If you’re like [Richard], you’ve got a few really rare components lying around. Maybe it’s a very weird micro or a really tiny CRT, but eventually you’ve got to build something with these parts. When [Richard] decided to put some ITS1A neon display tubes to use, he fell back to the old standby – a really awesome clock.
Unlike the lowly Nixie tube, the ITS1A tube is weird. It’s a neon seven-segment display that can be controlled directly from the pins of a microcontroller. It does this with the help of seven tiny thyratrons in each segment. Even though this tube has neon, the display isn’t the familiar neon orange-red. The tube emits a lovely green with the help of a phosphor coating.
With a single digit already incorporated into [Richard]‘s clock, he needed four indicators for the hours and minutes. After a failed experiment with a crazy 4-color, 16-pixel Melz ITM2-M display, he moved on to a simpler MTX90 thyratron indicator.
Using the same control scheme as his earlier numitron clock, Richard had a PCB made and wired everything up. The seven-segment tube indicates the value, and the indicator tubes indicates the position of the digit in the XX:XX standard. A very cool build with parts you don’t see coming around often.