Author Topic: EEVblog #948 - Nixie Tube Display Project - Part 1  (Read 67085 times)

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Offline EEVblog

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EEVblog #948 - Nixie Tube Display Project - Part 1
« on: November 26, 2016, 12:38:37 am »
Part 1 of an internet connected Nixie tube counter/clock display project.
What are Nixie Tubes? How do they work? How do you drive them?
Selecting a suitable driving solution and parametric searching.

 
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Offline 5n44p

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #1 on: November 26, 2016, 01:25:51 am »
Nixie tubes are awesome!

Few months ago i've "taken apart" a in-14b nixie tube and analyzed it with an electron microscope. I've also acquired the spectrum of the light emitted by the tubes to better understand the light emission phenomenon.

Unfortunately i haven't translated my work to english yet, but maybe you can have a look anyway and try to auto-translate it.
I hope you can find some interesting informations!

Here are the links:
Part 1: www.valerionappi.it/autopsia-di-una-nixie/
Part 2: www.valerionappi.it/autopsia-nixie-parte-due/

EDIT: I managed to get at least the first part translated in english, you can find it here. I hope I can get also the second part translated soon
« Last Edit: January 31, 2017, 10:25:59 pm by 5n44p »
 
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Offline TheRevva

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #2 on: November 26, 2016, 02:06:59 am »
The Supertex (aka MicroChip now) HV507 might fit the bill nicely?
- 64 * latched outputs
- 5V supply
- Comparatively friendly package (0.8mm pitch)
- Push-Pull output capability (but you're only really wanting to SINK current)

The only downside is the price @ US$14.00 each, however, you'd only need a couple which helps somewhat and it might keep the PCB real-estate quite small?.
(With 2 of these you'd have 128 available outputs and, given that each Nixie requires 11 if you include the DP, you could fully drive up to 11 tubes)
 

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Offline EEVblog

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #4 on: November 26, 2016, 03:17:18 am »
 

Offline calexanian

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #5 on: November 26, 2016, 03:28:32 am »
That is common to Nixie tubes. It has to do with the distance of the electrodes. Farther away the more  voltage across the ionization field. In quality tubes The arrangement of the digits is chosen to help bring the illumination level Consistent. A 1 digit for example requires less current than an 8 for the same brightness so it is further away so it's higher voltage drop, therefore lower current will not make the perception of a dim numeral. At least in the well designed ones. The Russian ones I have no idea if they even cared.
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Offline EEVblog

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #6 on: November 26, 2016, 03:40:49 am »
UPDATE: The totom pole output driver isn't work too great. Will cover this in the next video.
 

Offline piranha32

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #7 on: November 26, 2016, 03:44:48 am »
Dalibor Farný has on his YT channel a beautiful video documenting process of production of a nixie tube from the very scratch. It's fairly long, but really worth watching

Offline Macbeth

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #8 on: November 26, 2016, 04:18:26 am »
I'm quite excited. I have a stack of IN-12B's (for some weird reason the IN-12A's cost more despite lack of decimal point!) - I also got some of the IN-15A and IN-15B's which are clearly only of interest to electronic engineers or nerds, and so are perhaps harder to come by, but the same pinout and form factor as IN-12's.

The other reason IN-12's are so cheap as that the Nixie Clock Phools treat them with contempt because of the awful '5' being an inverted '2' - now I actually quite like this. Because it would not have cost the soviet any money at all to have a nicely stylised 5 vs 2 - but some fucking soviet bureaucrat managed to get his input using communist committee economics and save the CCCP billions by flipping the digit upside down... I can imagine him partying with his state provided vodka at what an absolute genius he was for such a simple fix for a problem that didn't exist - Bob Pooforfar has nothing on this guy.  :-DD

Now my plan to run them is by multiplexing and MPSA transistors - I also have a couple of K155ID1 which are nearly as obsolete as 74141.

Ultimately I want this as a desk clock (yawn!), but with a bluetooth or wifi interrupt so any of my other test gear or projects can use it's display as and when needed and make use of the IN-15's  \$\Omega\

I've also got some IN-9 bargraphs. I really need to use them too - while the high voltage is available in the display box. They are high voltage current driven.
 

Offline @rt

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #9 on: November 26, 2016, 06:02:49 am »
With eight digits and a moving decimal point, I’m supposing it has to be a frequency counter :D
 

Offline dave_k

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #10 on: November 26, 2016, 06:11:23 am »
Translation of data sheet for you:

BASIC ELECTRICAL AND LIGHTING PARAMETERS

  • Firing voltage .. 170V
  • Display current for numbers .. 2.5mA
  • Display current for "point" .. 0.3mA
  • Cathode brightness .. 100cd/m2  (not sure of the number 100)
  • Viewing angle .. 30deg

ACCEPTABLE MODES OF OPERATION

  • Power supply voltage (DC or RMS value of the voltage from halfwave rectified AC) .. 200V
  • Maintaining voltage .. 120 - 170V
  • Working current for DC voltage supply
            for numbers .. 2 - 3.5mA
            for "point" .. maximum 0.7mA
  • Average current for 50Hz half-wave rectified supply
            for numbers .. maximum 2mA
            for "point" .. maximum 0.2mA
  • Does not contain precious metals

(Apologies to any Russians if my translation is not good)

I guess the key point from this is not to drive the decimal point with too much current .. you might need an additional series resistor for that segment.
« Last Edit: November 26, 2016, 07:25:47 am by dave_k »
 

Offline adithya.yuri

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #11 on: November 26, 2016, 06:46:07 am »
Hi,

Did a further digging into MCHP parts.

http://www.microchip.com/wwwproducts/en/HV5622
http://www.microchip.com/wwwproducts/en/HV5522

Maybe what you need ?
 

Online SeanB

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #12 on: November 26, 2016, 07:29:37 am »
I remember seeing some Nixie drive circuits that used 30V TTL open collector drivers. They used a 120V supply to drive the tube anode at low current, and the cathodes were connected to a pull up resistor to a 30V rail IIRC, so the drivers only had to do a pull down to ground to turn them on, and they would turn off naturally with the resistor taking the supply below extinguish voltage. Had issues with slight ghosting of segments in bright light ( photoemission on the cathodes doing that) and being a little slow to change digits, but worked well enough with no need for expensive high voltage transistors ( this was stuff designed in the 1970's, when you had TTL or discrete, and high voltage devices over 200V were expensive) abd just used the tube cathodes as switches instead.

A similar circuit was used on RADAR TR switches, though there it was more done to get speed by reducing the charge transferred into the plasma switches, they were run with a high current and this allowed them to turn on faster as they got biased just short of conduction.

The voltages Dave measured on the tube with on segments is usual, they vary according to how close they are to the lit electrode and the overlap area. Try again with a 1M pull down resistor and you will see they all will be lower, and stable. Resistor value has to be high enough to not light the off segments, so often was 1M to 4M7. With the push pull driver I would also recommend using a series low leakage high voltage diode with each segment to make them pull down only, otherwise you will have arcing inside the tube, from the ionised plasma and a high voltage on the next electrode, which is not an allowed thing and will cause ion burn at least and a burnt out tube at worst.
« Last Edit: November 26, 2016, 07:36:08 am by SeanB »
 

Offline calexanian

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #13 on: November 26, 2016, 07:35:56 am »
Its VCE is a little low for this application at only 160 volts but the venerable 2N5551 was made specifically with discharge display devices in mind. We have used them by the many as relay drivers. Good general purpose NPN parts bin transistor to have a handfull of around.

https://www.fairchildsemi.com/datasheets/MM/MMBT5551.pdf
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Offline Chipguy

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #14 on: November 26, 2016, 08:10:20 am »
UPDATE: The totom pole output driver isn't work too great. Will cover this in the next video.

Doh.. I just posted that on Youtube comments:
As far as I know a push pull driver would not work with the Nixie tube. Since the segments are all in a row the current won't be flowing from the grid to the segment but from a segment that is pulled high to the segment that is pulled low. I have a feeling that this is not right.?
Where is that smoke coming from?
 

Offline Barny

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #15 on: November 26, 2016, 09:27:19 am »
Nice video.

Even its way above my max 12V comfort zone.

A little advice:
Don't use the phrase: "I like the 88"
Its a phrase from the eternally liveing in yesterday brown poo.
They use it, because the eigth letter in the alphabet is the initial of theire brown greeting which is now often is used from Trump suporters.

Long talk in short: The 88 is whidely knewn code talk for the in europe forbidden geeting of this right, brown faeces

Sorry for this of toppic, but with my surname, I have to handle this toppic on daily base.
 
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Offline bigdog989

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #16 on: November 26, 2016, 10:05:58 am »
I went through the same process of looking for a driver chip when building a nixie clock (yeah I know this is so typical but figured if I had to have one I had to build it from scratch, none of this kit rubbish)

Needless to say the supertex (microchip) chips were the only ones I could find that offered enough pins and could handle the high voltage.

I settled on the HV5530/HV5630, they offered 32bits, high voltage with latched input and were in an easier to solder package (44-Lead PLCC or PQFP)

Only downside was the 12V logic level and the price ~$10 each!!!!

Cant wait to see which way you go!
 

Offline Artlav

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #17 on: November 26, 2016, 10:29:25 am »
Oh, i made a clock out of these a while ago. :)
Don't have a picture of the finished one, but imagine them in the holes of the pillar there.
Driving them is trivial - there is a specialized HV IC for this - K155ID1.
Just use it, one PIC/AVR, one RTC, and an HV converter.

The datasheet translation above is sufficiently correct.


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Having a life since 2013
 
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Offline mikeselectricstuff

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #18 on: November 26, 2016, 10:29:32 am »
I remember seeing some Nixie drive circuits that used 30V TTL open collector drivers. They used a 120V supply to drive the tube anode at low current, and the cathodes were connected to a pull up resistor to a 30V rail IIRC, so the drivers only had to do a pull down to ground to turn them on, and they would turn off naturally with the resistor taking the supply below extinguish voltage. Had issues with slight ghosting of segments in bright light ( photoemission on the cathodes doing that) and being a little slow to change digits, but worked well enough with no need for expensive high voltage transistors ( this was stuff designed in the 1970's, when you had TTL or discrete, and high voltage devices over 200V were expensive) abd just used the tube cathodes as switches instead.

TI do some drivers with 50V outputs
http://www.ti.com/paramsearch/docs/parametricsearch.tsp?family=analog&familyId=356&uiTemplateId=NODE_STRY_PGE_T#
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Offline SlientK

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #19 on: November 26, 2016, 11:20:00 am »
There is an interesting project on Hackaday, Modular Nixie Display. Definitely worth a read.

https://hackaday.io/project/1940-modular-nixie-display
 

Offline PeterL

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #20 on: November 26, 2016, 11:34:36 am »
I think you can get away without latching shift registers, as long as you can disable the outputs. Just disable outputs, shift new data, enable outputs again. Shouldn't take more than 10uSec, no one will notice the blanking.

And I love this kind of video btw. Gives a nice insight of what designing electronics is about.  :-+
 

Offline EEVblog

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #21 on: November 26, 2016, 12:04:46 pm »
There is an interesting project on Hackaday, Modular Nixie Display. Definitely worth a read.
https://hackaday.io/project/1940-modular-nixie-display

Yes, I had thought about something like that. I have a old 8x8 RGB dot matrix module design that is similar in the ability to cascade
 

Offline Trifu22

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #22 on: November 26, 2016, 12:11:30 pm »
I will send you some sockets for your nixies.
they look something like this:

and a IN 15A

and IN 15B
 
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Offline b_force

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #23 on: November 26, 2016, 01:10:33 pm »
In some cases I have seen zener diodes to clamp the voltage.
That way you can use a 80V shift register.
The only down side is that your tubes are not completely 'off'.
Well in theory, with a typical 170Vdc, 100-90V is not enough to turn the tube on.
It's only not the nicest solution.
Another way is to squeeze the current down (as well). But that's gonna be a bit complicated.

Another idea is using transistor/mosfet arrays.
But ones again, they won't be cheap because of the uncommon voltages.

Dual part arrays are easily available (especially for mosfets) and saves you half the hassle.
Best option, HV5122 also easy to solder
Higher voltage logic inputs are not really a big deal IMO, with serial you only have two datalines anyway
Also heaps of projects on the web with that chip
« Last Edit: November 26, 2016, 01:26:57 pm by b_force »
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Offline schlafli

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #24 on: November 26, 2016, 02:33:45 pm »
The timing of this is pretty good, I've just recently built a 4 nixie board that can be cascaded together.

It uses a K155ID1 for driving the digits and a transistor for the decimal point (since the K155ID1 only has 10 outputs). The transistor is the MMBTA42LT1.

The tubes are multiplexed and the whole board uses a single 595 shift register to control it.

3 of the outputs/bits from the 595 go to a 1 of 4 decoder (2 are tube select, one is enable)
1 bit goes to the decimal point
4 go to the digit select on the K155ID1

It's the first PCB I've ever had made and it probably shows :) I can upload the eagle files if anyone is interested.

Ideally I'd like use it as a multimeter display. I've whipped up a quick demo of what that might look like:



Unfortunately the IN15A tube doesn't have a G, so I had to make do with an M.





I'm using an ESP8266 dev board to drive it, so it's technically internet enabled.
« Last Edit: November 26, 2016, 02:40:29 pm by schlafli »
 
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Offline FxDev

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #25 on: November 26, 2016, 03:34:51 pm »
This is my Nixie Tube Clock.
First I want to use USB to get power and communication.

I used STM32F072 48pin series. It has internal RTC and yes, crystalless USB!
I wrote PID algoritm for 5V to 170V converter and bingo, i did it with classical boost converter and around %98 duyt cycle!
For more information please read my entry about that, unfortunately it's Turkish: http://www.firatdeveci.com/gecmise-donus-nixie-clock/

Dave you have to tell about cathode poisoning.

Then I wrote 00-99 counter demo! God, Nixies response times are so fast! Look at it!



Then after that I did my first clock with using IN12A and IN12B. Also RGB background led display and buzzer for alarm.
Now i am designing very small nixie tube clock it will be around 4.5x4.5cm and will work with only one vertical nixie.
Here is the video of that and some photos.




« Last Edit: December 03, 2016, 10:20:36 pm by FxDev »
 
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Offline Macbeth

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #26 on: November 26, 2016, 06:50:38 pm »
The timing of this is pretty good, I've just recently built a 4 nixie board that can be cascaded together.

It uses a K155ID1 for driving the digits and a transistor for the decimal point (since the K155ID1 only has 10 outputs). The transistor is the MMBTA42LT1.
This is great, pretty similar to what I have been procrastinating, including the transistor for the decimal point. You are using a K155ID1 per 4 nixies too. Where did you get the pins to mount the nixies to? The official sockets are kind of bulky and soldering nixies to the board is bad.
Quote
It's the first PCB I've ever had made and it probably shows :) I can upload the eagle files if anyone is interested.
It looks far better than what I can muster with my ferric chloride and bubble tank setup. Please do publish, but at least in PDF format  :-+
 

Offline Dubbie

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #27 on: November 28, 2016, 12:33:49 am »
Very pleased to see a board level design video again.
 

Offline NivagSwerdna

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #28 on: November 28, 2016, 12:52:26 am »
There are plenty of designs using devices rated at 80V so I think that voltage drop video is very misleading.

If you apply 0V to the pin the segment will glow, if on the other hand you apply 60V to the pin then it will not and there will be negligible current.  That's because 170V-60V isn't enough to ionize the segment.
« Last Edit: November 28, 2016, 08:30:18 am by NivagSwerdna »
 

Offline EEVblog

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #29 on: November 28, 2016, 01:53:11 am »
There are plenty of designs using devices rated at 80V so I think that voltage drop video is very misleading.

Why? it's what I measured.
 

Offline EEVblog

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #30 on: November 28, 2016, 01:55:17 am »
In some cases I have seen zener diodes to clamp the voltage.
That way you can use a 80V shift register.

You can use jelly bean ULN2003's with a zener clamp on the COM pin.
Tossing up if I'll do that or go with a Microchip part.
 

Offline NivagSwerdna

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #31 on: November 28, 2016, 08:28:47 am »
There are plenty of designs using devices rated at 80V so I think that voltage drop video is very misleading.

Why? it's what I measured.

http://www.avrfreaks.net/forum/tut-hard-soft-how-build-nixie-clock?page=all has an explanation of their approach which is done by someone far more capable than myself.  In this configuration they drive the HV5812 with 60V, perhaps using a resistor divider or resistor/zener on the HV supply.

A much simplier solution is probably the HV5622 which ticks all the boxes.
 
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Offline Towger

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #32 on: November 28, 2016, 03:28:26 pm »
I wonder what the pink insulator beads between the digits are made from?   I have a number of the same nixies without the dp and they have white insulators, except for one which has a pink one mixed between them.

May not be wise to breathe in the dust if one got crushed...

BTW the numbers on the side 9010 is the date of manufacture.

 

Offline JoseLog

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #33 on: November 28, 2016, 08:13:40 pm »

Some time ago i found this image of a Panaplex display schematic.
The original site does not have the image available anymore: http://www.glowbug.nl/neon/HowToDriveNixies.html

What's interesting, i think, are the high voltage rails and the clamping diode. I'm not entirely sure about what's going on there, but to me it seems like the 80V rail is acting as a voltage limiter for both upper and lower transistors, so that they never exceed 110V and 80V respectively, neither turned on nor off. Something of that kind may work when using a ULN... type shift register.

Now, in the previos link also explains why there's no need for such a high voltage driver... it sounds reasonable, but has someone implemented it and tested it?
 

Offline boffin

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #34 on: November 29, 2016, 05:00:11 am »
I recently was having a little think about how best to drive IN12Bs for a little project I have on the go, and was considering making a little board with the shift and drivers on it (old school 141s) until I came across this guy's boards: (and he deserves a plug because this is nice stuff) http://www.tayloredge.com/storefront/SmartNixie/

He's got nice tiny boards with on-board drivers and a PIC that you drive with i2c, all the high voltage drivers, and they're cheap cheap cheap.  His socketed IN12 board is $8.45

Even the schematics are available (he uses BSS131 as the HV driver transistor)

Also a nice small/cheap 170 V power supply for $14.  Wasn't worth even considering doing it myself.


« Last Edit: November 29, 2016, 05:01:43 am by boffin »
 

Offline FxDev

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #35 on: November 29, 2016, 08:34:43 am »
I've just finished my one nixie board.
It can also work with USB. It has RGB led, buzzer and IN14 socket.
I will share all files after i comleted my work!

Sizes in mm.


Offline robinb

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #36 on: November 29, 2016, 11:33:30 pm »
I've used Tayloredge PSUs and his version of smartsockets for B7971 to make this beastie :


Details here: https://hackaday.io/project/9155-nixiebot

It communicates with the outside world via twitter :  https://twitter.com/nixiebot   so if you have an account you can make it display something by sending the right commands.

Commands are listed on it's tumblr page: http://nixiebot.tumblr.com/ref but basically you just tweet anything with the hashtag  #NixiebotShowMe then a word and it'll display it and send you back a picture by replying to your tweet. If the word won't fit on the tubes it'll scroll and make a movie instead, some characters can't be displayed so to get a scrolling phrase use something like #NixiebotShowMe this:is:a:long:phrase:but:the:parser:thinks:it:is:a:word:because:no:spaces:and:will:scroll:it:for:you   Though there's a 100 frame limit on the movies due to maximum file upload limits. 

There's a twitter imposed rate limit on how fast a bot can tweet ( no more than 25 times every 15 mins ) so if you all jump on it at once you can expect a delay in reply but they do all get queued up. The queue size is mentioned on the biography bit of the twitter page ( turns out that updating that doesn't count towards the tweet rate limit so it's a useful back channel ).

Next phase is to make a proper case for it, I'm probably going for lasercut perspex pyramid stack with internal lighting, openscad wrangling is going on right now :)

"Big old pile o' python in need of sorting out but it works" code is on github here: https://github.com/Zedsquared/NixieBot 

Have fun!

Cheers,
        Robin.
« Last Edit: November 29, 2016, 11:35:53 pm by robinb »
 
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Offline bills

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #37 on: November 30, 2016, 02:51:21 am »
Dave I don't mean to nit pick your video I loved it.
BUT, L1 is on the side not up-rite.
Layout not that bad.
BTW Mike (threeneurons) is a friend and has many nixie tube kits on his web site. (think pile of poo)
FYI.
bill
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Offline bills

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #38 on: November 30, 2016, 03:03:44 am »
To all this was in reference to the power supply board assembly in the video.
 
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Offline EEVblog

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #39 on: November 30, 2016, 03:33:44 am »
Dave I don't mean to nit pick your video I loved it.
BUT, L1 is on the side not up-rite.
Layout not that bad.

Silkscreen shows both vertical (circle) and horizontal mount.
 

Offline EEVblog

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #40 on: November 30, 2016, 05:12:37 am »
 

Offline NivagSwerdna

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #41 on: November 30, 2016, 11:31:17 am »
Enjoyed Part 2.

It showed the Totem Pole connected to the HV... if you look at some of the designs they instead connect the VPP of the HV drivers to 60V (ish) providing the pre-bias voltage and removing the glow etc from the non-driven elements.  The 60V being provided by either a resistor divider from HV (since the current is small) or alternatively a resistor/zener combination.

When you compare the HV driver with 60V VPP from a zener you get a picture that looks very like the DaveCAD schematic.

The use of the jelly bean is a nice touch and actually 7 drivers is quite nice if you are driving tubes with decimals, for some I have there are left and right decimals needing 12 lines... need additional current limiting on the decimals but it might work, 7x2=14; only 2 wasted per tube when direct driving.
 

Offline mikeselectricstuff

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #42 on: November 30, 2016, 11:54:38 am »
With the totem-pole driver, I wonder if simly leaving the HV pin unconnected would work.
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Offline EEVblog

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #43 on: November 30, 2016, 12:03:22 pm »
With the totem-pole driver, I wonder if simly leaving the HV pin unconnected would work.

I was thinking that. Don't know for sure, would have to try it.
Even if it worked, unless you understand the process of why, not something you'd in a production unit. Fine for a one-off.
 

Offline NivagSwerdna

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #44 on: November 30, 2016, 12:47:14 pm »
With the totem-pole driver, I wonder if simly leaving the HV pin unconnected would work.
Isn't the intention of the bias to bring the non-lit elements to a potential where they will not glow (60v giving 170-60=110v, not enough for a glow), if left to flap in the breeze then they adopt a potential which reflects their nearest element?

Here's an interesting graph... http://www.decodesystems.com/re-how-figure-5.jpg

And the full treatment of how much glow is objectionable etc! http://www.decodesystems.com/re-how-nixies-work.html
« Last Edit: November 30, 2016, 01:03:14 pm by NivagSwerdna »
 
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Offline exile

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #45 on: November 30, 2016, 07:44:14 pm »
An alternative is to use standard high voltage BJT and Charlieplexing.
Then you would get by with about 10 I/O from UC, 10 resistor and 80st BJT.
Maybe not so practical but fun little odd.
 

Offline b_force

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #46 on: November 30, 2016, 09:08:12 pm »
In some cases I have seen zener diodes to clamp the voltage.
That way you can use a 80V shift register.

You can use jelly bean ULN2003's with a zener clamp on the COM pin.
Tossing up if I'll do that or go with a Microchip part.
Yes, that was what I wanted to refer to actually, lol
Although, I'm still not a huge fan of these ULN things.
They are just simple 'crude' driver units, that act as an extra buffer.

This means that you still need heaps of I/Os OR a shift register.
In the end you don't win much at all compared to just a few transistors.
(which you can get in dual or quad arrays for just a few pennies).
Maybe just a tiny bit PCB space, but also not that much (also because you can't drive 10 channels.

I wonder what will happen if you connect the high side of the totem pole just to ground?
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Online Twoflower

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #47 on: November 30, 2016, 09:41:16 pm »
In the Video Dave says it several times it does not matter which digit is on/you're measure. Is this correct? I think it does matter which digit is active and which you're measure. The reasons why I think it does:
  • Each digit has a different surface (I think some Nixies use for the one two parallel wires to increase the visibility).
  • The distance to the anode might have an influence as well (including the other cathodes).
  • It might matter if a off segment you're going to measure is in the path of the electrons to the active one or behind.

But in general your results indicate that there pitfalls. Even if Dave might haven't found the worst case. Still the 120-odd volts might be close I would say. And a few volts more or less doesn't matter as you need to handle with them in a appropriate way.

Keep it going! :-+
 

Offline BU508A

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #48 on: November 30, 2016, 09:49:03 pm »
Probably you'll find some inspiration on this website (it is in German and English):

http://www.nixiekits.eu/

The author of this website has the schematics of his Nixie clocks online and imho they are quite nice.
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Offline robinb

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #49 on: November 30, 2016, 10:36:52 pm »
There's also a forum for nixie clock builders here, it's been a bit quiet of late but has recently undergone a change of admin so might perk up.

http://www.tubeclockdb.com/forum/main-forum.html

Some very knowledgeable people hang out in the neonixie google group too:

https://groups.google.com/forum/#!forum/neonixie-l

Cheers,
       Robin.
 

Offline calexanian

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #50 on: November 30, 2016, 11:17:28 pm »
The only potential problem with this sort of arrangement, and I will use this particular example, is that since you now only effectively have 48 volts differential between your on and off state you have to ensure that the high voltage supply is now enough in voltage that they will completely shut off the numerals when the open collector conducts, but high enough that they will start and come to an acceptable level of illumination. Nixies have a bad habit of changing characteristics as time goes on.
Charles Alexanian
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Offline alank2

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #51 on: December 01, 2016, 02:23:32 am »
One day I'd love to do a nixie project - I have one question:

Is there a cathode poison prevention method that can be done quickly as to not be visible?
 

Offline NivagSwerdna

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #52 on: December 01, 2016, 10:42:12 am »
FWIW the physical design might be interesting too... for example some more modern designs have each tube on a daughter board which is pluggable.. the advantage being that they can be soldered, tested, replaced etc separately...
 

Offline EEVblog

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #53 on: December 01, 2016, 10:48:51 am »
Although, I'm still not a huge fan of these ULN things.
They are just simple 'crude' driver units, that act as an extra buffer.
This means that you still need heaps of I/Os OR a shift register.
In the end you don't win much at all compared to just a few transistors.

Not so.
a) You still need the shift registers unless you have 88 I/O pins available on your micro
and
b) You need 88 transistors + 88 resistors if using BJT

I'd rather have 13 ULN2003's + zeners instead of 88 transistors and resistors.
The ULN2003 combine the transistor and the base resistors in a nice easy to solder package.
A better solution IMO.
 

Offline bktemp

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #54 on: December 01, 2016, 10:57:02 am »
I'd rather have 13 ULN2003's + zeners instead of 88 transistors and resistors.
The ULN2003 combine the transistor and the base resistors in a nice easy to solder package.
A better solution IMO.
Even better: TPIC6A595/TPIC6B595
8bit shift register + 8 channel 50V driver + 50V clamp in one package.
http://www.ti.com/product/TPIC6A595
http://www.ti.com/product/TPIC6B595
 

Offline alank2

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #55 on: December 01, 2016, 01:19:18 pm »
I realize the goal is to use easily obtainable parts, but the nixies themselves are not something you can easily order anyway.  Why not consider the nixie, its socket, and its driver IC all to be in the same boat.  There are plenty of the driver IC's on eBay.  What are the pros and cons of using nixie drivers vs. coming up with a modern solution?
 

Offline Spuddevans

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #56 on: December 01, 2016, 06:58:44 pm »
The only potential problem with this sort of arrangement, and I will use this particular example, is that since you now only effectively have 48 volts differential between your on and off state you have to ensure that the high voltage supply is now enough in voltage that they will completely shut off the numerals when the open collector conducts, but high enough that they will start and come to an acceptable level of illumination. Nixies have a bad habit of changing characteristics as time goes on.

You could always use SN75468N 's (pin for pin compatable with ULN2003's) which are rated for 100V and use 90V Zener.

Tim
 

Offline BU508A

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #57 on: December 01, 2016, 10:50:46 pm »
Dave,

why not use one of these nice chips? They seem to me quite suitable for these Nixie tubes:

- HV6810 from microchip - Datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/20005626A.pdf
  It has 10 channel output, serial input, operating voltage up to 80V (End of life)

- HV5812 from microchip - Datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/HV5812%20C072413.pdf
  It has 20 channel output, serial input, operating voltage up to 80V

- HV518 from microchip - Datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/HV518%20C072413.pdf
  It has 32 channel output, serial input, operation voltage up to 90V

They are all available here:
Mouser:
http://www.mouser.de/Semiconductors/Driver-ICs/Display-Drivers-Controllers/_/N-7zhqdZscv7?P=1yzr6k5

Digikey:
https://goo.gl/z6Nzxu

Aliexpress:
https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20161201144129&SearchText=HV6810
https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20161201144208&SearchText=HV5812
https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20161201144246&SearchText=HV518

On ebay are also several sources available.

Hope, you'll find this help-/useful.

Andreas
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Offline EEVblog

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #58 on: December 01, 2016, 11:50:37 pm »
I'd rather have 13 ULN2003's + zeners instead of 88 transistors and resistors.
The ULN2003 combine the transistor and the base resistors in a nice easy to solder package.
A better solution IMO.
Even better: TPIC6A595/TPIC6B595
8bit shift register + 8 channel 50V driver + 50V clamp in one package.
http://www.ti.com/product/TPIC6A595
http://www.ti.com/product/TPIC6B595

I actually shot a clip of that chip in the original video but took it out of the final video to save time as I thought it was interesting but wasn't suitable due the 50V voltage. I didn't notice it had output clamps!
I think it's winner.
I'm just laying out the schematic now and just placed the ULN2003's, so good timing.
 

Offline calexanian

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #59 on: December 01, 2016, 11:57:27 pm »
The only potential problem with this sort of arrangement, and I will use this particular example, is that since you now only effectively have 48 volts differential between your on and off state you have to ensure that the high voltage supply is now enough in voltage that they will completely shut off the numerals when the open collector conducts, but high enough that they will start and come to an acceptable level of illumination. Nixies have a bad habit of changing characteristics as time goes on.

You could always use SN75468N 's (pin for pin compatable with ULN2003's) which are rated for 100V and use 90V Zener.

Tim

That part looks like a good fit. Hey Dave! go look at those SN75468's. Not quite as cheap as the ULN2803 but the more I think about it I am not comfortable with that 48 volt window.
Charles Alexanian
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Offline Technics

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #60 on: December 02, 2016, 03:26:35 am »
I have a clock on my desk at work and one at home that use the TPIC6B585. They have both been running for over 3 years so I dare day it's just fine used as a nixie driver.

Here's one:


And the other:


Looking forward to seeing what you are going to make with the 8 tubes.
 
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Offline firehacker

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #61 on: December 02, 2016, 06:18:19 am »
I'd rather have 13 ULN2003's + zeners

Funny, this was my first thought when I finished watching Part 1. Then I asked myself: why Dave didn't mentioned this approach? There must be some issue with that. And then I realized what could be wrong with that.

As far as I understand the physics of gas discharge tubes, you have a sort of hysteresis there. To start conduction you need to apply voltage greater than firing voltage (which is 170V for these particular tubes). Than the conduction won't stop until voltage drops below minimal sustaining voltage (which is guaranteed to be not less than 120V according to the datasheet).

Unfortunately, this window (170V – 120V = 50V) is the same as ULN2003 max voltage and therefore is equal or even greater than our clamping voltage.

So, it is possible, that since we "fired" a digit in the tube, we will not be able to turn it off just by switching off corresponding channel of ULN, isn't it?

I mean that when using clamping approach, you are limited to have either 0V or 48.6V on a cathode pin of the tube so that voltage drop is either 170V or 121.4V, and the lowest one is above the minimal guaranteed  turn-off threshold.
« Last Edit: December 02, 2016, 06:33:27 am by firehacker »
 

Offline bktemp

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #62 on: December 02, 2016, 07:16:05 am »
I'd rather have 13 ULN2003's + zeners instead of 88 transistors and resistors.
The ULN2003 combine the transistor and the base resistors in a nice easy to solder package.
A better solution IMO.
Even better: TPIC6A595/TPIC6B595
8bit shift register + 8 channel 50V driver + 50V clamp in one package.
http://www.ti.com/product/TPIC6A595
http://www.ti.com/product/TPIC6B595

I actually shot a clip of that chip in the original video but took it out of the final video to save time as I thought it was interesting but wasn't suitable due the 50V voltage. I didn't notice it had output clamps!
I think it's winner.
I'm just laying out the schematic now and just placed the ULN2003's, so good timing.
Why are you using TPIC6C595 (in your component library drawing video)? They have a breakdown voltage of only 33V instead of 50V for A and B variants and have a different pinout!
 

Offline TheRevva

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #63 on: December 02, 2016, 08:53:38 am »
UPDATE: The totom pole output driver isn't work too great. Will cover this in the next video.
Just out of interest Dave...
What happens if you leave the VPP (HV) input pin of the totem pole driver floating rather than holding it at some specific value?
(Thereby effectively only using the lower half of each totem pole output).
It would at least be an interesting test
 

Offline NivagSwerdna

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #64 on: December 02, 2016, 05:43:17 pm »
I'm struggling to reconcile some of the things I have seen in the videos with some of the things I have read in the past and am assuming this is due to lack of understanding on my part... i.e. an impedance mis-match.

The videos show a fail with a totem pole driver (as found in HV5812) but we know there are solutions which work really well with that device.

I knocked up a quick model to show the state of the device when connected to a 'off' element floating at 120V and a HV5812 like device where VPP is supplied with around 60V from a resistor/zener combo attached to the HV 170V supply.

The crux seems to be the ability of the floating pin to supply current... but given the element is at a potential that is lower than that required to ionise the gap its ability to conduct must be limited...

Is that how it works?

In the diagram I've tweaked a few values (the reference being 62V) and added the 47k as an indication of something that doesn't conduct very well....
« Last Edit: December 02, 2016, 05:49:03 pm by NivagSwerdna »
 

Offline calexanian

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #65 on: December 02, 2016, 06:29:08 pm »
Uh oh. The EEVBlog forum echo chamber is in full effect.

Tim mentioned the SN75468.

Permit me to go on a little rant.

That should have been the end of the selection conversation right there! Its cheap, has a common clamp, has easy drive requirements, and is made as a high voltage replacement for the ULN2003 type circuits. Nobody apart from me even mentioned that Tim found a completely practical suitable part that fits the requirements as laid out. I don't want to get into the psychological discussion of how technical people think but I hate to think what goes on in your design review meetings (assuming you actually work professionally. If not then still take it in the spirit intended) when good ideas and complete solutions are ignored for no apparent reason. This is a close cousin to going over the same design consideration over and over again and when a decision is made, you find yourself going over it again just a few days later and have to re convince everybody of what the solution was all the while wasting time and destroying morale.
Charles Alexanian
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Offline calexanian

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #66 on: December 02, 2016, 06:33:14 pm »
I'd rather have 13 ULN2003's + zeners

Funny, this was my first thought when I finished watching Part 1. Then I asked myself: why Dave didn't mentioned this approach? There must be some issue with that. And then I realized what could be wrong with that.

As far as I understand the physics of gas discharge tubes, you have a sort of hysteresis there. To start conduction you need to apply voltage greater than firing voltage (which is 170V for these particular tubes). Than the conduction won't stop until voltage drops below minimal sustaining voltage (which is guaranteed to be not less than 120V according to the datasheet).


Unfortunately, this window (170V – 120V = 50V) is the same as ULN2003 max voltage and therefore is equal or even greater than our clamping voltage.

So, it is possible, that since we "fired" a digit in the tube, we will not be able to turn it off just by switching off corresponding channel of ULN, isn't it?

I mean that when using clamping approach, you are limited to have either 0V or 48.6V on a cathode pin of the tube so that voltage drop is either 170V or 121.4V, and the lowest one is above the minimal guaranteed  turn-off threshold.

Once again see Tim's recommendation of the SN75468. Its higher voltage rating helps this problem.

Also I love the Cardasian avatar. Is that Garak?
Charles Alexanian
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Offline firehacker

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #67 on: December 02, 2016, 07:17:34 pm »
Once again see Tim's recommendation of the SN75468. Its higher voltage rating helps this problem.
I've seen it — good recommendation. To be honest, I haven't read the topic before posting my comment. After watching "Part 2" video I wanted to leave my comment there on YouTube, but than decided that it's too long for YouTube, so I went here and posted it here. Only after posting it I read the entire topic.

Another thing about my comment is that its goal is not to give a recommendation on a part to be used as driver, its all about why Dave did not highlighted "hysteresis problem" in his video.

Also I love the Cardasian avatar. Is that Garak?
Yep! It was taken from DS9: The Fallen.
« Last Edit: December 02, 2016, 07:34:34 pm by firehacker »
 

Offline Spuddevans

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #68 on: December 02, 2016, 08:09:55 pm »
Uh oh. The EEVBlog forum echo chamber is in full effect.

Tim mentioned the SN75468.

I was unaware of this part, but when reading a datasheet for the ULN2003 it actually said for 100V use see the SN75468 (and SN75469 I think  :-\ )

Quote
I don't want to get into the psychological discussion of how technical people think but I hate to think what goes on in your design review meetings (assuming you actually work professionally. If not then still take it in the spirit intended) when good ideas and complete solutions are ignored for no apparent reason.

That's forum's for you, people will choose what to follow whatever they want to, and why not  :-// I am in the process of designing a Nixie Clock and had been going to use nearly 70 HV transistors and 70 resistors as a means for driving the Nixie's. Then after watching Dave's video and reading this thread I looked into the ULN2003's, that was when I read the datasheet and found the high voltage versions and am going with them now.

But everyone will choose what they want to use, I've been on enough forums (Forii??  :-// ) to realise that arguing my point of view gets me nowhere but feeling all riled up. If I can add to a discussion I will, but I'm not out to convince everyone I've got the best answer (cos usually I dont, and then I have to eat humble pie, and for those who've met me, I don't need to eat any more pies!!  :-DD )

Tim
 

Offline calexanian

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #69 on: December 02, 2016, 09:28:08 pm »
The actor that played Garak was the bad guy in dirty harry.
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Offline NivagSwerdna

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #70 on: December 02, 2016, 09:58:42 pm »
https://threeneurons.wordpress.com/nixie-power-supply/ is a very good read and mentions SN75468 and ULN2003 parts.  It also explains that the required voltage on the OFF cathodes to keep them from glowing is very much a function of tube size... this rabbit hole runs deep.
 

Offline Nobody2

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #71 on: December 03, 2016, 09:24:05 am »
a) You still need the shift registers unless you have 88 I/O pins available on your micro
and
b) You need 88 transistors + 88 resistors if using BJT

I'd rather have 13 ULN2003's + zeners instead of 88 transistors and resistors.
The ULN2003 combine the transistor and the base resistors in a nice easy to solder package.
A better solution IMO.
I would suggest to use the ULN2803 instead of the 2003. So you "only" need 11 ULN's, shift registers and zeners.
 

Offline EEVblog

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #72 on: December 03, 2016, 09:59:08 am »
Why are you using TPIC6C595 (in your component library drawing video)? They have a breakdown voltage of only 33V instead of 50V for A and B variants and have a different pinout!

They have clamping zeners built in.
It will have to be the 50V B series though, otherwise the digits would bleed on with the 30V C series.
« Last Edit: December 03, 2016, 10:39:39 am by EEVblog »
 

Offline alank2

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #73 on: December 04, 2016, 02:02:46 am »
I was reading a page about nixies and have a few questions.

#1 - One page mentioned something about AC power - can nixies be driven with an ac?

#2 - I read that is isn't wise to have it turned off - maybe this was a reference to older nixie type drivers though.  With a newer style higher voltage driver with zener's like has been talked about here, is it ok to have all segments off?

#3 - What is the best way to have an adjustable brightness for nixies?  Given you have a fixed resistor to limit current...

Thanks!
 

Offline alank2

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #74 on: December 05, 2016, 04:44:26 pm »
Anyone have any thoughts about my questions?
 

Offline Spuddevans

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #75 on: December 05, 2016, 05:01:06 pm »
#1 - One page mentioned something about AC power - can nixies be driven with an ac?

You can use half wave rectified AC, but I don't think you can use pure AC.

Quote
#2 - I read that is isn't wise to have it turned off - maybe this was a reference to older nixie type drivers though.  With a newer style higher voltage driver with zener's like has been talked about here, is it ok to have all segments off?

As long as your driving circuitry is fine with seeing the main HV voltage (170-200v), or you have a voltage clamp system to limit the higher voltage to one that is safe enough level to not exceed your driving circuit, then it's ok to have all segments unlit.

Quote
#3 - What is the best way to have an adjustable brightness for nixies?  Given you have a fixed resistor to limit current...

There may be a number of ways, more experienced Nixie builders will hopefully chip in, but while you have a fixed current limit resistor, it may be possible to design a means of varying the HV voltage, and thus varying the current drawn by the Nixies, and thus varying the brightness. (though I suspect that this method would have a limited range of brightness, nowhere near the range you would get using PWM and LED's)

Tim
 

Offline alank2

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #76 on: December 05, 2016, 06:47:24 pm »
Thanks Tim!
 

Offline Macbeth

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #77 on: December 05, 2016, 09:41:32 pm »
You can use half wave rectified AC, but I don't think you can use pure AC.

If I recall the IN-xx Russian tubes are indeed designed to run using simple un-filtered/un-smoothed half wave 240VAC, and this should lead to longer life than a 170VDC supply?  (Cathode poisoning?) :-//

Direct rectified mains is of course quite insane for a hobbyist but as bigclivedotcom shows pretty much all the great unwashed who enjoy pound shops/dollar stores have plenty of devices around that can injure or kill just to shine a pretty LED. I haven't seen a rise in deaths from them, but they are often shit like a ripoff 2A Samsung knock-off charger I had went up in magic smoke.

Using proper design I would be happy to use half wave from the mains providing all the normal precautions are used X/Y capacitors, PTC, slots in PCB etc. The Nixies PCB should be isolated by opto-isolators too, though wifi and bluetooth modules are now so cheap why bother?

Low current so just use two 240/12 transformers back to back for safety during development. Switch to direct mains for final implementation.  :-+
 

Offline b_force

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #78 on: December 06, 2016, 09:14:17 am »
Why are you using TPIC6C595 (in your component library drawing video)? They have a breakdown voltage of only 33V instead of 50V for A and B variants and have a different pinout!

They have clamping zeners built in.
It will have to be the 50V B series though, otherwise the digits would bleed on with the 30V C series.
The TPIC6B596 or the TPIC6B595?
There is even a TPIC6A595, but that one is a bit more expensive.
Nice packages and easy all in one solution, but pretty big packages though, 96mm²
You will need 11 of them (for 88 connections), which is 1056mm²

Just pure on board space/total surface area;
44 dual BJT arrays (like the PMBTA42DS/MMDTA42) incl some resistors (which you practically can put anywhere you want) uses less board space for 88 connections.
The BJT arrays together are only 198mm², which is equivalent to two HV shift registers.
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Offline alank2

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #79 on: December 06, 2016, 03:53:18 pm »
Those SmartNixie boards shown above use BSS131's for switching.

In terms of dimming, if you were NOT multiplexing, could you simply adjust the on time in milliseconds?  If you were doing 60 Hz, that would be 16.67 mS.  You could leave it lit for 1 mS out of 16...

Also, for cathode poison prevention, can you light the unused digits periodically for small run times so they are not on long enough to be visible.  Would that be sufficient?
 

Offline FxDev

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #80 on: December 06, 2016, 08:07:14 pm »
Why nobody thinks about convert high voltage with using microcontroller  |O  :-//

We have very good uCs today to convert voltage, so don't play with dimming issues, just decrease the voltage from 170V to for example 130V. Or you can convert it high value.

Offline SNGLinks

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #81 on: December 06, 2016, 09:29:54 pm »
I hate the look of the 5 digit.

This is much better.
 

Offline Towger

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #82 on: December 06, 2016, 09:39:47 pm »
Why nobody thinks about convert high voltage with using microcontroller  |O  :-//

We have very good uCs today to convert voltage, so don't play with dimming issues, just decrease the voltage from 170V to for example 130V. Or you can convert it high value.

That's what this design does, uses an MEGA328-P (arduino) to multiplex one 74141/K155ID1 to drive 6 tubes and at the same time control a boost converter for the high voltage.
http://www.open-rate.com/Downloads/NixieClockInstructionManualRev4V42.pdf
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Offline robertbaruch

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #83 on: December 06, 2016, 10:33:14 pm »
I agree with some of the previous posters: The 50V clamp is very iffy. If the maintaining voltage is 120V-170V, then when a digit is on and you attempt to turn it off, having a 120V differential across the tube isn't guaranteed to turn it off.

This was my circuit. I use a MAX6922 VFD driver [datasheet] with its output set to 60V for "off". That gives the tube 110V across, which is low enough to guarantee turn-off. You don't need an output clamp: the  voltage at any output will be driven to either 0V or 60V.

Granted, it's a PLCC, which isn't exactly breadboard-friendly. The HV518 [datasheet] is equivalent in DIP package (and can go up to 90V, so you have an even better safety margin).
 

Offline EEVblog

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #84 on: December 06, 2016, 11:18:16 pm »
I agree with some of the previous posters: The 50V clamp is very iffy. If the maintaining voltage is 120V-170V, then when a digit is on and you attempt to turn it off, having a 120V differential across the tube isn't guaranteed to turn it off.

I'm using 160V in my design with 50V clamps for this reason. You'll see an update and quick test of this in my next video.
 

Offline bjrn

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #85 on: December 07, 2016, 11:17:26 am »
Very nice project with a good roundup about the specific parts and details for this clock :-+. I will definitely follow all of your videos and posts regarding this project.

I also build myself a nixie clock based on the IN12b for my bachelor thesis over a year ago. Never had the time to do a little wrap up about the build. I also went with the ESP8266, which connects to my wireless network and gets the time via NTP, as a main controller, some 595 shift registers and discrete MMBTA42 transistors and a simple switchable high voltage step up power supply with a cheap MC34063. It is okay for only four tubes. Your solution seems to be much better for a higher number of nixie tubes. As the eagle layout designer was used as freeware, I was limited to the board size and I also wanted to "manufacture" the PCBs with the toner transfer method on my own at home. So I decided to make a one sided, modular design. The power supply or controller could be swapped in future, if I want to upgrade it or make it more efficient.

The PCB quaility of the main display module is not as good as the one for the ESP. A laminator does the work much better, than a normal iron with uneven pressure. I hope I will have some time to improve the layout and make some new PCBs again, but it works and the glow of the tubes looks so nice in contrast with modern computers and stuff on my desk.
« Last Edit: December 07, 2016, 11:21:26 am by bjrn »
 

Offline EEVblog

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #86 on: December 07, 2016, 11:26:09 am »
PART 3:
 
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Offline NivagSwerdna

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #87 on: December 07, 2016, 01:50:50 pm »
Keeping the elements OFF once they have been ON seems to be the challenge (since their sustain voltage is much lower than the initial conduction voltage) so the first test probably wasn't that relevant but the subsequent test of turning the 7 on and off seems to prove that at 160V with 50V clamp is do-able.  Might be worth repeating that second test with all digits in turn.
« Last Edit: December 07, 2016, 04:46:58 pm by NivagSwerdna »
 

Offline twam

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #88 on: December 07, 2016, 06:00:39 pm »
Dave, if you use D5 of the ESP8266 module for your CLK and D7 for the data you could use its build-in HW SPI the get data out. As you're not using the pins for anything else, there's nothing to loose :)
 

Offline AustinTxBob

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #89 on: December 07, 2016, 07:10:43 pm »
It looks like all of the Nixie drivers are getting the same data fed to them.  How is the appropriate data being pushed to each one?
 

Offline bktemp

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #90 on: December 07, 2016, 07:15:34 pm »
It looks like all of the Nixie drivers are getting the same data fed to them.  How is the appropriate data being pushed to each one?
They are connected in series: All data get shifted into the first ic. After 8 clocks, the first bit appears at the output of the first ic and enters the second ic.
So for the 11 ics 88bits need to be clocked out. The first 8 bits end at the last ic. The last 8bits at the first ic.
 

Offline AustinTxBob

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #91 on: December 07, 2016, 07:26:14 pm »
It looks like all of the Nixie drivers are getting the same data fed to them.  How is the appropriate data being pushed to each one?
They are connected in series: All data get shifted into the first ic. After 8 clocks, the first bit appears at the output of the first ic and enters the second ic.
So for the 11 ics 88bits need to be clocked out. The first 8 bits end at the last ic. The last 8bits at the first ic.

So 88 clock pulses (DCLK?) and then the other clock (RCLK) is pulsed to push all of the data out to the tubes?
 

Offline bktemp

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #92 on: December 07, 2016, 08:07:14 pm »
So 88 clock pulses (DCLK?) and then the other clock (RCLK) is pulsed to push all of the data out to the tubes?
Exactly.
Because all the data get shifted through all shift registers, having the additional latch/register is really useful, otherwise wrong data would appear on the outputs while shifting.
 
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Offline robertbaruch

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #93 on: December 07, 2016, 08:52:30 pm »
With regard to the voltages... well, if it works, it works. I do like that Dave validated that 120V wasn't sufficient to turn off the digits, and that 160V was sufficient to turn them on. Still, I'd rather see good engineering practice and conform to both the turn-off voltage (<120V) and turn-on voltage (>=170V). But again, like I said, if it works, it works.
 

Offline robertbaruch

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #94 on: December 07, 2016, 08:54:52 pm »
BTW, I really enjoy Dave go through the design process. I think this should be a regular feature: "Dave builds X".
 

Offline Pentium100

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #95 on: December 07, 2016, 09:10:40 pm »
This part got me a bit confused. With the two zener diodes arranged like this and a sufficiently high voltage across the output, wouldn't the gate of the transistor be at 20V? Well, if the gate is at 20V then the transistor starts to conduct and the voltage would drop, but wouldn't this result in the transistor being partially open?
I am most likely missing something, just cannot figure out what since obviously the chip has to work.
 

Offline bktemp

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #96 on: December 07, 2016, 09:21:27 pm »
This part got me a bit confused. With the two zener diodes arranged like this and a sufficiently high voltage across the output, wouldn't the gate of the transistor be at 20V? Well, if the gate is at 20V then the transistor starts to conduct and the voltage would drop, but wouldn't this result in the transistor being partially open?
The mosfet will start conducting at a much lower voltage than 20V. Normally you wouldn't need the 20V Z-diode because the mosfet will conduct and limit the drain voltage whenever it goes above gate threshold voltage (probably somewhere between 1V and 4V) + z-diode voltage. The 20V z-diode protecting the gate is only needed for fast transients being applied to the drain.
So yes, the mosfet will be conducing slightly, but only as much as needed to keep the drain voltage below 33V. As soon as the voltage goes below 33V, it stops conducting.
Basically the mosfet acts as a power amplifier for the z-diode increasing its power handling capabilities.
 

Offline alank2

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #97 on: December 07, 2016, 11:29:20 pm »
Really enjoying these videos - good job Dave!!!
 

Offline Pentium100

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #98 on: December 08, 2016, 04:56:42 am »
So yes, the mosfet will be conducing slightly, but only as much as needed to keep the drain voltage below 33V. As soon as the voltage goes below 33V, it stops conducting.
Basically the mosfet acts as a power amplifier for the z-diode increasing its power handling capabilities.
That's interesting. But doesn't this mean that the clamp voltage is around 33V (the value of the "top" zener) and not 50V (both zener diodes combined)?
 

Offline niekvs

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #99 on: December 08, 2016, 01:49:45 pm »
The SN75468 indeed seems like a much better choice (together with a 90V clamping zener). That way, the design will have a lot bigger margin and not depend on these specific types of Nixie tubes. E.g., say someone wants to use this same design but use different nixies, the 50V clamp may well fall short. And since the SN75468 is also easily available, I don't see a reason to use the part with the built-in zeners. You can then also just use the datasheet strike voltage of 170V or 180V without a problem, rather than lowering it to 160V "because it works with these specific nixies I have in hand". It's better to have a comfortable margin.
 
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Offline Macbeth

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #100 on: December 08, 2016, 11:07:45 pm »
I agree, a more general solution for a wider variety of Nixies would suit viewers wanting to use the circuit for their own use.
Yes... now tell me wilfred, where does it end. What particular parameters would you be happy with?

Now pray tell how you come up with a universal "Nixie" PCB tube layout that will suit IN-12's but also every other possible "Nixie" on the planet?
 

Offline rs20

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #101 on: December 09, 2016, 12:56:04 am »
I agree, a more general solution for a wider variety of Nixies would suit viewers wanting to use the circuit for their own use.
Yes... now tell me wilfred, where does it end. What particular parameters would you be happy with?

Now pray tell how you come up with a universal "Nixie" PCB tube layout that will suit IN-12's but also every other possible "Nixie" on the planet?

+1, but going even further I'd say the goal for a video like this should be about teaching the process; the specific circuit that comes at the end is more or less irrelevant. After all, if viewers want a completed, ready-to-go schematic, they can just find a schematic on the internet. All of the discussion and detail in the videos would be totally wasted on such viewers if they ended up just using the exact same gerber files as Dave.
 

Offline niekvs

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #102 on: December 09, 2016, 10:48:51 am »
I agree, a more general solution for a wider variety of Nixies would suit viewers wanting to use the circuit for their own use.
Yes... now tell me wilfred, where does it end. What particular parameters would you be happy with?

Now pray tell how you come up with a universal "Nixie" PCB tube layout that will suit IN-12's but also every other possible "Nixie" on the planet?

I agree that obviously you can always find improvements, but this particular one doesn't have any meaningful drawbacks and has quite a benefit, and it teaches the viewer to engineer with good margins rather than 'hack' your way around an issue by (in this case) lowering the strike voltage and relying on a specific type of component. A more generally applicable solution, with no additional cost, would seem to make sense in this case and is good practice in general.

You can also turn your argument around, and ask yourself: which particular parameters or margins would you NOT be happy with? When you are designing something, do you also prefer components that, should at one point they are no longer available, cannot easily be replaced because the margins don't allow for this?

Of course, Dave can do what he wants: it's his project :) Also, it's clearly a one-off, so these arguments may not be very meaningful.
 

Offline rs20

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #103 on: December 09, 2016, 10:57:53 am »
niekvs, you seem to be forgetting that your proposed solution requires separate darlington arrays and shift registers. This requires double the number of components, which is a far more concerning downside that the non-existent downsides of reducing the supply from 170 to 160V.
 

Offline niekvs

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #104 on: December 09, 2016, 11:15:28 am »
niekvs, you seem to be forgetting that your proposed solution requires separate darlington arrays and shift registers. This requires double the number of components, which is a far more concerning downside that the non-existent downsides of reducing the supply from 170 to 160V.


This is true, but a couple of 595's can be had for pennies. Personally, I would multiplex it to limit the amount of components (e.g. in pairs of 2 or 3). But I agree it is a small downside. But to say that reducing the strike voltage to 160V is not a downside, I disagree: it's outside of the datasheet spec for the IN-12. I'd much rather operate my components within spec and have a more general solution that can be used for different types of nixies. If you prefer to operate your components out of spec, well I guess we disagree on that one. Just don't be surprised if it fails e.g. even when using a different batch of IN-12s.
 

Offline b_force

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #105 on: December 09, 2016, 11:58:40 am »
There are many solutions to a certain problem.
As I posted a little bit back, if it's about just board size and total surface area, the current solution is also not optimal.
For the same reason I personally don't like a SN75468 (or similar) buffer. It's an all in one package, yes. But you do need an extra shift register.

What I personally would like to see, is some answers to questions that are still open. There were some ideas and suggestions with totem pole outputs for example.
We still don't really know if they are usable with maybe some tricks. Maybe they are not going to be used in this specific project, but we are already that far that it doesn't take much to at least check out some possible solutions, just because it is interesting or helpfull for future projects.
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Offline splin

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #106 on: December 10, 2016, 02:29:12 pm »
A simple way to reduce the pre-bias voltage would be to connect another output from the microcontroller to the power supply feedback resistor network to change the supply voltage. It could normally run at say 140V to ensure that off elements don't glow even with a relatively low pre-bias voltage, but periodically raised to 170V+ for 50us or so to strike/ionize any digits which have changed or failed to strike earlier. Raising the anode voltage isn't strictly necessary, but it speeds up the strike time which depends on some random event such as a charged particle initiating ionization. In the dark it could take a second or more (including never) for a digit to strike but that would be unusual.

The anode resistor values would probably also need to be reduced in value as the anode voltage will rise considerably when no digits, or only the DP is lit, requiring a higher pre-bias voltage to prevent unlit elements glowing. Eg. Dave's 22k will cause a 22V rise in anode voltage when the 1.6mA digit current reduces to the .6mA or less of the DP.

You could probably get away with 33V drivers if all the Nixies are reasonably matched, but in general at least 50V would be required, even if you modulate the supply voltage, to allow for the relatively wide range of operating voltages of different Nixie types or changes over their lifetime.

Nixies are actually current controlled devices so ideally constant current drivers would be used. Using voltage drive + resistors is a proxy which is cheaper/more convenient but actually a bit tricky to design to accommodate all variances in tube characteristics, power supply and driver voltage and component tolerances etc. without having a high voltage supply of 180V+ and high pre-bias of 70V+.

The Burroughs application notes are helpful - see N102: http://worldpowersystems.com/archives/Burroughs/.

[EDIT] Here is another useful Burrough's datasheet/applications note: http://www.decadecounter.com/vta/pdf2/burroughs_616.pdf
« Last Edit: December 11, 2016, 02:16:53 pm by splin »
 

Offline HugoPT

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #107 on: December 11, 2016, 04:45:10 pm »
I'm following this nixie tube awesome project but I can't understand how this the clamping circuit works :'(
What is the theory involved on this clamping circuit to  drop the voltage?Maybe it would be a great topic to "fundamentals friday"


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Offline Spuddevans

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #108 on: December 12, 2016, 10:49:58 am »
What is the theory involved on this clamping circuit to  drop the voltage?Maybe it would be a great topic to "fundamentals friday"

This is how I understand it,

The problem is that many control IC's are limited on the voltage they can withstand, so switching close to 200V is out of range for most generic ic's. The way we are driving the Nixies is with "Low-side" switching, ie switching the "Ground", so when the nixie element is OFF the switching device (either a IC or a HV transistor) will "see" 170-190v across it's collector-emitter.

That's no problem if your output device is rated for that voltage, but most IC's are not. The way some IC's have got round it is to put a diode in each driver transistor and bring that out onto it's own terminal, you can then attach a Zener diode on that pin that is within the voltage rating of the output transistor(along with a resistor connecting the zener to HV+ to bias it). What this does is provide a means to "Clamp" the max voltage "seen" by the output transistor in the driving chip to the value of the Zener diode. This voltage is still below the voltage needed to turn on the Nixie.

Hope this explains it, I'm sure others can explain it better.

Tim
 

Offline rs20

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #109 on: December 13, 2016, 11:07:20 pm »
What is the theory involved on this clamping circuit to  drop the voltage?Maybe it would be a great topic to "fundamentals friday"

The problem is that many control IC's are limited on the voltage they can withstand, so switching close to 200V is out of range for most generic ic's. The way we are driving the Nixies is with "Low-side" switching, ie switching the "Ground", so when the nixie element is OFF the switching device (either a IC or a HV transistor) will "see" 170-190v across it's collector-emitter.

That's no problem if your output device is rated for that voltage, but most IC's are not. The way some IC's have got round it is to put a diode in each driver transistor and bring that out onto it's own terminal, you can then attach a Zener diode on that pin that is within the voltage rating of the output transistor(along with a resistor connecting the zener to HV+ to bias it). What this does is provide a means to "Clamp" the max voltage "seen" by the output transistor in the driving chip to the value of the Zener diode. This voltage is still below the voltage needed to turn on the Nixie.

That's a fine explanation, but I'd add a bit more numeric detail to clarify a few things. Specifically,
  • If the Zener clamps the IC output voltage to, say, 50V, and the power supply is set to 160V, then the Nixie tube will have a voltage of 110V (160V - 50V) across it. The voltage across a device is all that ever matters.
  • 110V is below the voltage required to turn on the Nixie tube, so it will appear to be off. Also important to consider if the Nixie tube is off, very little current will flow through it, so our Zener clamp will not have to dissipate very much power.
The point is that you can put 110V across a Nixie tube, and it'll appear to be totally off and only a tiny amount of leakage current will come through. We can use this to our advantage by switching from 110V (off) to 160V (on), and we can achieve these relative voltages by hooking an IC that outputs 0 - 50V on one side of the nixie tube, and a fixed 170V supply on the other.

I'm actually not sure how this would be turned into a FF, it's just a combination of knowing the non-linear VI curve of a Nixie tube and a super-basic application of Kirchoff's Voltage Law, which already has an FF video:



 
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Offline NivagSwerdna

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #110 on: December 21, 2016, 03:42:20 pm »
A trivial question to some....

What physical size anode resistors would you use? SMD small-ish resistors seem to be pretty low wattages... through hole for the anode resistors?

Looks like my 0805 pad layout isn't going to cut it.  |O  2512?
« Last Edit: December 21, 2016, 04:06:03 pm by NivagSwerdna »
 

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #111 on: December 24, 2016, 12:35:33 am »
All this talk of 160 vs 170V etc, it appears that even as low as 130V is well enough for these IN-12 nixies, e.g. http://mightydevices.com/?p=379

Very nice using a micro to produce the switching and feedback to maintain that 130V HV :-+ Also working with multiplex too.

Just because a CCCP datasheet states 170V (but with no min/max to go with it) doesn't mean it is a fact. Frankly I believe the 170V was stated because it happens to be the half wave rectification of typical Soviet 240 VAC mains. No more, no less. The cheapest dirtiest possible HV DC at the time in Soviet Union.
 

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #112 on: December 24, 2016, 12:53:39 am »
Looks like my 0805 pad layout isn't going to cut it.  |O  2512?

According to  tomasz.watorowski of MightyDevices he used 0805 and 0603.  :-+
 

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #113 on: December 30, 2016, 10:47:16 am »
Hello,

I post here and said finished to design PCB and yesterday I finally got it!

STM32F072 48pin MCU control everything; RTC, 5V to 170V converter, USB connection ext. It has buzzer and also RGB led. I used 300V sot23 NPN. Its dimension is only 4.5x4.5cm. I can be used with bigger Nixies too.

I will share all details after I finished my job.

 
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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #114 on: December 31, 2016, 05:13:47 pm »
i started playing with nixies around the same time as the first video appeared - i already had some IN-4 nixies and a power supply based on this https://threeneurons.wordpress.com/nixie-power-supply/ following the suggestions from Threeneuron i went with an Darlington array (w/ 47v zener) because i didn't feel like soldering 10 SOT transistors for each nixie tube (went with direct drive instead of multiplexing just for fun). I already knew i was going to use a 595 since i wanted to make something that could be daisy chained.

After watching the third video i saw the TPIC6B595 and i thought i could replace the 595 + uln2008 with it but because the layout was done already i decided to send it to OSHpark. Couple of weeks i received the boards the 595 + uln2003 works almost great exept the clamp voltage (47V) at least for my in-4 nixies is too low and when the nixie is not driven by the uln2003 some of the digits are partially lit (see link https://goo.gl/photos/dRfTq2JFU1gpqUnq6). Dropping the supply voltage from 180V to 165V made the effect less visible but still present i guess going with SN75468 and higher clamp voltage will fix the problem, anyway im glad now that i didn't go with the TPIC since it has a clamp voltage is only 50V.
« Last Edit: January 01, 2017, 09:11:13 am by vladco »
 

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #115 on: January 02, 2017, 10:00:48 pm »
While waiting Dave, I will finish my second nixie clock with using dummy 300V sot23 NPN transistors   :bullshit:

Here is the first demo video.


Offline b_force

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #116 on: January 03, 2017, 12:09:03 am »
While waiting Dave, I will finish my second nixie clock with using dummy 300V sot23 NPN transistors   :bullshit:

Here is the first demo video.


Nice with the little SOT NPN's. Which ones did you use?
Where can I find the project on your website btw?
(little difficult to search if people don't speak/read that language :P )
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Offline FxDev

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #117 on: January 03, 2017, 07:57:20 am »
Nice with the little SOT NPN's. Which ones did you use?
Where can I find the project on your website btw?
(little difficult to search if people don't speak/read that language :P )

I didn't share this tiny project yet because it is not done yet.  :-BROKE
I will share all details when i finished. You can look my other nixie clock here: http://www.firatdeveci.com/gecmise-donus-nixie-clock/
I don't know Google Translate is good or not for my website.

I use "MMBTA42-HT" with 1k base resistor.

Nobody asked me but I think nobody cares about how I can convert 5V to 170V that small area :)

Offline b_force

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #118 on: January 03, 2017, 11:32:41 am »
There are multiple ways to convert 5V to 170V.
I have seen people using all sorts of things.
Easiest way is using a little step-up transformer.
You can also just use a boost converter with just an inductor.
Or just use a ucontroller as a boost converter (which i think is clever, because you're using one anyway).
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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #119 on: January 03, 2017, 03:16:22 pm »
There are multiple ways to convert 5V to 170V.
I have seen people using all sorts of things.
Easiest way is using a little step-up transformer.
You can also just use a boost converter with just an inductor.
Or just use a ucontroller as a boost converter (which i think is clever, because you're using one anyway).

Yes, we generally use uCs in our projects so why can't we use them like a simple boost converter.

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #120 on: January 07, 2017, 07:54:32 am »
just a small update regarding my other post regarding the clamp voltage, after changing the clamp voltage to 75V (replacing also the ULN2003 with an SN75468) tubes are completely off when they are not driven.

@FxDev can you share your design for HV power supply driven from the MCU ?
 

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #121 on: January 07, 2017, 08:13:20 am »
@FxDev can you share your design for HV power supply driven from the MCU ?

Of course!
I use TC4427 mosfet driver because my MCU is working with 3.3V. Of course we can use other methods but this is the  easiest way for me.
On the other hand, input caps are 1206 package 100nF and 1uF ceramic. Output cap is 2.2uF/250V. L1 is 330uH, I also tried 100uH to 680uH with no problem. I use PID algorithm for control this converter. Duty is around %70-80 when nixies are working. R24 is 150k/1206 and R25 is 2k2/0805. D1 is SK120 200V schotket diode.

I finished programming, now I'm writing small PC program to configure my nixie clocks. Few days later I will publish all!


« Last Edit: January 07, 2017, 08:15:22 am by FxDev »
 
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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #122 on: January 07, 2017, 09:44:03 am »
Of course!
I use TC4427 mosfet driver because my MCU is working with 3.3V. Of course we can use other methods but this is the  easiest way for me.
On the other hand, input caps are 1206 package 100nF and 1uF ceramic. Output cap is 2.2uF/250V. L1 is 330uH, I also tried 100uH to 680uH with no problem. I use PID algorithm for control this converter. Duty is around %70-80 when nixies are working. R24 is 150k/1206 and R25 is 2k2/0805. D1 is SK120 200V schotket diode.

I finished programming, now I'm writing small PC program to configure my nixie clocks. Few days later I will publish all!



thanks for sharing, few more questions, switching frequency, saturation current of the inductor, max output power  :D
« Last Edit: January 07, 2017, 11:42:39 am by vladco »
 

Offline boffin

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #123 on: January 08, 2017, 07:04:14 pm »
I'm just using some of Taylor Edge's smart nixies (need to get some more), and made a backplane using some perfboard.  (the analog discovery is monitoring the i2c feed in this shot)


 

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #124 on: January 08, 2017, 07:59:05 pm »
I managed to get my Christmas Nixie clock project mostly completed now.  I use a 62v zenner and HV5812s and have no glow on any element apart from the lit one.  Just need to laser cut an acrylic case now.
 

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #125 on: January 09, 2017, 06:28:09 am »
@FxDev can you share your design for HV power supply driven from the MCU ?

Of course!
I use TC4427 mosfet driver because my MCU is working with 3.3V. Of course we can use other methods but this is the  easiest way for me.
On the other hand, input caps are 1206 package 100nF and 1uF ceramic. Output cap is 2.2uF/250V. L1 is 330uH, I also tried 100uH to 680uH with no problem. I use PID algorithm for control this converter. Duty is around %70-80 when nixies are working. R24 is 150k/1206 and R25 is 2k2/0805. D1 is SK120 200V schotket diode.

I finished programming, now I'm writing small PC program to configure my nixie clocks. Few days later I will publish all!


There is an easier way for the gate driver (this is also a little overkill), and that's just a simple npn/pnp totem pole.
You can do that with two transistors, or with something like a ZXGD3002E6.
Widely used in Class-D power amplifiers.

If you don't need much power I think a combination with a step-up transformer would work a little better.

I used a ucontroller based voltage regulator before. It worked pretty decent, only a few interrupt problems.
I personally would use a switching frequency around 50-100kHz.
Don't forget a parallel diode with the gate resistor btw! Improves switching off times and efficiency significantly.
(better is even a active transistor/diode combination)
I personally also would use a snubber circuit parallel to the mosfet.
« Last Edit: January 09, 2017, 06:31:24 am by b_force »
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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #126 on: January 09, 2017, 01:50:38 pm »
Hello again,

Everyday I am designing 10kW to 800kW UPS systems so this is not problem for me to control with MCU.  :-DMM
My switching frequency is 16kHz. My MCU is working at 48MHz and so I have 3000 count resolution. My inductor saturation current is ~300-400mA when I use 330uH ~4.5x4.5mm. I didn't measure my maximum output power but it depends on how you can switch on/off your mosfet. That's why i use TC4427. With one nixie my duty cycle is around ~%50-65 and with 4, it is around %85-95. So it came to around maximum. You can say 170V with 4-5mA ~1W input power with losses.

Everyone thinks diode with parallel gate resistor is good but I think this depends on what you are using. This diode helps switching off mosfet very fast but what about di/dt!? We know VL=L*di/dt. So if you turn off or on your mosfet very fast, you can get very big voltage spike! :bullshit: So be very careful!  :-/O

BTW, I finished my one nixie clock and Its PC program  :popcorn:
Now i'm waiting Dave's Nixie Multimeter!



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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #127 on: January 09, 2017, 02:51:08 pm »
I'm just using some of Taylor Edge's smart nixies (need to get some more), and made a backplane using some perfboard.  (the analog discovery is monitoring the i2c feed in this shot)

you are also using his power supply module ? looks cool anyway, keep us posted :)

There is an easier way for the gate driver (this is also a little overkill), and that's just a simple npn/pnp totem pole.
You can do that with two transistors, or with something like a ZXGD3002E6.
Widely used in Class-D power amplifiers.

If you don't need much power I think a combination with a step-up transformer would work a little better.

using a ZXGD3002E6 isn't the same thing as using a TC4427 ? there are basically doing the same thing.

I managed to get my Christmas Nixie clock project mostly completed now.  I use a 62v zenner and HV5812s and have no glow on any element apart from the lit one.  Just need to laser cut an acrylic case now.

looks cool, anywhere we can read about your project ?

My switching frequency is 16kHz.

that frequency is in the audible range, aren't you getting a high pitch sound from your supply ? 
 

Offline b_force

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #128 on: January 09, 2017, 03:38:44 pm »
There is an easier way for the gate driver (this is also a little overkill), and that's just a simple npn/pnp totem pole.
You can do that with two transistors, or with something like a ZXGD3002E6.
Widely used in Class-D power amplifiers.

If you don't need much power I think a combination with a step-up transformer would work a little better.

using a ZXGD3002E6 isn't the same thing as using a TC4427 ? there are basically doing the same thing.

Yes, but cheaper and much smaller :)
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Offline FxDev

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #129 on: January 09, 2017, 09:21:03 pm »
No, i used closed type inductor and doesnt make any sound :)

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #130 on: January 14, 2017, 10:35:20 pm »
----
« Last Edit: January 19, 2017, 05:35:43 am by FxDev »
 

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #131 on: January 18, 2017, 08:52:39 pm »
Finally I finished my One Clock Nixie project!!

Here is the video!!
Nixies finished for me now :)

For everything (it's turkish, please use translate): http://www.firatdeveci.com/gecmise-tekrar-donus-one-nixie-clock/



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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #132 on: January 24, 2017, 08:24:35 am »
FWIW I came across a really nice Nixie design (I have no association with the vendor) on EBAY

eBay auction: #162198121548

This design uses HV5812 and has some nice elements which can be seen on the schematic which is the github repo linked

https://github.com/afch/NixeTubesShieldNCS314/blob/master/Nixie_Clock_Shield_NCS314%20v1.1.pdf

I'm glad I didn't see that before I built mine.... I would have saved myself a lot of fun!
« Last Edit: January 24, 2017, 08:30:43 am by NivagSwerdna »
 

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #133 on: January 24, 2017, 02:10:26 pm »
Isn't the intention of the bias to bring the non-lit elements to a potential where they will not glow (60v giving 170-60=110v, not enough for a glow), if left to flap in the breeze then they adopt a potential which reflects their nearest element?

Here's an interesting graph... http://www.decodesystems.com/re-how-figure-5.jpg

And the full treatment of how much glow is objectionable etc! http://www.decodesystems.com/re-how-nixies-work.html

Is the term "pre-bias" used for two different concepts? I found this one, which Dave is using, too, for protecting the FET, because the voltage can't go higher than 50V:



But when the FET is turned off, the cathode for the digit is floating. I guess the best solution would be a push-pull output, with the full 170V when on and 0V when off? Because if the FET has some leakage, a current can flow, like the website NivagSwerdna cited describes and this could cause some glow of the digits that should be off. If I understand it correctly, the 50V pre-bias in the circuit above doesn't help with the glow, because of the diodes and the FETs can still leak and pull-down the voltage lower than 50V even when switched off.

I did some tests with a Z560M Nixie tube (was cheap on eBay, but doesn't look as nice as other Nixie tubes, which can cost a lot) and a BSS131 MOSFET (nice chip, allows to control the gate with 3.3 V logic level voltage). I connected two digits, 5 and 3. When digit 5 is on, I can measure 54V at the drain of the turned-off MOSFET for digit 3. But maybe this is my multimeter? It has 10 megohm input impedance (a BM257S) and I measure the same voltage when I disconnect the cathode from the MOSFET. When I add a 1 megohm pull-up resistor from 170V to digit 3, I can measure 130V (resistor at the anode side is 22k).

I don't know what this means. Do I need a pullup-resistor? This is the datasheet of the MOSFET. I think I don't need the bias for protecting it, because Vds is 240V (and it still works after some time testing it), but I can't find the leakage current in the datasheet when it is off. I think it is very low, because the voltage doesn't change when I connect the MOSFET drain to the cathode. But maybe a high pull-up resistor like 10meg would be still useful, just to make sure that the cathode has a clearly defined high voltage level when the MOSFET is off?

Sorry for dumb questions, I don't know much about analog electronics, but these Nixie tubes are fascinating.
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Offline FrankBuss

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #134 on: January 27, 2017, 10:22:33 am »
This is the datasheet of the MOSFET. I think I don't need the bias for protecting it, because Vds is 240V (and it still works after some time testing it), but I can't find the leakage current in the datasheet when it is off.

Found it: 10 nA leakage current at 25°C. That's nice, even with 240 V drain/source it would be equivalent to a 24 gig ohm resistor. So I guess it is ok to use a 10 meg ohm pullup resistor, just to prevent it from floating.

Would this work, i.e. safe to operate with the MOSFET and the Nixie tube, and no glow of turned-off digits, regardless of which Nixie tube I use? Of course, the anode resistor and voltage has to be adjusted for other types.



The 0 ohm resistors is to adjust digits individually, if necessary when they are too bright compared to the other digits.

PS: First time I tried to use KiCad, sometimes a bit strange and the GUI is not like other graphics programs (copy-and-paste doesn't work as expected, when you move a component, the wires don't get extended, the question to discard the schematic when I close it instead of asking if I want to save it, strange way to create new libraries and copy components etc.), but this is offtopic here.
« Last Edit: January 27, 2017, 04:13:33 pm by FrankBuss »
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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #135 on: January 29, 2017, 03:10:47 am »
Dave mentioned he wants to show some information from the internet. I wrote some scripts for a NodeMCU board which can do this, and more:

https://www.eevblog.com/forum/projects/how-to-setup-a-rapid-development-environment-for-nodemcu-and-lua-scripts/msg1123918/

The example loads the time from the internet, but you can load any data you want. And no cloud service or complicated webservice with JSON etc. stuff needed, which seems to be hip at the moment. Just plain HTTP and a 2-line PHP script on your own webserver.
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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #136 on: February 02, 2017, 03:04:01 pm »
Hi folks I hope it is ok for me to post a few questions regarding nixies here,

I have had some NI-4 tubes laying around for ages, and I have finally started a project where I am going to use them. I have a nixie power that can deliver 80-200v, which is perfectly, as I seem to need between 150-170v to drive the nixie.

Everything seems to be in order, and I have successfully lit the letters with test-leads. The problem is that I cannot find any information about how to correctly use the NI-4 since it has 2 anodes and 1 shield. Most nixie tube projects seems to use tubes that only have 1 anode.

So the first question is. I know the two anodes are for odd and even digits. But do I really have to cut the anode-power of the odd digits when using the even digits, and vice versa? It really complicates the circuit more than I really want. :/

Next question: I have read somewhere that the shield input should have a ~50v input. Do I need to create a custom constant-voltage circuit to keep this pin at 50v? Or is it something you only would do to prolong the life of the tube a bit? If so, anyone have any tips on how to do it the "KISS" way?

Anyone have any ideas/answers for me?  :D

Project info:
I was planning on driving 6 tubes with the usual K155ID1 russian chips (74141 equivalent) and some 74HC595 bit shift registers that in turn gets connected to an external mcu. But if they need custom odd/even handling, I'd have to add another 74HC595 and some transistors etc, for handling the anode-power of each tube, I guess.
 

steverino

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #137 on: February 16, 2017, 06:55:51 am »
Is this project dead?
 

Offline NivagSwerdna

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #138 on: February 16, 2017, 12:27:31 pm »
So the first question is. I know the two anodes are for odd and even digits. But do I really have to cut the anode-power of the odd digits when using the even digits, and vice versa? It really complicates the circuit more than I really want. :/
http://www.tube-tester.com/sites/nixie/data/in-4/in-4-sh2.htm suggests use just pin 4 when not in  biquinary mode??
Next question: I have read somewhere that the shield input should have a ~50v input. Do I need to create a custom constant-voltage circuit to keep this pin at 50v? Or is it something you only would do to prolong the life of the tube a bit? If so, anyone have any tips on how to do it the "KISS" way?
That's a topic of some debate!  :-DD If you follow an existing K155ID1  design then you should be OK.

 

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #139 on: February 17, 2017, 09:14:44 am »
 

Offline haakonn

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #140 on: March 01, 2017, 08:45:55 am »
So the first question is. I know the two anodes are for odd and even digits. But do I really have to cut the anode-power of the odd digits when using the even digits, and vice versa? It really complicates the circuit more than I really want. :/
http://www.tube-tester.com/sites/nixie/data/in-4/in-4-sh2.htm suggests use just pin 4 when not in  biquinary mode??

Ah. I was not aware that it was a mode. I thought it was something to do with a version of the nixie that had to be connected that way if it had the extra pins. Now that I checked what biquinary was, I think I understand. It is an encoding that lets you use less connections to the nixie I guess. Thanks for the input! I think the reason I was thinking it wasn't a mode was that I have tried connecting it once, and I seemed to have to switch which anode to use, to get some of the digits to light up, even if I was using that "common" anode at pin 4. Maybe it has to do with the screen or something? Ah well. My memory is getting foggy, I think I just have to wire it up again and test again.

Next question: I have read somewhere that the shield input should have a ~50v input. Do I need to create a custom constant-voltage circuit to keep this pin at 50v? Or is it something you only would do to prolong the life of the tube a bit? If so, anyone have any tips on how to do it the "KISS" way?
That's a topic of some debate!  :-DD If you follow an existing K155ID1  design then you should be OK.

I am not following any specific circuit, but have looked at a lot of them. The problem is that most of them use other nixie tubes that do not have shield input as far as I have seen, or that they at least doesn't have both an anode pin and a shield/screen pin. So I haven't seen enough designs to make up a decision if it is needed or not. Maybe my googling skills are getting worse. :p
 

Offline intabits

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #141 on: April 21, 2017, 04:48:22 pm »
Hello All. I've just joined and this is my first post.

Has anybody actually made this project, or used IN-12 nixies with TPIC6B595 drivers? Does it work?
I have, but things are not well...
Just to test that the basics were OK, I only fitted 2 tubes and 2 chips, and tried to get some response by driving it from an Arduino.

I was just sending a single continuously incrementing byte, and as expected the digits were flashing every which way, and it was looking good - for about 30 seconds.
Then there was a loud crack and a spark (seemed as if it came from a nixie), the display went sick for a few seconds and died.
I can't see any obvious damage, but at least one of the chips is dead, and so is one or more of: Arduino/FTDI adapter/USB port.

So I'm wondering:-
* Is the TPIC6B595 up to the job after all?
* Are my cheapish Chinese chips just substandard fakes?
* Did the test, which was driving many digits at once, stress the chips to failure?

I'd like to know if this has been done with success.
Then if the first option above is true, I can achieve success simply by avoiding the last two.

« Last Edit: April 21, 2017, 04:50:40 pm by intabits »
 

Offline intabits

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #142 on: April 22, 2017, 10:36:27 am »
No comments? I'll plough on regardless...

Just tested the two nixie tubes, one is fine, but the "9" on the other does not light up completely. And all its digits are a little dimmer than the first tube.

So I checked the 22k dropper resistor, and it's gone out to 51k. That explains the dimness, and possibly the partial lighting of the 9 also.
It's just an 0805 SMD part, so when multiple digits were drawing current through it, maybe it was overloaded and that is what exploded (though it doesn't look damaged).

I'll try replacing the resistor and the dead TPIC6B595(s), and this time ensure that only one digit per nixie is active. Maybe that'll work...
 

Offline FrankBuss

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #143 on: April 22, 2017, 11:30:58 am »
So I checked the 22k dropper resistor, and it's gone out to 51k. That explains the dimness, and possibly the partial lighting of the 9 also.
It's just an 0805 SMD part, so when multiple digits were drawing current through it, maybe it was overloaded and that is what exploded (though it doesn't look damaged).

That's really bad, have you done the math? 0805 has like 0.1 W power rating. If you need like 3 mA per digit for smaller Nixie tubes, the voltage drop for the 22k resistor is 66 V, which result in 0.2 W, and that's just for one digit. It won't survive this for long.
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Offline boffin

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #144 on: April 22, 2017, 05:24:15 pm »
I'm just using some of Taylor Edge's smart nixies (need to get some more), and made a backplane using some perfboard.  (the analog discovery is monitoring the i2c feed in this shot)

you are also using his power supply module ? looks cool anyway, keep us posted :)

Yes, i bought his dual-in line power module and it works very well. Can power 8 nixies from 12 volts no problem.  Final project will likely be only 7 (due to constraints of the box I'm going to put it in).  I'll post more pics as I get around to it on my blog.

Only gotchas with the Taylor Edge stuff is some of his documentation is a little odd such as referring to I2C addresses as separate addresses for read/write (0x10/0x11) as opposed to the more normal (0x08 read 0x08 write), where it's an address and then a bit for read/write.  Also his DIP switches tables are 0=on, because he's thinking the reading into the micro and they're switches shorting to ground.  Once you look at the schematic and diagrams you can figure this out, but it took me longer than it should have to understand his mindset
 

Offline intabits

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #145 on: April 23, 2017, 11:21:13 pm »
That's really bad, have you done the math? 0805 has like 0.1 W power rating.

No, obviously I haven't! (I don't do much SMD, and I have been caught out on that one before)
In my defense, it seems like Dave used 0805's (but possibly 1206) in EEVblog #974, and I didn't bother checking.

Anyway, replaced the resistor, and the nixie has come good now.
If it still proves to be a problem (and it seems that it will), I'll bodge on some larger resistors.
But I want to check some voltages/currents/powers first.

I would still like to know if anyone has actually driven IN12 nixies with TPIC6B595's, and how well it works.
 

Offline Mr Smiley

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #146 on: April 25, 2017, 08:03:21 pm »
Is this project dead?

Yep looks like it's another dead duck, like his power supply and other started and never finished projects.

I'm going over to BigClive's - regular INTERESTING content - looks like Dave's dragging his heals and raking in the hits for doing nothing - probably from past supporters hoping to find content which isn't here anymore - Everybody fades out eventually. The forum is the only thing keeping people coming back. It's clear his interests are elsewhere.

 :-\
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Offline NivagSwerdna

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #147 on: April 25, 2017, 10:23:45 pm »
That's really bad, have you done the math? 0805 has like 0.1 W power rating.
No, obviously I haven't! (I don't do much SMD, and I have been caught out on that one before)
In my defense, it seems like Dave used 0805's (but possibly 1206) in EEVblog #974, and I didn't bother checking.

Anyway, replaced the resistor, and the nixie has come good now.
If it still proves to be a problem (and it seems that it will), I'll bodge on some larger resistors.
But I want to check some voltages/currents/powers first.
Actually I made the same mistake on my display board using 0805 footprint but solved it by using double decker... one R on top of another and doubling the value, no magic smoke yet.
I would still like to know if anyone has actually driven IN12 nixies with TPIC6B595's, and how well it works.
There seem to be some people on the interweb who have done it. https://groups.google.com/forum/#!topic/neonixie-l/NTRfqU8ASvc
Personally I went for HV5812 (might use HV5622 if I do it again)
 

Offline intabits

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #148 on: April 26, 2017, 11:00:30 am »
...using 0805 footprint but solved it by using double decker... one R on top of another and doubling the value...
That's a good trick, thanks for the tip. As I say, I haven't done much SMD and I just watched a video where this was done, so it looks like this is one the "tricks of the trade"
I've actually mounted my nixies on individual daughter boards rather than using pins, so there is ample room for a non-smd resistor anyway.
These daughter boards also have two small neons, individually selectable and with a separate anode resistors. (my niixes have no decimal point, so the neons can do that, as well as make colons for a clock and upper/lower=AM/PM indicators)
This requires 12 bits/nixie so 3 SRs serve 2 tubes, with 3 sets in all.
Using the daughter boards leaves a clear channel on the mainboard underneath for the shift registers and allows short, very neat traces (4 up, 4 down) to the nixie sockets.

There seem to be some people on the interweb who have done it. https://groups.google.com/forum/#!topic/neonixie-l/NTRfqU8ASvc
Personally I went for HV5812 (might use HV5622 if I do it again)
Thanks. I'll look into those.
« Last Edit: April 26, 2017, 11:04:31 am by intabits »
 

Offline EEVblog

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #149 on: May 01, 2017, 01:48:07 pm »
PART 5:
« Last Edit: May 02, 2017, 01:04:25 am by EEVblog »
 

Offline prof

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #150 on: May 01, 2017, 03:20:11 pm »
"This video is private."
 

Offline 5n44p

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #151 on: May 01, 2017, 03:49:29 pm »
Why is the video gone private?  :scared:
 

Offline Barny

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #152 on: May 01, 2017, 03:55:53 pm »
The big nixie tube industrie raided Dave's lab & took down his video. ;)
 

Offline Fliz

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #153 on: May 01, 2017, 04:07:59 pm »
He messed something up, again?
 

Offline nikomo

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #154 on: May 01, 2017, 04:14:53 pm »
Two options for speculation, either he deleted it because he was being a major dummie with the OSH Park stuff, or because he didn't want the video to be interpreted as some sort of promotional content because he mentioned what PCB fab he got a coupon from.
 

Offline RGB255_0_0

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #155 on: May 01, 2017, 05:13:24 pm »
Two options for speculation, either he deleted it because he was being a major dummie with the OSH Park stuff, or because he didn't want the video to be interpreted as some sort of promotional content because he mentioned what PCB fab he got a coupon from.
Likely this. I still have it open and have rewatched it a couple of times looking for anything that might be perhaps personal info or sensitive and didn't notice anything so likely you're right.
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Offline TheAmmoniacal

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #156 on: May 01, 2017, 05:34:51 pm »
One viewer says he saw Dave's office address and personal phone number in the video, seems likely not to want that public. I didn't catch it when I watched it though.
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Offline RGB255_0_0

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #157 on: May 01, 2017, 06:16:49 pm »
One viewer says he saw Dave's office address and personal phone number in the video, seems likely not to want that public. I didn't catch it when I watched it though.
Yes, just spotted it on the order page. But I doubt it's the address he's worried about, more the telephone number  :palm:
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Offline TheAmmoniacal

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #158 on: May 01, 2017, 06:18:32 pm »
One viewer says he saw Dave's office address and personal phone number in the video, seems likely not to want that public. I didn't catch it when I watched it though.
Yes, just spotted it on the order page. But I doubt it's the address he's worried about, more the telephone number  :palm:

If I remember correctly he did get some calls by random viewers last time they found his number.
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Offline RGB255_0_0

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #159 on: May 01, 2017, 06:21:51 pm »
Will be interesting the next live show  :popcorn:
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Offline timgiles

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #160 on: May 01, 2017, 06:32:37 pm »
Hope a rework of the video is put up soon.
 

Offline Towger

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #161 on: May 01, 2017, 06:47:27 pm »
Not the first time... Dave has tweeted delivery tracking numbers, which reveal all then entered on the couriers site!
 

Offline EEVblog

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #162 on: May 02, 2017, 01:05:53 am »
Video is back up.
 
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Offline mrpackethead

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #163 on: May 02, 2017, 05:01:06 am »
Dave Junior is wrong.  PCBWay do really do the job in those time frames.

Allpcb.com and pcbway.com are both owned by the same chinese company.  ( JDBPCB )     They developed the interface for PCBway and it has been so sucessfull that they are now using it to front end about 40 other chinese PCB factorys.  ( yes its bizzare )    I've found the service to be really really good,  ( i've typicaloly buying 4 layer boards ).. The stencils are awesome as well.  theres just no reason not to use them at all.

Allpcb are also offering some other interesting services like front panels and also access to lots of low cost parts.

No they dont' pay me. I'm just a happy customer..   


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Offline mrpackethead

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #164 on: May 02, 2017, 09:36:47 am »
One viewer says he saw Dave's office address and personal phone number in the video, seems likely not to want that public. I didn't catch it when I watched it though.
Yes, just spotted it on the order page. But I doubt it's the address he's worried about, more the telephone number  :palm:

Daves phone number is  7662    When Did Sydney still have four digit phone numbers.
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Offline prof

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #165 on: May 02, 2017, 11:25:37 am »
After looking at the video I checked out pcbway.com. They're quite cheap and fast and offer a ton of options were others would tell you to go fish... I really have to try them some time when I need some of those special options.

Having said that my current projects all go to elecrow. They might not be always the cheapest but they have a very good service and even the prototype boards are of professional quality (no mouse bites but everything professionally milled and no random silkscreen rubbish many others would put on the boards :--) and the turnaround of the cheapest shipping option is already quite swift (under 10 calendar days to Germany) and they usually include extra boards for free if the panel is not yet full.
 

Offline NivagSwerdna

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #166 on: May 02, 2017, 11:39:15 am »
Having said that my current projects all go to elecrow.
Mine too.  Very happy with them and all have worked first time with zero issues.  The photo as they dispatch them is a very nice touch.  +1 for Elecrow.
 

Offline thm_w

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #167 on: May 02, 2017, 07:28:22 pm »
Would be interesting to know the discrepancy between pcbshopper and the sites, seems to be related to the fast turn times, I PM'ed Bob to ask him to comment.
Wish I could use the DHL shipping option, its not bad but then you add ~$16 duties/taxes on that and it adds up quickly (ancient canadian import laws).

As for the Altium footprint thing, there is clearly something wrong. But most likely it did warn him when he was doing the board update, that it would change the package from 0603 to through hole (whatever the footprint was called).
I've had Altium replace an 0603 with another footprint named 0603 (I guess it was higher on the libraries list), but never a different name.
 

Offline rea5245

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #168 on: May 02, 2017, 08:37:58 pm »
As the owner of PCBShopper.com, I would like to clear up some of Dave's confusion.

At the 36 minute mark, Dave is using PCBShopper and saying some nice things about it - thank you! But at 36:15 he asks why more companies aren't showing up when he selects 5 business days, because he knows that many companies offer a 5 day lead time. The reason is that PCBShopper's day selection field is labeled "Boards arrive in:", and the Total Days column in the results has a footnote that says:

Quote
"Total Days" is a worst-case estimate of the number of business days it will take for you to receive your PCBs, i.e. manufacturing time plus shipping time, excluding weekends and holidays. If the manufacturer says "5-8 days", we quote 8 days.

So PCBShopper is telling you lead time plus shipping time, and so very few companies can deliver the boards to your door in 5 business days. Contrary to what Dave says at 36:40, PCBShopper is showing the complete picture. As for whether PCBShopper should be taken as gospel: since Dave is an atheist, my goal is to be better than gospel with him. :-)

At 37:30, Dave is puzzled that PCBShopper didn't show him the same price as PCBWay. The reasons for that are: 1) PCBShopper is quoting the Express 24 hour price, since Dave asked for the boards to arrive at his door in 7 business days and DHL shipping quotes "3-5 business days". 2) PCBWay adds a PayPal fee to their price at checkout, and PCBShopper is taking that into account. (Regarding points 1 and 2, in PCBShopper's results for PCBWay there's a note that says "Select the express 24hours build time. Price includes PayPal fee." And 3) PCBWay is showing US dollars and PCBShopper is showing Australian dollars (there's a pull-down control at the top of the PCBShopper price results that lets you switch to US dollars).

At 37:40, Dave says "PCBShopper has failed us". That's an unfortunate choice of words. In fact, PCBShopper has provided the correct results.

- Bob Alexander
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« Last Edit: May 02, 2017, 08:43:30 pm by rea5245 »
 
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Offline mrpackethead

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #169 on: May 02, 2017, 08:44:32 pm »
Sadly, i kind of agree with Dave.  Theres times when PCBshopper adds confusion.. While it does provide you with a lot of information its not always in a way that is sensible.     The other issue is that its often possible to further reduce prices by lookign at various options at a particular vendors site..



As the owner of PCBShopper.com, I would like to clear up some of Dave's confusion.

At the 36 minute mark, Dave is using PCBShopper and saying some nice things about it - thank you! But at 36:15 he asks why more companies aren't showing up when he selects 5 business days, because he knows that many companies offer a 5 day lead time. The reason is that PCBShopper's day selection field is labeled "Boards arrive in:", and the Total Days column in the results has a footnote that says:

Quote
"Total Days" is a worst-case estimate of the number of business days it will take for you to receive your PCBs, i.e. manufacturing time plus shipping time, excluding weekends and holidays. If the manufacturer says "5-8 days", we quote 8 days.

So PCBShopper is telling you lead time plus shipping time, and so very few companies can deliver the boards to your door in 5 business days. Contrary to what Dave says at 36:40, PCBShopper is showing the complete picture. As for whether PCBShopper should be taken as gospel: since Dave is an atheist, my goal is to be better than gospel with him. :-)

At 37:30, Dave is puzzled that PCBShopper didn't show him the same price as PCBWay. The reasons for that are: 1) PCBShopper is quoting the Express 24 hour price, since Dave asked for the boards to arrive at his door in 7 business days and DHL shipping quotes "3-5 business days". 2) PCBWay adds a PayPal fee to their price at checkout, and PCBShopper is taking that into account. (Regarding points 1 and 2, in PCBShopper's results for PCBWay there's a note that says "Select the express 24hours build time. Price includes PayPal fee." And 3) PCBWay is showing US dollars and PCBWay is showing Australian dollars (there's a pull-down control at the top of the PCBShopper price results that lets you switch to US dollars).

At 37:40, Dave says "PCBShopper has failed us". That's an unfortunate choice of words. In fact, PCBShopper has provided the correct results.

- Bob Alexander
  PCBShopper.com
 
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Offline rea5245

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #170 on: May 02, 2017, 08:48:31 pm »
Sadly, i kind of agree with Dave.  Theres times when PCBshopper adds confusion.. While it does provide you with a lot of information its not always in a way that is sensible.     The other issue is that its often possible to further reduce prices by lookign at various options at a particular vendors site..

If you tell me how it adds confusion, what is not sensible, and give examples of how vendors' sites let you further reduce prices, I might be able to address those issues. But based on what you've written, I really don't know what to do.

- Bob Alexander
  PCBShopper.com
 

Offline eV1Te

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #171 on: May 02, 2017, 09:09:51 pm »
As the owner of PCBShopper.com, I would like to clear up some of Dave's confusion.
...
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Its unfortunate if Daves conclusions were inaccurate since it would probably affect a lot of his subscribers opinions about your site. I have never used PCBShopper before so I cant add anything to the discussion.

But luckily you took some time to write here to explain some of the comments, maybe you should also reply directly to the Youtube comments in order to reach as many viewers as possible.
Thanks for your honesty and quick reply here on the site I promise that I will try your site the next time I am ordering PCBs. :)




 

Offline rea5245

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #172 on: May 02, 2017, 09:19:12 pm »
But luckily you took some time to write here to explain some of the comments,

It wasn't luck. A kind soul sent me a private message to let me know about the video.

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Offline FrankBuss

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #173 on: May 02, 2017, 10:43:28 pm »
Maybe Dave could add some annotations in the video, and write something in the description? I know, nobody reads the description :D but at least every new viewer could see the annotation.
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Offline rs20

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #174 on: May 02, 2017, 10:52:33 pm »
Oof, this seems like a particularly unfortunate PEBKAC -- pcbshopper being labelled as being all over the place, while it's the varied pricing structures of all the PCB companies that are all over the place and pcbshopper is quite explicitly cutting through all that variation. In other words, the fact that Dave was so confused by pcbshopper's results is exactly why you should use it, rather than why you shouldn't. Tough situation  :(

Maybe Dave could add some annotations in the video, and write something in the description? I know, nobody reads the description :D but at least every new viewer could see the annotation.

Annotations don't exist anymore, and were never visible on mobile anyway.
 

Offline FrankBuss

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #175 on: May 02, 2017, 11:19:38 pm »
Annotations don't exist anymore, and were never visible on mobile anyway.

Right, I just tried it and got this message: "The ability to add or edit annotations ended May 2". So they disabled it today. Good timing. But they can do "cards", which work even on mobile. But looks like no free text annotation is possible with cards. I guess not a technical limitation :palm:
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Offline rea5245

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #176 on: May 02, 2017, 11:35:38 pm »
In other words, the fact that Dave was so confused by pcbshopper's results is exactly why you should use it

And why you should take it as gospel! :-) :-)

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Offline mrpackethead

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #177 on: May 03, 2017, 05:22:24 am »
Are the design files avaiable for this somwhere dave?

I think some of the PCB Fabs would love to send you pcbs in the mail bag and then you can tell us how good they are .
On a quest to find increasingly complicated ways to blink things
 

Offline rs20

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #178 on: May 03, 2017, 05:33:06 am »
I think some of the PCB Fabs would love to send you pcbs in the mail bag and then you can tell us how good they are .

Yeah, nah, I don't think I'd trust that. I'm sure they'd pay unusually close attention to getting their solder mask alignment especially perfect, making a special point of not marring the silkscreen with fab identifiers, etc; if not straight up making an order from PCBZone or Eurocircuits and passing it off as their own. Either way, assuming that it was completely representative of a random hobbyist order seems risky.

Also, if you want quite an old comparison (it's out of date, PCBZone now supports several colours and ENIG finish):

 

Offline mrpackethead

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #179 on: May 03, 2017, 06:20:39 am »
I think they would be settng them selves up for a massive amount of trouble if they did that. These guys woud'tn wnat to set an expectation for a product that was streets ahead of what they make.. It woudl just end up with a LOT of HATE>
On a quest to find increasingly complicated ways to blink things
 

Offline Macbeth

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #180 on: May 04, 2017, 10:06:30 pm »
As the owner of PCBShopper.com, I would like to clear up some of Dave's confusion.

At the 36 minute mark, Dave is using PCBShopper and saying some nice things about it - thank you! But at 36:15 he asks why more companies aren't showing up when he selects 5 business days, because he knows that many companies offer a 5 day lead time. The reason is that PCBShopper's day selection field is labeled "Boards arrive in:", and the Total Days column in the results has a footnote that says:

Quote
"Total Days" is a worst-case estimate of the number of business days it will take for you to receive your PCBs, i.e. manufacturing time plus shipping time, excluding weekends and holidays. If the manufacturer says "5-8 days", we quote 8 days.

So PCBShopper is telling you lead time plus shipping time, and so very few companies can deliver the boards to your door in 5 business days. Contrary to what Dave says at 36:40, PCBShopper is showing the complete picture. As for whether PCBShopper should be taken as gospel: since Dave is an atheist, my goal is to be better than gospel with him. :-)

At 37:30, Dave is puzzled that PCBShopper didn't show him the same price as PCBWay. The reasons for that are: 1) PCBShopper is quoting the Express 24 hour price, since Dave asked for the boards to arrive at his door in 7 business days and DHL shipping quotes "3-5 business days". 2) PCBWay adds a PayPal fee to their price at checkout, and PCBShopper is taking that into account. (Regarding points 1 and 2, in PCBShopper's results for PCBWay there's a note that says "Select the express 24hours build time. Price includes PayPal fee." And 3) PCBWay is showing US dollars and PCBShopper is showing Australian dollars (there's a pull-down control at the top of the PCBShopper price results that lets you switch to US dollars).

At 37:40, Dave says "PCBShopper has failed us". That's an unfortunate choice of words. In fact, PCBShopper has provided the correct results.

- Bob Alexander
  PCBShopper.com
 

This is fair criticism. I wonder if a useful improvement to the website would be to list the best case scenario and the worst case using the data supplied by the PCB manufacturers and courier companies, rather than just assuming the worst.

Then add a "realistic" estimate of board delivery based on historical user feedback.
 

Offline mrpackethead

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #181 on: May 04, 2017, 10:40:24 pm »
theres a couple of Things that break it for me.

(a) Once you become a registered customer of some sites, the pricing changes.  They do reward loyality and over time the discounts get bigger.   I'd not be so happy to pass on my login details to a third party

(b) Minor spec changes when you are pricing can make a big difference to the end price...  You might see that it saves $40 by waiting an extra day..     This all gets hidden.. 

Ultimately the pcbs are actualy so cheap now that i'm much more interested in a reliable consistent thign that i know what i'm getting.
On a quest to find increasingly complicated ways to blink things
 

Offline rea5245

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #182 on: May 04, 2017, 11:14:52 pm »
(a) Once you become a registered customer of some sites, the pricing changes.  They do reward loyality and over time the discounts get bigger.   I'd not be so happy to pass on my login details to a third party

Nor would I ask you to. Nor would it be practical to: imagine PCBShopper asking you for your account information to 25 different manufacturers! No way that would be a good user interface.

If you have a long-term relationship with a company, then you're probably not shopping for the lowest price and you don't need PCBShopper's service (unless you occasionally want to make sure your preferred manufacturer is treating you right).

(b) Minor spec changes when you are pricing can make a big difference to the end price...  You might see that it saves $40 by waiting an extra day..     This all gets hidden.. 

By default, PCBShopper tells you the manufacturers' default manufacturing speed. For most manufacturers, this is the cheapest they offer. PCBShopper only changes that if you specify the number of days you need the boards in. And if you do that, you're basically telling PCBShopper that you're on a tight schedule and time is more important than money.

- Bob Alexander
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Offline rs20

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #183 on: May 05, 2017, 12:15:13 am »
When I was watching the video, I saw that the website showed a total time of 5 to 8 days, and Dave had configured the request to be for a 7-day delivery. I didn't have to read the footnote on the pcbshopper website to know that displaying an option that could take anywhere from 5 to 8 days when you need the board in 7 days is outright lying. To criticize this decision is puzzling to say the least, worst-case time is obviously the most valuable metric if you need the board within x days. But maybe that's just because I'm an engineer and I take the principle of designing for worst case too far.

Then add a "realistic" estimate of board delivery based on historical user feedback.

!!! What do you think the chances are of random people regularly back-calculating and reporting delivery times? What's in it for them? And what are the chances of their numbers being accurate? And how do you factor for Rural vs Urban, Domestic vs Business? This is a wildly impractical idea, predicting actual shipping times is a problem that is not at all specific to pcbshopper, and one that is completely unsolved at that.

Quote
(b) Minor spec changes when you are pricing can make a big difference to the end price...  You might see that it saves $40 by waiting an extra day..     This all gets hidden.. 

"Hidden"? Just try increasing the number of days and see! I'm sure pcbshopper could send out a bunch of extra requests with various parameters relaxed in order to provide such information, but you can see how long it takes to scrape all the websites already. Multiplying that by dozens of config permutations would make the website unusably slow, and we haven't even discussed how to display this information yet.

See, it turns out that it's easier to criticize than it is to create. I feel bad for Bob who has put a lot of effort into producing an undeniably useful website (even if you're of the opinion that you've "grown beyond" pcbshopper, it's obviously tremendously useful to newbies at the very least), and all he seems to be getting back is incorrect criticisms and/or demands for wildly impractical features.
 
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Offline rea5245

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #184 on: May 05, 2017, 12:25:22 am »
Thank you, rs20.

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Offline EEVblog

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #185 on: May 05, 2017, 01:04:23 am »
Maybe Dave could add some annotations in the video, and write something in the description? I know, nobody reads the description :D but at least every new viewer could see the annotation.

Youtube does not allow annotations any more.
 

Offline Macbeth

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #186 on: May 05, 2017, 02:10:10 am »
Quote from: rs20
Then add a "realistic" estimate of board delivery based on historical user feedback.

!!! What do you think the chances are of random people regularly back-calculating and reporting delivery times? What's in it for them? And what are the chances of their numbers being accurate? And how do you factor for Rural vs Urban, Domestic vs Business? This is a wildly impractical idea, predicting actual shipping times is a problem that is not at all specific to pcbshopper, and one that is completely unsolved at that.

Yes, I did originally have a pessimistic "...and that is a whole other kettle of fish" on the user feedback thing but thought better delete that and maybe others could come up with something?

In particular I don't really know how PCBShopper gets paid - is it from referral fees, or adverts? Is there a token left that would allow actual genuine customer feedback vs trolls, etc?

Of course any metric is not a guarantee which is absurd, but all the big boys Amazon, Google, Facebook, e-bay, AliExpress, etc. are making metrics from all your stuff and your upvotes/star ratings/feedback... They seem to be making $billions ...
 

Offline rea5245

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #187 on: May 05, 2017, 02:24:10 am »
In particular I don't really know how PCBShopper gets paid - is it from referral fees, or adverts? Is there a token left that would allow actual genuine customer feedback vs trolls, etc?

PCBShopper gets money from ads and nothing else. I do not get any money from referral fees and I do not get money to add companies to the price comparison list.

There is no way for me to get statistically valid information about delivery times. Imagine what that would require: manufacturers sending me order dates (which I would have no way of validating) and tracking numbers for their shipments (which would be a violation of customers' privacy).

Also, remember that statistics say nothing about an individual. There are two types of people in the world: people who need their boards delivered by a certain date and people who don't. If you need you boards by a certain date, you don't want to hear "there's a 60% chance your boards will arrive when you need them".

- Bob Alexander
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Offline mrpackethead

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #188 on: May 10, 2017, 01:12:03 am »
Just as a side topic.. ( though its a top topic i saw them advertsing ).. just had another box of PCB's and stencils come from Allpcb.com   Quality and turnaround ( and price ) all very good.  I've been using the HQPCB service..  ( allpcb lets you compare between about 25 differnet chinese fabs )..
On a quest to find increasingly complicated ways to blink things
 

Offline T-Reu

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #189 on: August 01, 2017, 11:34:54 am »
I am really sorry if this has been asked before: Are the Arduino code sketch, the schematics and the PDB files up for download somewhere? I am working on a similar Nixie tube project for a SoundCloud play counter. Since I am not a seasoned veteran but an interested newcomer to electronics and programming it would be really helpful for me to be able to look into Dave's Arduino code so I can learn how other people program these things.
 

Offline runeazn

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #190 on: November 17, 2017, 11:13:41 pm »
Hey everyone,

I am trying to build a nixie clock and was watching the series of Dave. But one thing confuses me, I understand that Dave used a hex inverter that supports 3.3v logic as high. However, that would invert the clock signal? Is this then fixed in the software? As I can't find anywhere where it is inverted again in the schematic. Hope this question isn't too stupid.
 

Offline ryemac3

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #191 on: January 20, 2018, 04:42:38 pm »
Dave,

Any way you can post your final sketch for uNixieArduino? I'm trying to use the TPIC6B595 to shift out some data to some nixies and I can't for the life of me figure out how you did it. I tried to replicate what you did during the "Nixie Tube Display ESP8266 Wemos D1 Mini Testing" video, but I must be missing something. For now, I've just breadboarded three chips and have the outputs connected to some LEDs as a proof of concept. However, when I set "subs" to any number, all my LEDs are on. In the video you said you weren't sure if your Binary2BCD function was correct and that you hadn't checked it. So I'm sure the sketch was not final. Did you make any subsequent changes to the sketch after the video was posted? Any help would be greatly appreciated.

Thanks.
 

Offline Rafael

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #192 on: January 20, 2018, 11:23:53 pm »
Hi...

This project will be shared someday? Looks amazing!

Thanks!!
LTZ1000 for voltages, Emmett Lathrop "Doc" Brown for me.
 

Offline szechyjs

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #193 on: January 25, 2018, 05:53:45 pm »
I recently finished my nixie clock project. I used some ZM1000 tubes that I cleaned out of my grandpa's basement. I ended up using the HV5622 HV serial shift register. Even though the datasheet says it requires 10.8-13.2V supply voltage, it worked just fine with a 5V VDD and 3.3V SPI. As I'm a fan of STM32 MCUs I used a STM32F042C6, this provides me with RTC, SPI and USB capabilities. The clock is powered over USB with the use of a HV5W power supply from eBay which provides me with the 170V to power the tubes.

« Last Edit: January 25, 2018, 07:36:08 pm by szechyjs »
 

Offline Rafael

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #194 on: February 22, 2020, 02:37:37 am »
Well, I couldn't find anything like that shared. So, it's time for me to try to fly too. I think it is possible to cascade if the HV power supply has enough current to do so. :)
LTZ1000 for voltages, Emmett Lathrop "Doc" Brown for me.
 

Offline T-Reu

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Re: EEVblog #948 - Nixie Tube Display Project - Part 1
« Reply #195 on: March 06, 2020, 09:55:58 am »
OK folks, after some time I finally finished my nixie tube counter display project. It shows the number of plays I get on SoundCloud. I documented my process from the idea through designing in KiCad up to writing functioning software on my blog.

If you're interested, have a look:
http://mixedtinkerings.com/category/nixie-display/

Greetz and out.

« Last Edit: March 06, 2020, 10:01:17 am by T-Reu »
 


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