It was only recently that James Hartnett came across Nixies -- those tubes for displaying numerals. James loved "that awesome display with the 3D-look and the glow of a tube-like device." When he found one, he instantly decided that he needed to make a clock. He found a Nixie Tube-based Volt Meter. "Volt meter" is a bit misleading -- it's actually a "millivolt meter," said Hartnett. When he decided to turn it into a clock, a Gadget Freak was born -- or created.
The circuit and breakboard.
What the display will look like.
Table 1: Allied Parts List
Allied Part #
Resistor; Carbon Film; Res 1 Ohms; Pwr-Rtg 0.25 W; Tol 5%; Axial; Cer-Core
Note: I did not include a zero-correction resistor in the BOM since it was specific to my meter. You can find a suitable value for your equipment or adjust the zero on the hardware, which will have to be re-adjusted before using it to measure voltages.
Readers might be entertained by a Nixie-tube artwork I made many years ago, using 4 "giant" Nixie tubes--reputed to have come from the NY Stock Exchange when they upgraded. I attach a photo; the piece is about 4 1/2 feet tall. I programmed it to deliver 512, 4-letter words arranged into droll and mildly insulting sentences/paragraphs, all decent. It sold immediately from a gallery, to a realtor who put it in her office for the entertainment of her customers. I wish I still owned it...
This isn't playing with Nixies. Buying Nixies, wiring tube sockets and getting a bite from the high voltage is playing with Nixies.
While interesting that this project outputs an analogue voltage which sometimes represents the correct time, not actually using the Nixie tubes directly kind of takes the fun out of it. You can use any dvm for this and that would be interesting in and of itself.
But what's the point if you don't risk getting a mild shock from playing with the circuit? And if you don't actually use nixies how are you going to learn anything?
Building a display with nixies is not a big deal, just some high volt switching transistors like a mpsa 42 or 92 tied to the output of the driver chip, whether it's a clock or voltmeter or a random number generator.
I've worked with vacuum tubes my entire life and there is a lot more fun to be had lighting them up and making them do something useful or even unnecessarily useful.
You haven't lived unless you've been bitten by 30KV off a color CRT.
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