Nixie tube clock... without the nixie tubes! - Page 1
Forum section: electronics / projects

author: cprobertson1
author_rank: Frequent Contributor
timestamp: February 27, 2015, 09:31:39 pm
content: 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 canprobablyborrow 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

author: BlueBill
author_rank: Regular Contributor
timestamp: February 27, 2015, 09:55:31 pm
content: What you described will look like an LED display. Nothing comes to mind that'll look like a glowing wire in a vacuum.

author: Richard Crowley
author_rank: Super Contributor
timestamp: February 27, 2015, 10:04:12 pm
content: 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

author: nctnico
author_rank: Super Contributor
timestamp: February 27, 2015, 10:19:52 pm
content: I'd use a TFT screen.

author: calzap
author_rank: Frequent Contributor
timestamp: February 27, 2015, 10:30:24 pm
content: 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

author: sleemanj
author_rank: Super Contributor
timestamp: February 27, 2015, 10:38:07 pm
content: 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/

author: CatalinaWOW
author_rank: Super Contributor
timestamp: February 28, 2015, 05:00:52 am
content: 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"".

author: codeboy2k
author_rank: Super Contributor
timestamp: February 28, 2015, 05:24:21 am
content: 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

author: kwass
author_rank: Frequent Contributor
timestamp: February 28, 2015, 07:57:47 am
content: Quote from: Richard Crowley on February 27, 2015, 10:04:12 pmI'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.

author: cprobertson1
author_rank: Frequent Contributor
timestamp: February 28, 2015, 09:31:56 am
content: Foah! Lot's of replies xD@Kwass + Richard Crowley - That looks promising if they can be bentWhat 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 thoughI 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 afraidIf 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 itIt'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 thingsNo seriously, I have a resistor shaped scar on my finger after I ended up with a tiny solder bridge shorting onto it :S

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: February 28, 2015, 10:03:22 am
content: 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!

author: cprobertson1
author_rank: Frequent Contributor
timestamp: February 28, 2015, 10:44:31 am
content: @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% emulationQuoteI 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!

author: VK5RC
author_rank: Unknown
timestamp: February 28, 2015, 11:48:18 am
content: 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.

author: codeboy2k
author_rank: Super Contributor
timestamp: February 28, 2015, 08:22:03 pm
content: 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$

author: c4757p
author_rank: Super Contributor
timestamp: February 28, 2015, 08:38:34 pm
content: Quote from: cprobertson1 on February 28, 2015, 10:44:31 amDid 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.

author: Kalvin
author_rank: Super Contributor
timestamp: February 28, 2015, 08:47:25 pm
content: 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.

author: tiltit
author_rank: Regular Contributor
timestamp: February 28, 2015, 08:52:23 pm
content: QuoteIt 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.

author: cprobertson1
author_rank: Frequent Contributor
timestamp: February 28, 2015, 09:17:11 pm
content: Quote@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!) Whatisthe 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 nowNB - probably going to go with AVR ATTiny or ATMega for the brains of the operation, because I have a pack of them lying aroundMight 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!

author: cprobertson1
author_rank: Frequent Contributor
timestamp: February 28, 2015, 09:20:08 pm
content: QuoteAh! 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

author: tiltit
author_rank: Regular Contributor
timestamp: February 28, 2015, 10:06:13 pm
content: 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.

author: cprobertson1
author_rank: Frequent Contributor
timestamp: February 28, 2015, 10:47:52 pm
content: Quote from: tiltit on February 28, 2015, 10:06:13 pmNice! This is looking better and better

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: March 01, 2015, 12:24:38 am
content: 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.

author: kwass
author_rank: Frequent Contributor
timestamp: March 01, 2015, 07:23:56 am
content: Quote from: cprobertson1 on February 28, 2015, 09:31:56 amI need about 70 volts for the ones I bought. They can be bent very tightly -- just a few mm bend radius without breaking.

author: linux-works
author_rank: Super Contributor
timestamp: March 01, 2015, 04:33:47 pm
content: 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.)

author: Richard Crowley
author_rank: Super Contributor
timestamp: March 01, 2015, 04:52:13 pm
content: Quote from: linux-works on March 01, 2015, 04:33:47 pmBrilliant! Great job, linux-works!

author: linux-works
author_rank: Super Contributor
timestamp: March 01, 2015, 06:39:30 pm
content: <soapbox>btw, the reason I had to mount that dc/dc upverter upside-down is that the designer of that module did not -care- about being .1 hole space standard. sigh. I emailed him, told him how inconvenient it was to deal with his module that way and his attitude was 'just design your own green board and use my pin spacing for when you mount my module'.sigh. he just does not get it.folks, if you -can- follow the .1" hole spacing standard when designing DIY modules for sale, please do. some of us still do appreciate being able to perf-board a proto or one-off build, and if you are not .1 compliant it causes us much grief.</soapbox>

author: cprobertson1
author_rank: Frequent Contributor
timestamp: March 01, 2015, 06:43:42 pm
content: QuoteNice work! I approveAye, the problem is the initial cost of the nixie tubes (I'll probably end up forking out on them the next time I see a decent deal for a bunch of them online: need to wait until I can afford some throwaway cash first though xD

author: c4757p
author_rank: Super Contributor
timestamp: March 01, 2015, 06:48:01 pm
content: Nixies occasionally go for quite cheap. I've got rather a bunch of them that I was planning to use - never got around to it - and paid a few bucks for them all IIRC. Be patient, and don't insist on having one of the two or three extra-popular parts.

author: kwass
author_rank: Frequent Contributor
timestamp: March 02, 2015, 02:52:57 am
content: Quote from: linux-works on March 01, 2015, 04:33:47 pmYou can buy directly from Taylor and they sell a vertical mount 0.1" pin spaced version:http://www.tayloredge.com/storefront/SmartNixie/PSU/index.htmlI've used this in a couple of my Nixie clocks with good results.

author: linux-works
author_rank: Super Contributor
timestamp: March 02, 2015, 02:59:38 am
content: I did buy a taylor dc/dc, as well. yes, there are vertical mount ones. I liked the stability of the horiz one, though. just wish he could have moved a few pins over a bitthere are in14 and in16 tubes that are the size I used. I used the ones that have the proper 5 numeral. I think that's the in16. around $60 for a set of 6 from russia or ukraine (for some reason, most are from ukraine). shipping is about a month ;(lots still around. I don't know how long the supplies will last. wonder if anyone has any idea at all how many are left in the various seller's hands. do we have years of hobby clock building still left? what if someone snarfs up most of the market? they are not being made anymore, that's for sure.also, on the really large tubes, I've heard about a blue glow that you want to avoid; and that often means using US 74141 chips instead of the russian versions. and those chips are long gone from the parts channels; even used its hard to find the US chips. and the large (nice!) tubes are hundreds of dollars for a set of 6. but you can still buy them and I've seen at least 10 sellers on ebay with them for sale.

author: macboy
author_rank: Super Contributor
timestamp: March 02, 2015, 03:25:19 pm
content: Quote from: CatalinaWOW on February 28, 2015, 05:00:52 amVFDs in the 70's!? Yes. Today? Yes. My 2009 Subaru has beautiful white-on-black VFDs for its audio system and clock/trip-computer displays. In the dash, the odometer is a cheap looking black-on-grey LCD. What a shame. VFD may be an older display technology, but it is still relatively widely used, especially in harsh environments like cars. VFD's can be lit with as little as 12 V on the grid and anodes, depending on construction, but 20 V - 40 V or higher is more common.

author: nickds1
author_rank: Contributor
timestamp: March 02, 2015, 04:57:01 pm
content: Quote from: c4757p on February 28, 2015, 08:38:34 pmAbsolutely not so - many of the 100s of different types of nixies were explicitly designed for muxing - Burroughs, National and others detail the methods in their technical documentation - it's not complicated.Also, most nixies have a small amount of mercury in them to limit cathode poisoning and sputter. Most such nixies have a designed lifespan in the order of 200,000 hours, or nearly 23 years of continuous running.There are reasons why a nixie may not last that long - it may be old, it might not have Hg in it, it might be damaged, or, most importantly, you may be over-driving it - overdriving causes an exponential shorting of a nixie's life.FWIW, "end of life" for a nixie is not well defined - Weston says that when 50% of the tube is sivered or a digit being poisoned , its time to call quits, as would cathode failure due to sputtering.Some people are making new nixies - its VERY complex , time consuming & expensive - have a look at Dalibor Farný's site athttp://dalibor.farny.cz/- its a tricky process - I, myself, have made neon letters and artwork - there are many many skills needed, none trivial, many dangerous, one certainly potentially lethal and all require extensive study & practiceAny questions about nixies, just askCheers,Nick (owner/moderator of the Google! NEONIXIE-L group athttps://groups.google.com/forum/#!forum/neonixie-l)

author: cprobertson1
author_rank: Frequent Contributor
timestamp: March 03, 2015, 06:20:50 pm
content: @nickds1: Useful advice! Aye, I was discussing with my glassblowing friend over the weekend, he can definitely make me an outer shell for one: and might even get away with putting wires through it - making it airtight and pressurising it with a particular gas mixture would be hard - and he's not sure how his glass would respond to heat (reckons we'll need to get a hard glass like borosilicate or specially treat it if there's going to be any real heat (otherwise it becomes weak and brittle - and depending on if it's been destressed may simply shatter - particularly under pressure)Looks like making my own might be out of my reach =/@linux-works I was thinking of making my own power supply (mostly because I want to try making one) - I'll have a good look around for chips, and if worst comes to worse I can probably hack something together.---Acrylic arrived today - will get pictures up later once I put a jig to hold it all together, but in my test it looked decent - though obviously no replacement for a nixie (still looks cool though)---Still waiting for LED filaments - I'm hoping these will show some promise!---Still waiting on a good deal for Nixie tubes. Theres a pack of 24 for £120 odds, +20 shipping from Ukraine - tempted but that's a lot of moneyPics coming soon once I get a jig together for testing

author: cprobertson1
author_rank: Frequent Contributor
timestamp: March 04, 2015, 01:27:06 pm
content: I just got a bonus at work. I've already spent it. 24x IN-14 Nixie tubes for £5 each - apparently new (from Ukraine! Wonder how muchthat'sgoing to cost me!)|Apparently theycanbe multiplexed - at least according to the datasheet. Not sure I will though, direct drive seems simpler- still looking around for ICs to drive them: I'm tempted (I think I said this already? Hmmm...) to use a shift register feeding through high voltage transistors and simply switching between which cathode to drive with the register (disconnecting the anode with another transistor to avoid it flickering through the other digits as the data is fed in.) - you know, I am almost certain I have said this before... because somebody suggested an IC for me... Here we are, "Tiltit" suggested the HV5812 shift register - I'll have a gander for that when I get home!Anyway - I'm aiming to make two clocks now (WHAT!?) one with nixie tubes and one with fake nixie tubes (this way I can practice making my own power supply with the fake-nixie solution) - and who knows, maybe I'll find a decent alternative on my journey- so I'll keep you updated on my designs as they progress!Going to give the acrylic-number another go tonight: got a new router burr to make the digits with - see if I can't get a jig together for holding them in place + stopping light going from one plate to the other. I'll need to use 5mm LEDs (to light 1mm acrylic plates... yeah) - so I'll only be able to light 3 or 4 of the plates individually but it will be enough to give us an idea if it's feasible. The final design will hopefully use 1005 or 1608 LEDs at the bottom (and maybe the top) - separated by an opaque "comb" (to stop the light from one acrylic sheet polluting the other). Going to mount this in a glass tube with an open bottom and drive each LED with a common cathode/anode. It will give more of a "floating sign" effect than I'd like, BUT, I have an interesting plan: mounting it inside some caging reminiscent of a real Nixie Tube (which will hopefully hide the corners of the acrylic, and the black or foil background will help with visibility)Its not a real substitute, but for cheapskates or people with too much time on their hands it may just be enough (Cost per Tube approx £3 - but you need to buy materials for more than 1 tube) to be worth the bother of making onePlus I don't think they'll look too bad. Should have pictures by the end of the week - maybe even tonight if it works (just depends on how much energy I have left after a day at work)

author: nickds1
author_rank: Contributor
timestamp: March 04, 2015, 02:16:25 pm
content: IN-14s are an "acquired taste" - the "5" digit is actually the same cut-out as the "2", but flipped and inverted - very odd - many people really dislike it. No idea why the Russians did this - we doubt that it would have saved much money, printing double the number of twos and no fives... personally, I never liked them and have never used them. Just checked my stock - out of the 7,500+ nixies I currently hold, only 9 are IN-14sThe IN-16 is slightly smaller and has the correct "5", like most nixies. I have over 1,200 of those at the moment...The problem with the Supertex drivers is getting hold of them - in the UK, the usual suspects (RS/Farnell/Rapid etc.) often don't have them, and sampling is not easy. Depending on the CPU you are using, you may need level shifters as well. Having said that, they are a good chip and widely used in many designs.Direct drive is simpler, but those Supertex chips aren't cheapThere are several latching shift-registers/drivers that will do which don't need extra HV cathode drivers, i.e. they handle that themselves. If you factor in the voltage drop across the nixie tube (typically around 120V), then you really only need an 80V-tolerant driver to be safe - 180-200V is completely unnecessary...

author: cprobertson1
author_rank: Frequent Contributor
timestamp: March 04, 2015, 07:44:38 pm
content: Hmmm - I could have sworn I replied while I was at work...@nickds1 - aye, Linuxworks mentioned that - according to the wikipedia, there are a few soviet designs that do it -apparentlyto reduce manufacturing costs. Meh, to be honest, looking at pictures online I personally don't it looks too bad - adds flavour if anything[I'll no doubt start a flamewar saying things like that!]Some pics of the sidelit acrylic - which actually didn't look too bad! Decent light (even in a lit room - though not the best of course!), good viewing angle, and it will look great once it's properly mounted inside a wire cage/glass tube designed to mimic a nixie (it actually looks alright on it's own as well xD)is it a nixie tube? no - but it is pretty easy to make - and though it has it's obvious shortcomings, when combined with a glass tube and some wires I think it may actually look pretty decent. Pictures were taken under different lighting conditions, and the photography is terrible - so I apologise in advance - gives some idea of what I can do with it though. These were 0.9mm thick with a 0.4mm etching on them (+/- 0.1mm because there's backlash in the jig I was using to cut them) and the number of plates doesnt affect visibility much (I tested using the three numbered plates + 8 blank plates which I couldn't be bothered etching)Anyway - catch you folks late! and thanks for all the help! With any luck I'll get an actual prototype made up before next week - depends on how busy I amDigit 2Digit 3Digit 1What the plates look like

author: linux-works
author_rank: Super Contributor
timestamp: March 04, 2015, 10:03:53 pm
content: if you want me to laser etch and cut some acrylic, as a test for you, I can do that. might be a bit easier and more accurate than cutting directly with a friction tool or router.(I tend to hang out at my local techshop at least once a week, anyway, so I could probably cut a few samples for you if you want, when I'm there next).

author: kwass
author_rank: Frequent Contributor
timestamp: March 04, 2015, 11:33:01 pm
content: Quote from: cprobertson1 on March 04, 2015, 01:27:06 pmI've built a few Nixie clocks and all are multiplexed, much easier, I think. I use a single 74141 for the cathodes and high voltage optocoupler, TLP627 (available in single, dual or quad packages) for the anodes with just a single current limiting resistor. I've settled on this circuit design as it has a very low parts count, inexpensive and is very reliable.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: March 05, 2015, 01:54:25 am
content: Quote from: macboy on March 02, 2015, 03:25:19 pm1966:http://www.bigblockmopar.nl/2010/12/chrysler-electroluminescent-dashboard-lighting/

author: nickds1
author_rank: Contributor
timestamp: March 05, 2015, 10:25:47 am
content: Quote from: Alex Eisenhut on March 05, 2015, 01:54:25 amElectro-luminescent (EL) is not the same as VFD - completely different technology:VFDs are essentially triodes where the anode is coated with phosphor and you have a directly heated cathode (the heater) and a control grid.EL displays utilise an optical/physical property of the material being used whereby given the correct stimulus, the material emits light.Interestingly, for years, experimenters have been using VFD displays as triodes - some work quite well into low RF frequencies. More interestingly, Noritake (probably the world's largest producer of VFDs) in association with Korg (the audio effects people), have recently started to make novel audio triodes on their VFD production lines:Many of us will have used Noritake VFDs, and as any fule kno, VFDs can be used as triodes, so maybe Noritake decided to cash in on this or just try to see where it'll end up. They've called it the "Nutube 6P1" (*) - the VFD heritage is obvious for all to see - basically, they seem to have been able to use exactly the same manufacturing technology, specifically in the use of new long-life cathode coatings, and also the same form factor & encapsulation as a traditional VFD. Great idea.They're claiming 30,000 hours of continuous use, only 2% of the power consumption of a traditional triode (e.g. 12AX7) and very small size - 30% of the size of a "conventional vacuum tube", however big that might be. Also claiming "rich in harmonics"...Homepage:http://www.korg.com/us/news/2015/012212/also seehttp://www.synthtopia.com/content/2015/01/29/korg-noritake-introduce-futuristic-nutube-vacuum-tubes/Can't find a datasheet ATM.(*) For some reason, when I first read the name "Nutube", I was taken aback as I read it as "Nut Lube". I need to get out more

author: cprobertson1
author_rank: Frequent Contributor
timestamp: March 05, 2015, 06:25:59 pm
content: Quote from: linux-works on March 04, 2015, 10:03:53 pmThat'd actually be incredibly useful! I'll let you know if I take my tests to the next stage or not - I'm going to do a by-hand mockup this weekend hopefully; if it looks decent I'll give you a shout! We have CNC mills at work I can make use of if it comes to it - should be able to get hold of a 5mm V-Bit or 3mm End Mill. A series of <1mm holes in the shape of a digit doesn't look too bad either!Anyway, I'll PM next week if I need it - I'll reimburse you somehow@Kwass - ooh, thanks for the tip! I'll see if I can't get my circuit diagram reviewed by the community before I put the clock together just to make sure I'm not doing anything daftI don't usually work with multiple voltages at once - can't beat a challenge!@nickds1 + Alex Eisenhut - thanks for all teh info! I do enjoy a good read... followed by a wiki trawl...

author: mikerj
author_rank: Super Contributor
timestamp: March 05, 2015, 08:39:34 pm
content: I think the routed/engraved line for acrylic digits needs to be a lot thinner, under 1 mm wide would be good I suspect. As it stands, the digits are noticeably obscuring each other. A small PCB router could probably do a good job here.The "dotted" lines inJurgen Grau's edge lit nixiesseems to work pretty well.

author: klr5205
author_rank: Regular Contributor
timestamp: March 05, 2015, 09:01:58 pm
content: Re-create the nixie tube construction using electroluminescent (EL) wire!Probably best suited to fairly large characters, since I don't think you can create extremely tight radii.

author: linux-works
author_rank: Super Contributor
timestamp: March 05, 2015, 09:53:02 pm
content: Quote from: mikerj on March 05, 2015, 08:39:34 pmeven though this is not about real nixies, I'm getting curious about this, nowI wonder how good it can look when its well executed.next time I go to the laser cutter place, I'll try some varieties of continuous lines and dotted lines.

author: cprobertson1
author_rank: Frequent Contributor
timestamp: March 06, 2015, 08:45:56 pm
content: Just finished up a run of experiments: mixed results to be fair. Hoping to improve with time though, going to try drilling out a series of 1mm holes in the shape of a letter next time instead of just using a hand router as I did with all but one digit here.Brightness is a problem - can't see the digits if there's strong light (fair enough, I expected that- I was going to mount the acrylic platter against a black background anyway)I've encountered several problems - and came up with several good practices:-Good viewing angle (up to 60-70 degrees I reckon)-Low visibility in bright light (to be expected really- youcansee it, but particularly with the overhead halogen bulb it just gets drowned out by all the white light - going to try putting against a reflective or black background to see if that helps any)-Unable to see digits near back of the platter (see photo).-Etching gives decent brightness-Drilling a series of 1mm holes (spaced between 0.5 and 2mm apart (from the center of the drill) gives better brightness than etching (need to be careful not to distort the acrylic plate if you're doing this! Drill against a hard material and make sure it's clamped down!-Going to try using thinner Acrylic - acrylic must be thin (I'm using 1mm: even less, ideally 0.5mm would give a good combination of fidelity and visibility.-Care needs to be taken when cutting and sanding edges; if the acrylic isn't cut cleanly it doesn't let a lot of light through the edges (which is where our lights are coming from!)-Probably going to need to light it from the top as well as the bottom: or use angled lights to ensure good lighting near the top of the plate.-Putting 30V through an LED because you had the wrong preset on your bench supply breaks the LED. Who'd have thought.Note all pictures are taken under medium lighting conditions (1x cold cathode overhead work lamp + 1x fluorescent at other end of desk - the white balance is all over the place as well because of the visible LED at the bottom (I just used a single LED with a 1mm hole drilled in the end and some tape to try and occlude some of the ambient light)2: drilled - 5 plates (no background)3: etched - 5 plates (no background)7: etched: 10 plates (black background: not light isn't focused on that plate properly, 8 is also slightly visible (can be avoided by better LED placement)9: etched: 10 plates (seen behind 8 plates) - thickness of the plates is causing problems. Problem may be improved with drilled numbering instead of etching (as light from rear plates may travel along holes in front of it: we shall see!)2: etched (before I tried drilling it): 10 plates (black background): note 3 is also partly visible due to bad LED Placement3: etched: 10 plates (black background):note 2 is also partly visible due to bad LED Placement

author: cprobertson1
author_rank: Frequent Contributor
timestamp: March 07, 2015, 01:24:07 pm
content: Does anybody know what the part number for theseLED Filaments(or similar) is?I cannot find datasheets or reliable suppliers for themI might try making my own by soldering 0603 or 1005 LEDs to a wire (or two wires) and coating it all in resin: that way I can make them in arbitrary lengths; we'll see how badly that turns out- but I figured I'd ask around as I'm struggling to find them anywhere excepting weird chinese parketplaces.

author: kwass
author_rank: Frequent Contributor
timestamp: March 07, 2015, 04:58:42 pm
content: Quote from: cprobertson1 on March 07, 2015, 01:24:07 pmHow about this one:http://www.runlite.cn/userfiles/5cjerp755q19k1413258994.pdf

author: codeboy2k
author_rank: Super Contributor
timestamp: March 08, 2015, 04:28:14 am
content: Quote from: cprobertson1 on March 07, 2015, 01:24:07 pmIt would be interesting to break one apart... maybe it's been said already, but I think these are strings of chip LEDs (blue?) in series to get the high voltage, like 60V - 80V and then the tube is white phosphor coated, just like the white LEDs.

author: cprobertson1
author_rank: Frequent Contributor
timestamp: March 14, 2015, 08:11:06 pm
content: QuoteDefinitely interesting! Probably one of the first things I'll do with themIf they look good when mounted in a glass jar in a numeric-display shape I was going to try making a simpler version using a string of SMD LEDs and soldering them (in opposite directions) across two strands of copper wire (like a ladder) - varnishing it all and then twisting it into a helix before coating the entire lot in a transluscent resin (to act as a diffuser - might even try adding some aluminium oxide to aid in the diffusion) (this would perforce put them in a parallel configuration which is not something I'd usually do - I would much prefer to put them in serial, which is unfortunately more complex as it'd involve soldering them all onto one wire and then trimming off the wire between the two pads on the same LED to prevent a short. I'm also not too sure how much strain an SMTIf it works, cool, if it doesnt, meh it was only £1 I wasted (and I'll have a bucketload of SMD LEDs for other projects left over anyway)Anyway - still waiting for my LED filaments to arrive, and the R&D into the sidelit acrylic is going well - going to try drilling holes next: will probably have another prototype by tomorrow!

author: cprobertson1
author_rank: Frequent Contributor
timestamp: March 14, 2015, 11:26:23 pm
content: Tried a the through-hole design: while it doesn't look too bad, it's not bright enough for any real daylight usage... and doesn't look particularly nixie-ish =/ Oh well! Dem's the breaks!And yes, that is a spice jar it's living inIt a decent view when the diffuser and hex-grid aren't mounted - I might keep these in mind for future experiments!Here's a link to this series of experimentsIm going to (temporarily) abandon this line of development while I try playing with LED matrices and diffusers - if I get the masking process right I might actually be able to make quite sharp-looking glowing numerals.I'll need to wait for my SMT LEDs to arrive - and I've also a motor controller to build (just a simple NE555 with a pot for the duty cycle running through a transistor linked to a ON-OFF-ON switch to control motor direction - nothing too fancy) - so it might be next weekend before I post anything else up!

author: cprobertson1
author_rank: Frequent Contributor
timestamp: March 19, 2015, 06:26:46 pm
content: Another quick update:The LED filaments arrived today - been playing with them and much to my chagrin they can't be bent more than 15 degrees before the internal connections break.You can view the teardownhereI believe it's literally just a series of LEDs glued to the metal backing (with holes in the backing) and simple connecting wires going between them (with a limiting resistor in the middle and at one end)Bending it breaks the connecting wire, which is a pity!There are closeups of some of the LEDs - note the double-image is due to the reflectivity of the underlying metal.approximate size of LEDs = 0.3mmAnd as a final note - JEEZ are those little things bright! My retinas are still recovering from when I first powered it on!

author: Richard Crowley
author_rank: Super Contributor
timestamp: March 19, 2015, 11:27:34 pm
content: Quote from: cprobertson1 on March 19, 2015, 06:26:46 pmExactly as I feared.But kwass claimed: "They bend very easily and hold their shape once bent."Maybe the "not breaking" part wasn't important to him?

author: kwass
author_rank: Frequent Contributor
timestamp: March 19, 2015, 11:30:56 pm
content: Quote from: Richard Crowley on March 19, 2015, 11:27:34 pmHer, not him.Those seem quite different from the ones I bought on ebay:http://www.ebay.com/itm/1W-COB-LED-Filament-Light-Bulb-Globe-Candle-Light-Source-Warm-Pure-White-DIY-/151416910080?ssPageName=ADME:L:OC:US:3160(the 4200K ones.)They bend very easily and hold their shape even in a 3mm radius circle. 28 LED's inside each.

author: cprobertson1
author_rank: Frequent Contributor
timestamp: March 20, 2015, 07:08:33 am
content: QuoteI did wonder that - I think these are cheap-arse chinese things that I have. They work great when in a straight line, but those little wire connections don't hold up to much!I think I'm going to get some really small SMD parts and try making my own pre-formed digits using copper wire and a combined metal/wooden jig to solder them on: I'll coat them in Hot Dip Wax for the prototype, and a granular-resin for final design if that works (usually used to protect the brittle carbide tools from chipping in their storage drawers at work: nothing worse than an £800 tool getting chipped because somebody slammed a drawer shut!)Anyway, I'll try making some once I get my SMD parts in (I've yet to place the order as I've got a bunch of other parts to source for the Nixie and the non-nixie clocks in the same order, and I figured I might as well get my clocks right before I do anything else)Bit of a pity I got inflexible ones though! They would have looked pretty nice if they were formed into digits!

author: Richard Crowley
author_rank: Super Contributor
timestamp: March 20, 2015, 10:55:59 am
content: Quote from: cprobertson1 on March 20, 2015, 07:08:33 amHow do they perform if you try to run them at "Nixie" light levels? Do they operate only at "blinding levels"?Do they even light up at lower voltages?

author: cprobertson1
author_rank: Frequent Contributor
timestamp: March 20, 2015, 12:14:56 pm
content: You can drop the voltage quite a bit and they're still visible44-46V was when the light became visible - but the individual LEDs were very easily distinguished - at 46-52V you could look directly at them without your retinas melting, but they were bright enough that you couldn't see the individual LEDs.At 52-60V they used increasingly high current and were too bright to look at. No seriously, those were BRIGHT.At 110-120V they make a lot of smoke and a brief flash reminiscent of the trinity test. They don't smell nice either. I suggest not doing this.(Ps - I was just wondering at what voltage they died at, they were surprisingly stable up to 110V, then the current draw shot through the roof and that was the end of the test-piece.)I'll get a low-voltage picture tonight and show a comparison at the various voltages: though I may need to put a welding visor in front of the camera

author: Zero999
author_rank: Super Contributor
timestamp: March 20, 2015, 01:09:59 pm
content: I doubt they have current limiting resistors. It's more likely they're designed for constant current operation. Open any mains LED lamp and you'll find some sort of current limited power supply, whether be SMPs or just a capacitor in series with a bridge rectifier and a couple of resistors to limit the inrush and discharge the capacitor.Use a 60V to 70VDC power supply and add a current limiting resistor to each LED strip. If you try to run them off a constant voltage, you'll probably find the current shoots up as the temperature rises. This may not cause a problem at low currents but resistors are cheap.

author: cprobertson1
author_rank: Frequent Contributor
timestamp: March 20, 2015, 03:35:39 pm
content: There are two (small) resistors in-line with them (one half-way down the strip and one at the anode).For the regular tests I had an in-line resistor (I think it was 220 Ohms? You can swap the resistor out of it - its just a male/female 4mm banana jack on a board with metal tabs across that I made to allow you to lock a through-hole resistor across it - cheap, and great for testing individual components.)For the death-test it was just a 10R, 10W resistor to I didn't trip the over-current on the power supply.Pretty sure they undergo cascading failure at the high voltage/high current just as you said!I was just death-testing it anyway - I've no real plans to run them at 120V-DC.Well... unless I'm trying to blind somebody of courseThey are surprisingly nice little components - it's a pity they aren't a) cheaper, b) more readily available and in my case c) more flexible (though KWass' looked to solve that issue!)

author: Zero999
author_rank: Super Contributor
timestamp: March 21, 2015, 03:17:30 pm
content: They're reasonably priced when you consider how many LEDs you're really buying.You can build a constant current source from a transistor and a resistor. No base resistor is needed because emitter degeneration makes the input impedance very high: a couple of hundred k.Powering the MCU from 3.3V would reduce the voltage across the emitter resistor so it can be lower, given the same current but the current regulation won't be as accurate.