Nixie Clock in a Dome

This is a Nixie clock 3D wired in a glass dome. It is made with IN-12A (ИН-12A) Nixie tubes and an Arduino nano.

This is inspired from a kit I bought a few years ago. I made some modifications to use an Arduino, a DS3231 clock and a DC buck converter module. I also wrote my own program with Arduino IDE.

You will need to be very patient to complete this project. You must be very carefull due to hazardous voltage inside (170 V). And of course you must have a good experience in soldering and understanding electronic schematics.

First, attach the 4 tubes with tape and spacers. The central space between hours and minutes is 10mm. Take care of the correct orientation of tubes.

Align the four driving circuits К155ИД1 upside down ant connect two parallel wires (5V pin 5-GND pin 12) and solder the 68nF capacitors.

Then connect :

• ИН-12A pin 2 ---- К155ИД1 pin 16
• ИН-12A pin 11 ---- К155ИД1 pin 15
• ИН-12A pin 10 ---- К155ИД1 pin 8

Put the circuit back in the right direction and connect :

• ИН-12A pin 3 ---- К155ИД1 pin 2
• ИН-12A pin 4 ---- К155ИД1 pin 1
• ИН-12A pin 9 ---- К155ИД1 pin 9
• ИН-12A pin 8 ---- К155ИД1 pin 13
• ИН-12A pin 7 ---- К155ИД1 pin 14
• ИН-12A pin 6 ---- К155ИД1 pin 11
• ИН-12A pin 5 ---- К155ИД1 pin 10

Drill 4 holes diameter 2mm, approximately 10mm depth corresponding to the diagram.

And below the base, drill recesses approximately 10 mm depth.

Form a u with the brass bar and attach the tubes by soldering pin 12 to the bar.

Add an other bar behind and connect it to the +5V line of the К155ИД1 circuits.

This bar must cross the base because it will be connected under the base.

Connect the DC-DC converter to +5V (bar behind) and GND to the line of the К155ИД1 circuits and through the hole in the base.

Solder the four resistors 22kΩ to pin 1 of the nixie tubes and to +170V of the DC-DC converter.

Fasten the 7805 to the heatsink and solder the two capacitors and three insulated wires.

Then fasten the heatsink to the base.

Make the connections below the base between DC plug, the 7805, the +5V bar and GND.

Connect the two 74HC595 to +5V, GND and the К155ИД1 according to the diagram.

After unsoldering the Grove connector on the Arduino, it is easy to wire it to the clock placed below.

Then connect the Arduino Nano to +5V and GND and solder the IR reciever.

The last thing to do is to connect the data lines of the Arduino Nano to the 74HC595 and the 470Ω resistor.

Then you can download the program on the Arduino and adjust the time.