Building A Decatron Clock
By James Grahame
E. Barbour writes, "Former Philips engineer Ronald Dekker is famous for his website full of unusual construction projects. He now has built a digital clock that uses Dekatron (or decatron) tubes as displays."
They're the forefather of Nixie tubes, which usually contain ten cathodes in the shape of the numbers 0 through 9, and a wire mesh anode. When electricity is passed between one of the cathodes and the anode, the corresponding number shines with an endearing orangey-red glow. In contrast, the decatron is only capable of producing an array of glowing dots.
Dekker decided to build a decatron clock controlled by a modern PIC microcontroller.
He explains, "Surfing the web, the most popular thing to make with a decatron seems to be a spinner. Looking at these spinners I thought it would be a nice idea to make a clock with six (or perhaps even seven) decatrons in a row, with the decatrons showing all kinds of display effects. Instead of simply incrementing the time every new second, it would be great to have a display of forward- and backward-spinning digits, slowly rolling-out to the new time, a little bit like the reels of a slot machine."
The circuit and software is now complete, and the only thing remaining is the case. Dekker has decided to use a mirror mounted at a 45 degree angle to allow reading the digits while the tubes are mounted in a vertical position. The final result should be a unique modern timepiece that brilliantly integrates forgotten technology from the 1950s.