Nixie Clock Project (Part 4 – A Working Tube)

The new boards arrived early this week! Here’s a side by side comparison of the old board and the new one (notice the difference in the of the white silkscreen around the tubes – the new silkscreen reflects the actual size of the tube, whereas before I think I just plotted down a circle of arbitrary radius).

I finally bit the bullet yesterday and installed one of the tubes on the new board (after installing the decoder and series resistors and testing that out). It was a bit of a process because it turns out that the alignment of the tube itself to the pins is not completely controlled. So when I put all six of the tubes down on the board (with no solder), they were all at slightly different angles!

I may have to come up with a way to combat this if I want to make clocks for everyone in my family, but for now, I settled with bending the pins and aligning it manually. My girlfriend gave me the idea to align the two white dots using a box and my calipers as right angles, as seen below.

After this I tested each digit manually (by driving each pin with the supply and a series 15kΩ resistor), soldered it down, hooked it all up, and wrote a little program to count up (and then go back to zero). I made a little animation to show you!

Now there’s no excuse. It’s time to get everything else soldered down while I wait for the enclosure to arrive!