HSD5 Nixie tube display

Project

Calibration display for NASA

Brief

April 4, 2019. I received a brief email: "Hello, We are looking for a clock that can take an IRIG input. (Inter-Range Instrumentation Group time code.) Specifically, we use IRIG-B123 here and we need a display we can photograph with high-speed cameras to verify their timing accuracy. Decades ago, we photographed Nixie tube displays that showed the timing done to 1/1000th of a second and was wondering if that is possible today with your nixie tubes. Thanks."

In colaboration with

NASA

This was the first time someone asked us to build a project with nixie tubes not because of their appearance, but for the way how they work. Even more exciting was the fact that the email came from NASA!

Calibration display
Calibration display

We got together specifications for the display and started the work. The first task was to find out the maximum frequency the nixie tube can reliably switch between digits. It turned out we can go up to 100 000 changes per second, so it would be possible to calibrate 100 000 fps cameras.

Nixie tube on a high speed camera
Nixie tube on a high speed camera

Within several months, we implemented the IRIG-B 123 interface and designed the electronics. The most important person behind the electronic design was Sebastian Melzer who worked for us as an electronic engineer by then. We had to make sure the clock will identify the beginning of each new second on the IRIG signal with accuracy around 1μS. Then there was propagation delay of the individual ICs, software etc..

Prototype
Prototype

After 6 months of work, we had the display finished and shipped to the customer to Kennedy’s Space Center.

Electronics finished
Electronics finished

Dalibor, we are actively using the second clock, along with the first. It has made our testing so much easier than before.

The customer
Display finished
Display finished
HSD5 Nixie tube display
HSD5 Nixie tube display
Uncertainty meter
Uncertainty meter