Tweet :: Nixie Tube Kitchen Timer


What's this?

This is a kitchen timer with nixie tubes as its display.

Why nixie tubes? Why a kitchen timer?

I accidentally got hold of nixie tubes in 2015, and decided to make something with them.

Nixie clocks are favorite of everybody, but I thought just watching numbers is boring (well, it's not really). I wanted something that I can punch numbers into nixies.

At first I thought of a calculator but that seemed too much. Then I remembered that my cheap old kitchen timer was failing, so I chose kitchen timer as my project. It was also because I didn't see any timer project made with nixies (I had seen dekatron ones).

What does it do?

Timer, stopwatch, and clock.

You can have it standing on a table, or you can hang it on a wall as it has a hang hole on its back.

Is it really kitchen compatible?

I designed the timer so that you can touch it safely with your hands wet.

Its enclosure is made from PMMA (plexiglas) and PVC, which covers nixie tubes and its PCB. This protects nixie tubes and the PCB from little amount of water splash from top and front. I also chose a membrane keypad, which is waterproof, as its input device.

Its bottom part and hang hole on the back are not protected, so water from bottom or back can do some damage. However, I assume those events are rare if you keep the timer away from kitchen sink. Moreover, if you hang the timer on a wall, I guess it is practically trouble-free.

As a matter of fact, I have been using it everyday in my kitchen since December 2015, with nixie tubes turned on all the time, without any failure (as of April 2016). It is hung from a magnet hook on my fridge.

How good is it? Is it really useful?

Punching numbers into nixies is fun, just as I first intended.

Well, not only that. The nixie tube timer is in fact much more convenient to use than I expected.

As soon as I started using my nixie tube timer in my kitchen, I realized that nixie tubes are far more legible than now-more-common 7-segment displays. This helps me a lot while I'm cooking multiple dishes in parallel and I need to check the remaining time in just a glance.

Detailed specs?

Tube TypeB-5991(8422)IN-12
Power5V 0.2A (via Micro USB)
Dimensions (world)110mm(W) × 42mm(D) × 135mm(H) (without protrusions)
Dimensions (U.S.)4.3"(W) × 1.7"(D) × 5.3"(H) (without protrusions)
Digit Height15.5mm (0.6")18mm (0.7")
WeightAbout 200g (0.44 lbs) (without cable)
Timer Durationup to 99 mins 99 secs (100 mins 39 secs)
Stopwatch Durationup to 99 mins 59 secs
Clock24-hour with battery backup (CR-1220)
Alarm Sounds4
Power SavingSleep on Idle
Enclosure MaterialPMMA, PVC
Photos from 3 Sides

That keypad looks awful, it is ruining nixies! / I love to see that keypad with nixies!

Very interestingly, I receive both of these two opposing feedbacks. I hear the former a bit more than the latter, however. I do understand both feedbacks. In fact it was the toughest design choice I had to make.

Basically, I designed the timer to be very up-to-date. 0603 SMD resistors and MLCCs, TQFP and TSSOP chips, SOT23 transistors, a Micro-USB connector and an FTDI chip. PCBs with soldermask, lasercut Plexiglas and plastic screws. None of them were around when nixie tubes were commonplace. Membrane keypad is just one of them. This timer is fascinating because only nixies are retro among all these up-to-date components. Those who say they like the keypad get this point.

At the same time, on the other hand, I agree with those who say the keypad is ugly. I designed the timer with no intention to make it an aesthetical masterpiece, but I also feel that the keypad doesn't suit nixie tubes very well. I wished (and still wish) I could at least get some other (good) membrane keypad that suits nixies better. The keypad I used is the only well-constructed one I have obtained so far.

As a solution other than membrane keypads, I could have used mechanical switches for keypad, for a better appearance of the timer. But that will compromise its kitchen compatibility because they are not waterproof. This “good looking vs kitchen compatibility” was a tough call. I actually thought about ditching waterproof several times while designing the timer, but after all, I wanted a practical kitchen timer in the first place.

(I know there are waterproof (e.g. IP65) keypads, but did you know that those cost way more than nixie tubes and other components altogether?)

How did you make it?

All designs were done with KiCad EDA, including Plexiglas cut outlines.

PCBs and lasercut Plexiglas are from Elecrow. For the first lot of timers I soldered and assembled them by myself.

The first 4 timers were for sale at the Comic Market in winter 2015, and they received unexpectedly good responses from attendees there, which lead me to build more timers.

For the second lot, I ordered PCBs as assemblies from Elecrow so that I didn't have to do all the soldering. Final step of assembly, which includes soldering tube sockets and covering it with a PVC strip, is still done by my hands.

Information at neonixie-l google group helped designing nixie circuitry very much.

Do you sell it?

A couple of lots were sold in 2015-2016. It is no longer on sale, and there's no plan to re-sale it, because of several difficulties around nixie stuff these days.

Is there any technical documents I can refer to build my own?

Yes, please see this page.

Who made it?

Kouichi Kuroi (

I have questions/comments to you. How can I reach you?

Twitter is best. I'm usually tweeting in Japanese, but you are welcome to mention me in English.

Alternatively, my e-mail address is on home page.

Media Reactions


More Pictures

Close-up shot of the Nixie Tube Kitchen Timer (second lot).

Booth signboard at the comic market (click to enlarge).