Instructables
Picture of Nixie bargraph clock
2013-12-09 20.57.59-2.jpg

So I have seen lots of Nixie clocks online and thought they looked great, however I didn't want to spend $100+ on a clock that doesn't even include the tubes!

So with a little electronics knowledge I hunted around the various nixie tubes and circuits. I wanted to make something a little different to the large range of generally fairly similar looking nixie clocks. In the end I opted to use Nixie IN-9 bargraph tubes. These are long thin tubes and the height of the glowing plasma depends on the current through the tubes. The tube on the left is in hour increments and the tube on the right is in minutes. They only have two leads and so make building a circuit more straight forward.

In this design, there is an hour and a minute tube, with the heights of the plasma in each tube representing the current time. The time is kept using an Adafruit Trinket microcontroller and real time clock (RTC).

 
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Step 1: Assembling the parts

Picture of Assembling the parts

There are two sections, first the electronics and secondly the mounting and finishing.

The electronic components required are:
Adafruit Trinket 5V - $7.95 (www.adafruit.com/products/1501)
Adafruit RTC - $9 (www.adafruit.com/products/264)
2x Nixie IN-9 bargraph ~ $3 per tube on eBay
1x Nixie 140v power supply ~$12 on eBay
4x 47 uF electrolyte capacitors
4x 3.9 kOhm resistors
2x 1 kOhm potentiometer
2x Transistor MJE340 NPN high voltage ~$1 each
1x LM7805 5v regulator ~$1
1x 2.1mm socket ~$1
1x project box with pcb ~$5
1x 12v DC power supply (I found an old one from some long forgotten gadget)
Solder, hookup wire, etc

Mounting:
I decided to mount the electronics in a small black plastic project box, then mount the tubes on an antique clock movement. To mark the hour and minutes I used copper wire wrapped round the tubes.

Mounting parts:
Antique clock movement - $10 eBay
Copper wire - $3 eBay
Hot glue gun

georgedb7 months ago

Nice! Nixie test circuit is not ok. You need to swap the GND and one of the ends of the resistor (potmeter), now you always use the full resistance.

After changing that, the test circuit worked just fine.

Thereisonlyme (author)  georgedb7 months ago
yes thanks, I was lazy in drawing the fig. I'll redraw it tomorrow! Glad you got it working tho

Thnx. Same problem for the1K trimmers in the Nixie Clock Circuit?

Thereisonlyme (author)  georgedb7 months ago

No, these are wired as variable resistors. So just pin 1 and 2. Pin 3 is left unconnected.

You're absolutely right, now that I look at that schematic again. I must have made a mistake.

zapro7 months ago

According to your schematic, you have the resistor on the emitter-pin on the transistor. this should be avoided, because the threshold of the transistor will float around, with regard to the current running in the IN-9 tube. The resistor should be placed on the Collector-pin instead.

Thereisonlyme (author)  zapro7 months ago
Thanks for your feedback, I'll take this into account on my next project!
spartan3167 months ago

How can I buy this?

Love that antique/modern look! Very nice!

billbillt7 months ago

got my vote

action pig7 months ago

Yeah this is very cool, love the use of the antique movement too!

danamoose7 months ago
Nice work awesome end product
Vorpaxis7 months ago

Nicely done! I've always wanted to do a Nixie build of some kind but they've always appeared so daunting. This seems a bit more approachable and I look forward to messing around on this! Thanks for the instructable