Larry's Projects

Nixie Tubes Plus:

Dekartons and Magic Eye Tubes



Nixie tube clock

      Here is my new Four Nixie Clock. This one is built with B5441 (Burroughs) Nixie Tubes. I came up with a different case design based on laminating 10 layers of cedar and pine. The blue lighted layer is clear acrylic.
      Nixie (Numerical Indicator Experiment #1) was the name given these little beauties. They were first marketed in the early 50s, and were, I suppose, the first modern digital displays. This is my first work with nixie tubes and my first nixie clock. I was famaliar with vacuum tubes but had never encountered nixies until I testflight crewed on a recon aircraft, in 1960, where I was assigned to work. The fascinating 3D effect of the numbers, flashing out their navigational data, caught my eye and stays with me even now in this 21st century.
     I came upon several of these among some old TV tubes and finally found my chance to build something with them. Found some circuits online and there I was, hooked.

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Four Tube Nixie Clock


      My Four Tube Nixie Clock came about mostly because I happened to have most of the parts on hand. That is, except those for the new 170 Volt power supply. The power supply is built from several images found on the internet but the one I paid most attention to is that by M. Moorrees at I started with the NK01B kit, then built my own from scratch.
    The clock circuit is bacically the same as my six tube Nixie clock, however, with two CD4017s used to divide the 1 Hz time down to 1/60Hz. Also, I used SN75468 ICs for the nixie drivers instead of the 69s, the difference being, the 68s match the 5 volt circuit supply that I used.
    For a slightly more interesting effect, I installed blue LEDs in the nixie sockets so they would shine through the glass of the NL-8422s. And, a dimmer circuit for the nixies.
    The enclosure for my Four Tube Nixie Clock is made from a framework of pine with a covering of oak veneer, and carved wood legs.


The Nixie Barn


the "Nixie Barn"

      My facination with the nixies only grew as I soon found myself looking at Dekatrons and Magic-eye tubes. Here I'm using a GC10B dekatron in a circuit kit from The kit is called the 6 Nixie clock with Dekatron. However, I have made only one modification. I'm using 4 nixies, the Burroughs B-5991. This is what I had on hand and they fit my layout, the Nixie Barn.
The circuit board has quite a large number of parts but assembly was straight forward and it all worked as described.

Another Threeneuron's Pile o'Poo project

The The Tube Dekatron Spinner


Tube Dekatron Spinner

      Here is a rather novel project using vacuum tubes and a dekatron (decade counting) tube. It will not tell the time of day or show a pendulum swinging at once per second, but is intriguing to watch. It was fun to build using tubes (instead of IC components) to drive the dekatron.
       The circuit is from In building this circuit into a display/demonstration project, I added a reverse switch and a range selector. Also, a couple of orange LEDs under the tubes just to brighten them up a little.

Another Threeneuron's circuit

The The Magic Eye Winker


Magic Eye Winker


The vintage vacuum (or gas filled) tubes just keep on coming. The electron ray indicator tube even predates the nixie. Here I am using a 6DA5 (EM81) in the circuit I found on the threeneuronswordpress website. The plastic case is made from a CD box.

My First Nixie Clock

nix<h4 6 Tube Nixie Clock

      My circuit is adapted from plans drawn up by Peter Wendt from his website My Nixie Clock Project. The schematics and explanations are there. I have provided a schematic of my 1Hz timer as it is different from the one shown on Wendt's web page.
      The parts I used are from Jameco Electronics, Mouser and my own collection of spares. The ZM1000 nixie tubes came from my own parts and Sphere Research's nixie stock.


Here is a Digital Barometer

and a Digital Thermometer



       My barometer is built with a MPX2200 pressure sensor, a LM324 quad op-amp and a CX101BG LCD digital display. The MPX2200 measures pressures in the uVolt range. The op-amp circuits (LM324) multiply this voltage, providing about 1 volt/100KPa (1000 millibars) for the display. With the display wired to measure 2V FS, the 100KPa or 1000 millibar barometric pressure will read as 1 volt on the CX101BG. The case is oak veneer over a pine frame.



       My basic digital Thermometer is much less complex than the Barometer. The temperature sensor is a LM34. For my purpose the LM34 reads in degrees fahrenheit. Its output is 10mV/ 0F so the sensor will output 700mV at 70 degrees reading on the display The 78L05 regulator provides the 5 volt supply for the LM34 and the CX101BG digital display. A trim pot is included for fine adjustment of the temperature. The thermometer case is built with redwood.

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