Electronics My nixie clock

[MisterX]

About a year ago I found this nixie clock gallery http://www.electricstuff.co.uk/nixiegallery.html . Having looked at this, I decided to build mine clock also. Here are the results:

Front view:




On the front panel you can see the switches for setting the hours, minutes, fast/slow set, seconds reset and common reset (makes all the digits 0).

Rear view:


There is a power switch and a fuse holder there.

Close-up view of the front:


Peter Wendt's design consisting of 32768 crystal generator, 4017 decade counters, and 45 MPSA42 NPN transistors, was used (see the details here: http://www.mcamafia.de/nixie/ncp_en/ncp.htm. The power supply produces 8VDC for the ICs, 300VDC for the nixies and 120VAC for the small neon lamps used as the colon separators. Burroughs 6844A nixies and some Soviet neon lamps are installed. The case is made of finished red oak. Two white plexi plates for used as the front and back panels.

[coorz]

Nice work! i love them nixies, so retro

[Turbokeu]

Welcome to the world of nixies!
Nice job!

Why do you use +300VDC for the nixies? (180-200V is more than sufficient)

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[Rd52]

srry to be stupid, but whats a nixie?

[Murdoc]

Goto the second link that 'MisterX' gave. I have been tempted to make a Nixie clock but I think I would just go straight for a microcontroller.

I'm also considering using Nixies' for my final year project at uni in a 'digital Q meter' to keep something a bit retro, and they look damn cool!

'doc

[Rd52]

ohhhh i get it now, wow thats cool i hadnt seen anything like it before

[MisterX]

Turbokeu: it's 300V because of the 12V - 240V transformer plus the rectified AC. Of course, the anode resistors lower that voltage. Probably, the DC-DC converter might serve better for powering nixies.

Rd52: Nixie is a gas-discharge tube, 1 anode made of mesh, and 10 cathodes in the shape of digits. When >170V are applied between the anode and one of the cathodes, the certain digit starts to glow. Follow the links in my first post for further info.

The only problem with the nixies is that it's unclear how long they might serve. The datasheets state the figures like 5000-20000 hours, but I heard and read that they work much longer.

[OtakuHawk]

the beautifull thing about nixies and other vacuum tubes is they are highly radiation hardened. so even after WWIII at least you'll know what time it is.

[Turbokeu]

Originally Posted by MisterX

Turbokeu: it's 300V because of the 12V - 240V transformer plus the rectified AC. Of course, the anode resistors lower that voltage. Probably, the DC-DC converter might serve better for powering nixies.

This a very simple and approved SMPS nixie PSU schematic based on a 555 timer. The principle is used in lots of nixie schematics.
I use it to test my new acquired nixie tubes.

The only problem with the nixies is that it's unclear how long they might serve. The datasheets state the figures like 5000-20000 hours, but I heard and read that they work much longer.

When multiplexed nixies even last longer, I know of guys on Neonixie-L forum that have clocks running already for 6-7 years, 24/24H a day.
Mercury addition in the tube extents their life span to 2-3 times. Most last generation tubes do have mercury (often visible as a blue haze around the orange numerals when lit).

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[MisterX]

Turbokeu: thanks for the circuit schematics. I might also try the voltage doubler/tripler circuit (capacitor+diode).
Mine nixies probably don't have the mercury addition, since the glow color is pure orange. I heard that those 6844A are the first generation nixie.

[OtakuHawk]

cap/diode doublers work well enough. I get about 320VDC from a 119Vrms (main) source.

just be sure to have some decent sized caps to push enough current if you're using a lot of nixies.

[BioSniper]

I have no idea about electronics ( I wish I did ) but that looks ace.
Wish I had the knowledge/understanding to actually make one of these things

[Turbokeu]

Originally Posted by BioSniper

I have no idea about electronics ( I wish I did ) but that looks ace.
Wish I had the knowledge/understanding to actually make one of these things

There are some very good nixie clock kits available.
The ones I know best are the kits from Claus Urbach.
I bought and soldered already six of those kits.
All you need is some solder skills to populate and mount the two PCB's.
The kits contain the two PCB's and all needed parts, except for the nixie tubes and the 12V wall wart.
The wall wart is easily available from local stores, the nixie tubes from eBay for example.

The kits come in three versions:
- 1.08a for smaller nixie tubes (see Claus's website for compatible 12 to 18mm digit size tubes).
You can find a set of six (Russian) IN-14, IN-16 or IN-8-2 tubes for as low as 15 Euro.
- 1.08b for the big and expensive Russian IN-18 nixie tubes (40mm digit size).
These two kits come with the same clock board but different tube board.
A set of six IN-18's will cost you 120-140 Euro.

- One board 1.06 kit for Z566M/ZM1040 tubes (30mm digit size).
Those tubes become quite rare and expensive (about 100-120 Euro for a set of six)

The advantage of the 1.08 kits is that there are magnificent ready-made K7 and K8 aluminum housings available from Mike Mayberry from Klokworks.

1.08a kit with Klok K8 housing and Russian IN-8-2 tubes (18mm):

1.08a kit with Klok K8 housing and Japanese NEC CD66a tubes (16mm):

1.08b kit with Klok K7 housing and Russian IN-18 tubes (40mm):


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[OtakuHawk]

you can get tubes pretty cheap on ebay if you bide your time and wait for a deal.

[gideon]

I really love nixie tubes only thing that holds me from making one is that im VERY broke and the tubes are so small and the bigger ones VERY expensive

[MisterX]

Well, the NL-840 types are pretty inexpensive, and the digits there have a height of 15 mm. You can also use the VFD tubes, which are slightly cheaper than the nixies themselves.

[Turbokeu]

Originally Posted by MisterX

Well, the NL-840 types are pretty inexpensive, and the digits there have a height of 15 mm. You can also use the VFD tubes, which are slightly cheaper than the nixies themselves.

Yes, VFD tubes (Russian IV-4, IV-6, IV-8, IV-11, IV-12, IV-17, IV-22) are cheaper to buy than nixies.
But VFD's require two power supplies: AC Filament current/voltage and DC anode/grid voltage.
AFAIK there are no VFD clock kits available, even no complete VFD clock schematics, that's why I'm busy developing them myself .

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