Wanting to build a Nixie Calculator

About the construction: I am envisaging a fair sized wooden case, say in walnut, oak, or mahogany, all nicely varnished to give an antique retro look. It would not be hard or expensive to construct either.

spec

nzoomed said:

Yes your right about that, could find another indicator tube to use or else just program an arduino to do it without the -

Click to expand...

You could even use a small single tube with a color to match the Nixies for the negative sign.

spec

Look here **broken link removed** under "New graphic display for 8050".

I think one issue with multiplexing Nixies is the turn on time for the gas to ignite (lack of a better word). Always had issues getting a plasma in a sputtering system (RF or DC energy and typical argon atmosphere), it's a combination of pressures etc, but it was never instantaneous. Argon is blue BTW.

I doubt you can pull off the "steady state" type of voltage that will keep a plasma pixel on or off. You raise and low above and below another threshold to turn the pixel on or off. This is how plasma displays work.

Your probably better of demultiplexing and latching.

Here's http://groups.google.com/forum/#!topic/neonixie-l/gqA6OpDbdXM a discussion about the advantages/disadvantages of multiplexing nixies.

KeepItSimpleStupid said:

Look here **broken link removed** under "New graphic display for 8050".

I think one issue with multiplexing Nixies is the turn on time for the gas to ignite (lack of a better word). Always had issues getting a plasma in a sputtering system (RF or DC energy and typical argon atmosphere), it's a combination of pressures etc, but it was never instantaneous. Argon is blue BTW.

I doubt you can pull off the "steady state" type of voltage that will keep a plasma pixel on or off. You raise and low above and below another threshold to turn the pixel on or off. This is how plasma displays work.

Your probably better of demultiplexing and latching.

Here's http://groups.google.com/forum/#!topic/neonixie-l/gqA6OpDbdXM a discussion about the advantages/disadvantages of multiplexing nixies.

Click to expand...

Hmm, interesting stuff.

About multiplexing Nixies: I vaguely remember a technique where you can keep the Nixies alive with a very low current, not sufficient to make them glow, so that they respond faster.

It would certainly be better to drive the Nixies direct, non multiplexed, but it would involve a load of hardware and wiring.

spec

spec said:

Hmm, interesting stuff.

About multiplexing Nixies: I vaguely remember a technique where you can keep the Nixies alive with a very low current, not sufficient to make them glow, so that they respond faster.

It would certainly be better to drive the Nixies direct, non multiplexed, but it would involve a load of hardware and wiring.

spec

Click to expand...

Maybe not as bad as you think. You can start out Multiplexed and then latch/decode/drive.

So, for example you had a seven segment mux, Decode early (seven segment to BCD) to BCD, then latch/decode/drive at the tube.

KeepItSimpleStupid said:

Maybe not as bad as you think. You can start out Multiplexed and then latch/decode/drive.

So, for example you had a seven segment mux, Decode early (seven segment to BCD) to BCD, then latch/decode/drive at the tube.

Click to expand...

Of course, just one latch per Nixie.

spec

I don't see multiplexing as an issue. Yes there is a finite time for the gas to ionize, but there is also a finite time for the gas to deionize. Neon lamps are powered from 50/60 Hz all the time and they don't complain. And in that situation the polarity is alternating. However, you can also power them from halfwave rectified AC without any problem. For multiplexing Nixies, I'd want to keep the multiplex frequency reasonably high in order to prevent flicker. However, if I were starting from scratch, I'd use a PIC for the processor and one of the HV serial shift registers that I mentioned earlier so that no multiplexing would be necessary.

In a previous Nixie project, I used an Allegro A6818 high voltage shift register (now obsolete unfortunately) which has 32 outputs. So, one chip was enough to drive a complete 3 1/2 digit display. Plus, they could be daisy chained for 3 more digits per chip. Hence only two PIC output lines required for any number of digits.

Edit: see attached thumbnail for typical implementation of a PIC driving HV shift register drivers.

spec said:

About the construction: I am envisaging a fair sized wooden case, say in walnut, oak, or mahogany, all nicely varnished to give an antique retro look. It would not be hard or expensive to construct either.

spec

Click to expand...

I was thinking something steampunk perhaps, or else an industrial look, perhaps something that looked like a vintage calculator of the period.

Comment: What the woodworker said to the engineer.

This is what my last Nixie project looked like. 20mm thick MDF with dark brown stain to make it look sort of like bakelite.

Would have looked better if I'd remembered to wipe the dust off before I took the picture.

The base was hollowed out to fit the electronics.


This is the 3 1/2 digit display using the A6818 driver that I mentioned previously.

This guy tried funding this one as a kickstarter project.
https://www.smbaker.com/nixie-tube-calculator-powered-by-a-raspberry-pi
Seems a bit of an overkill to use a raspberry pi though.

I built a nixie clock a couple of years ago. I used a pic to make the power supply. If you're interested see https://www.electro-tech-online.com/threads/pic-driven-nixie-power-supply.142537/

Mike.

Pommie said:

I built a nixie clock a couple of years ago. I used a pic to make the power supply. If you're interested see https://www.electro-tech-online.com/threads/pic-driven-nixie-power-supply.142537/

Mike.

Click to expand...

Thanks, looks good!
I will keep this in mind for future projects.