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I am designing a Nixie Tube Clock circuit for some IN12-A nixie tubes. My circuit is a modified version of the one found here http://www.instructables.com/id/SMD-Nixie-Clock/ . You can find my version here: https://easyeda.com/AchilleMerendino/Nixie_Clock-faf484c684294e889f51d773bb96699e . I have made some modifications and I have also included some components that are missing in the original schematic (like the Transistors for driving the HV Shift Register with 12v). Would this circuit work if I get it printed?

The circuit should work like this: The atmega328 should read time and date from DS3231SN and then send data to the HV Shift Register that should in the end drive the IN12A Nixie Tubes

enter image description here

I know about the missing High voltage power supply, I'm still working on it.

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    \$\begingroup\$ No, it won't work. I see two major flaws right off the bat, including your added transistors. Note that we discourage broad, open-ended design review questions here on EE.SE: The answer(s) tend to become long strings of unrelated edits and/or comments. While this might help you with your immediate problems, it is of no value to the site overall. We DO allow design review questions in which you explain your choices and then focus on a few points about which you still have doubts. To get a better feel of what is or is not acceptable, search for "design review" on the meta site. \$\endgroup\$
    – Dave Tweed
    Dec 14 '17 at 15:46
  • \$\begingroup\$ (The other flaw is the lack of a HV supply to the Nixies themselves.) \$\endgroup\$
    – Dave Tweed
    Dec 14 '17 at 15:47
  • \$\begingroup\$ @DaveTweed Thank you very much, I didn't know about the Meta Site, can I repost this question (with more accurate information and questions) there? \$\endgroup\$
    – user171893
    Dec 14 '17 at 15:52
  • \$\begingroup\$ No, the meta site is for discussions about EE.SE policy. Do not post your question there. \$\endgroup\$
    – Dave Tweed
    Dec 14 '17 at 16:04
  • \$\begingroup\$ Not sure why you're bothering to drive the POL line from the MCU. \$\endgroup\$
    – Finbarr
    Dec 14 '17 at 16:06
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I haven't really tried to follow your circuit, but this doesn't make much sense:

You say something about a 12 V interface, but the transistors are used as emitter followers. Not only will that decrease the high level voltage, but it also eliminates the low-going drive. The resulting signals are actively pulled up when the digital signals to the bases are high, but nothing pulls them low when the digital signals are low.

Another obvious problem is:

You haven't even connected power to the tubes!

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  • \$\begingroup\$ Thank you, I know about the missing power supply. Also I did some research and yes, the transistor seem to be useless. But how should I go about driving the ic with 12v then? PS. I did some more research, would a PNP transistor work for this? \$\endgroup\$
    – user171893
    Dec 14 '17 at 16:28