[kwass]

@Kwass + Richard Crowley - That looks promising if they can be bent What sort of voltage are we talking about here? The ones I saw ran at around 50-60V at 15mA which I can probably drive with some BD139 or some mosfets if it comes to it (I'll figure out the details later ) I've actually just ordered some to play around with xD Any idea how far they can be bent before they break?

I need about 70 volts for the ones I bought.  They can be bent very tightly -- just a few mm bend radius without breaking.

[linux-works]

nothing beats real nixies.  don't try to simulate it, just buy the tubes and build your own clock.  not hard.  here's mine:



pic of the main protoboard for my own DIY nixie clock:



I did no work on the psu; just bought a module from fleabay and it works great:

http://www.ebay.com/itm/140964710736

$15 each - hard to complain about that.  I give mine 5v from usb power and it works super!  mine is almost a year old, now, and still chugging along.

I don't mux mine, I don't even run the cathode poisoning logic on them, I just drive them direct and without complication.

I grew up in a house that had a diy nixie clock (a relative built one when I was a kid) and I remember that clock running for way more than 10 years.  I bet it was closer to 20 years but I know it had a good solid 10 years of 'always on' life to it.

for my build, I used a gps module and arduino nano as well as a battery backed i2c rtc module.  the rtc holds the time while gps gathers data, then its gps driven after that.

was a hell of a lot of work to hand solder it all up:



and some day I do plan to make a pcb for it.  (had to be sure about my design before I spend time on a pcb, so pt-pt wiring is almost always the first version of anything I build.)

[Richard Crowley]

nothing beats real nixies.  don't try to simulate it, just buy the tubes and build your own clock.  not hard.  here's mine:

Brilliant!  Great job, linux-works!