This remake of the November 2014 Precise Nixie Clock from Elektor now also displays seconds on two nixie tubes. The addition did require a microcontroller update since the original PIC18F2480 didn’t provide enough I/O-pins for two extra digits: the clock is now controlled by a PIC18F4420. A tiny neon bulb was added as separator between minutes and seconds digits. The old design used Russian IN-14 nixies, now as good as out of stock. The new version has IN-12 nixies, pin compatible with other oval shaped nixie tubes like the ZM1100 and CD56. Since these are top view nixies, we made a separate PCB for the display that can be mounted perpendicular to another PCB containing the rest of the hardware. Six 10-way (box) headers (spaced on a 100mil grid) are used for the connection between the two boards.
If you wish to use other tubes, it is easy to assemble your own display on Veroboard. A full description will be published in the May & June 2016 issue of Elektor Magazine.
* Polymethyl methacrylate (PMMA), aka Plexiglas, Acrylite, Lucite, or Perspex