Nixie Tube project..... some questions.

Hey Gang-

I have messed around with all sorts of Arduino based projects before.. but I have yet (and always wanted) to mess with any Nixie Tube based projects...

I am starting to plan my first one now.. and have some questions.

Basically the power supply (booster/step-up) and the driver that is most recommended are the focus here.

POWER SUPPLY:

I'd like it to be small in size.. and of course the most affordable.. LOL.. (ie: CHEAP!)

I found these: http://www.ebay.com/itm/Launch-SALE-Limited-Time-NCH8200HV-High-Voltage-DC-Power-Supply-for-Nixie-Tubes-/172818490547?epid=2175702943&hash=item283cc8e4b3:g:MosAAOSweyNZj516

http://www.ebay.com/itm/DC-5V-12V-to-170V-DC-High-Voltage-NIXIE-Power-Supply-Module-PSU-NIXIE-TUBE-ERA-/322511957768?hash=item4b1735ef08:g:q8AAAOSwCotZmjps

http://www.ebay.com/itm/High-Voltage-Power-Supply-incl-5V-and-3-3V-for-Nixie-Magic-eye-tubes-old-radio-/263149056981?epid=571422867&hash=item3d44e7f3d5:g:EjMAAOSwGJlZHqTX

  • I'm not exactly sure how I'll be powering this.. but I'm thinking either USB, 5v wallwart or some type of Li-Ion 18650 battery pack (3.7v) or something..

the above say they work with as little as 2.5v input.

DRIVER CHIPS:

I know there are a couple of driver/chips people use to drive their nixie projects... but I'm not experienced enough to know if there is a better option or which is preferred over another (or why)...

I'm also not clear as to what ELSE (ie: components) are required to go along with a driver chip.

I found these:

SB74141N http://www.ebay.co.uk/itm/SN74141N-TEXAS-INTEGRATED-CIRCUIT-16-PIN-DIL-NIXIE-DRIVER-NEW-1-PIECE-/262979859679?hash=item3d3ad234df:g:ShoAAOSwlY1ZFG23

K155ID1 http://www.ebay.com/itm/2x-Nixie-Indicator-Driver-IC-Chip-K155ID1-KM155ID1-7441-74141-NOS-/311484790881?var=&hash=item4885f0b861:m:mjehU_rEb29c0ehDzxPbslA

So I'm looking for a little guidance here.. as well as any insight from those who have been down this road before..

Tips.. Tricks.. Things to be aware of....etc..

In the end.. I'll be trying to find the smallest Nixies available.. (to keep the overall project small in size/footprint)

Thanks in advance.

I’m also not clear as to what ELSE (ie: components) are required to go along with a driver chip.

There are plenty of examples of complete Nixie tube projects on the web, with schematic diagrams showing all the additional parts and connections. Start with those.

I made a small 4 digit ESP8266 based NTP nixie clock earlier this year using IN12B tubes.
I use a 5v 700mA nokia phone adapter to power it. The power supply is 2 stage. Stage 1 is 1$ max 24 volt boost converter which is the size of a small postage stamp. I run this at 12 volts. The second stage is built to a standard boost converter design based on a 555 timer circuit which provides up to well over 300 volts, nearly twice what you need.
I use a single Russian driver chip k155id1 and an MCP23016 port expander expander to multiplex the tubes.
I intended to publish all the details after tidying up the software but, somehow, that never happened.
I can, however, certainly provide further details as required. It may even motivate to me to provide a complete design document.

Nixie-IN12B.jpg

@jremington

umm.. thanks for the reply I guess. That being said.. I have looked at some tutorials.. and will also continue to do so..

but it doesnt replace good old fashioned 'communication'.. and chit-chat form other makers/developers who have been down this route.

Nor does a tutorial talk about the chips, differences or why one would/could/should be used over another.

@6v6gt

thanks!

nice project! I'm trying to stay away from a 12v source.. and keep it either:

3.7v Li-ion battery or a 5v (either from USB or 5v walwart)

Is that a problem?

*Sorry, I'm not full grasping the two stage power supply stuff/comments?

One of the power supplie/booster boards I looked at had:

HV output 5v output & 3.3v ouput

In my mind..

I would be powering the nixies with the HV..

the Arduino and my other board (TEA5767 FM module) with the 5v output.. (not sure on the current it gives though)..

Can you recommend one of the links provided? (and maybe a reason why you think its the best/better?) (just trying to learn here!) :)

And a why you chose the k155id1 chip vs the 74141 chips?

If I didnt go the port expander route.. I would need 1 chip for every 'tube' in the project.... correct?

Side question:

What does the ESP8255 module do for your project? (or is it just being used to get the current/internet time?)

My project is basically a simple FM radio.. but I want to use nixies to show the 'station'..

  • which reminds me.. I need to look into some sort of 360/continuous POT or component for scanning through channels. ( was going to use up/down momentary buttons.. but I think that would be kill the usability!)

OK. I assumed a clock project but you simply want to display the frequency or something similar maybe to 1 decimal place eg 105.6 (MHz).
Is that it ?

I also wanted to use a 5 volt power supply, and since most nixie power supplies required a minimum of 9 volts, I made a 2 stage power supply. The first providing 12 volts from the 5 volt source. The second using the 12 volts and providing the minimum of 170 volts to drive the tubes. It is difficult to go directly from 5 volts to 170 directly mainly because a logic level mosfet is not robust enough at high voltages. It does look, however, that 2 of your links are for products which appear to accepts input voltages of 5 or lower. I guess between those two, it is simply a matter of price.

The choice of driver chips was governed by what the seller of the nixies supplied. I just used those (k155id1 ). These don’t latch. If you don’t want to use multiplexing you’d need 4 of these and 16 spare arduino pins (or maybe 14 pins if the first digit is displaying only a 0 or 1 ). If you don’t have the required number of free pins, then you have to look at port expanders, shift registers etc.

I used an ESP8266 because, as you guessed, the clock gets its time from the internet.

The TEA5767 needs an amplifier. How many (audio) watts do you require ? This may have an impact on the power supply you choose.
I did build a radio based on this chip but it never got past the bread board stage. It does have a channel scanning function so you could get away with just 2 buttons. However, depending on the module and the crystal used, the channel scan function may not be so good. The data sheet warns of this because of a possible mismatch between the channel frequencies and the scan steps. I guess from the usability, it also depends on how many FM stations you get in your area.

@6v6gt

Awesome feedback! (thanks!)

You are correct... some regular old FM stations/frequencies..

I'm not sure of the range exactly.. but roughly

and.. dang it!..

To be clear.. I have this TEA5767 module.. (more of a breakout than just the pure module itself)

http://www.ebay.com/itm/TEA5767-FM-Stereo-Radio-Module-for-Arduino-76-108MHZ-With-Free-Cable-Antenna-/310795359575?epid=622053440&hash=item485cd8d557:g:u08AAOSwcUBYVKTm

however.... I didnt even realize I would still need an AMP for this!! (do headphones require an amp? or is it built in?)

I suppose I can try to add one to the mix!...

Question on the nixie power supplies I posted above..

you mention most need 9v.. I saw some that said it needed 12v.. but the ones I posted above have a variable INPUT voltage requirement.. from like 2.5v to (whatever)...

Am I understanding that IN-correctly, that I can NOT give 2.5v to it and have it output an HV stream? (if I am understanding that wrong.. then what is the 2.5v-xxx rating even for then?) I -think- you re-asured/confirmed this above (that some of those products will work @ 5v or under...etc)

*in my mind.. I was going to use either headphones.. (which I thought would 'just work'.... or some powered external speakers.. which would work.. as they have their own amp I'm guessing)

In that case it is OK. That radio module you have shown does include an 80mW headphones amplifier (TDA1308).

The power supply that had an input voltage down to 2.5 volts also has a picture with a caption "2.5volts can drive a [single] glow tube" so the power output is dependent on the input voltage. But at 5 volts it appears to be able to power 12 tubes so that should be OK. It looks like the wound component on the circuit board is not a simple inductor but probably (also) a transformer but anyway an interesting design.

You have to be VERY VERY careful in circuit design, PCB layout and shieilding if you’re trying to receive low level FM radio signals with computer chips nearby - eg an arduino output has rise/fall times of < 5nS, giving harmonics up to 200MHz or more.

I’ve designed a couple of famous name HiFi FM receivers in my time, and found this to be a serious problem.

Metal cans, lots of ferrites on power and signal lines, carefully seperated earth planes etc are required.

Allan

ps 6V6GT - I remember 6V6’s, and their bigger relation - the 6L6. Being a Brit the EL84, 34 and KT66 and 88 were more my field… and ( being a RF guy ) the QQV03-10 , QQV06-40A series etc.

Ah - the old days!

Switching mode power supplies can be very (electrically) noisy. I have even problems with clock I built which uses a 77kHz radio receiver to get a time signal (dcf77 Frankfurt) when it is powered by some cheap buck type chargers intended for mobile phones etc. It is the same with the boost converter type power supplies in mobile "power banks".

But I guess the OP will have a fun learning project in the world of vintage electronics. You can still get many components from suppliers in Russia. When I built my first valve amplifier (6V6) as a schoolboy about 50 years ago, I got all the bits from shops on a trip to London's Edgeware Road.

If you want to build a retro-shape radio, you can use some old tube-based radio for the case, speaker and transformer. In the best case the transformer will have a couple of primary taps, which allow to adjust the secondary anode voltage into a useful range. Nowadays step-up converters mostly have a limited step-up ratio, so that it may be necessary to convert the battery voltage in two steps.

The Nixie voltage must reach at least the ignition voltage of the Nixies (>= 190V), but it must not be too high, else you risk to kill the (74141…) drivers, or it will be impossible to turn the digits off again. Typically one of the digits is burning all the time, with a voltage drop of about 140V, and the remaining voltage on the anode resistor. The choice of the anode resistors will control the anode current and thus the brightness of the digits.

For turning a digit off again, the driver output must drop enough voltage from the supply voltage, so that the remaining (tube) voltage drops below the minimal burning voltage. Unfortunately the 74141 supports a maximum “off” voltage of about 60V only, so that the supply voltage must not exceed that voltage plus the minimum burning voltage. If another digit shall be on at the same time, it will limit the common anode voltage to its ignition voltage, so that the other driver outputs operate in the safe area. So it’s safe to have one digit of every tube “on” all the time, only leading zero suppression or random values at boot time deserve more care.

When I built my first calculator, back in Germanium age, none of the available transistors supported enough voltage to turn the digits off, so that I used relays to drive the Nixie tubes. Unfortunately I forgot (didn’t know about) the clamping diodes over the relay coils, so that every switching relay scrambled the contents of the calculator registers, and the whole thing was only rattling all the time . Nowadays the voltage converters may cause similar problems, but I wish you all the best with your project :slight_smile: