I'm beginner of electronics. (Please understand that I have used Google Translator.)
I connected the IN-14 Nixie tube to the K155ID1 IC. But the numbers in the Nixie tube do not completely emit. When MPSA42 transistor is used, even the higher current limiting resistor normaly emits light, but now it does not emit light completely even when the resistance of the current limiting resistor's value is lowered. Strangely enough, however, the number 6 was completely luminescent.
6 - fully illuminated 0 - Does not emit light completely 4 - Does not emit light completely And here's the circuit diagram. circuit diagram I connected the cathode of each Nixie tube to each pin of K155ID1, and the BCD input was operated by a switch that connected a 4.7k pullup resistor. The Nixie tube was powered by about 180VDC.
Please tell me how to make the Nixie tube digit flash perfectly.

  • \$\begingroup\$ If you connect one of the cathodes directly to ground does it light up properly? \$\endgroup\$
    – Finbarr
    Nov 22, 2017 at 13:09
  • \$\begingroup\$ yes. all the cathodes work normally. \$\endgroup\$
    – Ho jun
    Nov 22, 2017 at 13:13
  • \$\begingroup\$ Sounds like a duff chip or it's not being connected up properly. Please post a schematic diagram so we can see how it's wired. \$\endgroup\$
    – Finbarr
    Nov 22, 2017 at 13:19
  • \$\begingroup\$ I tested the chip with LEDs, but the chip works well. \$\endgroup\$
    – Ho jun
    Nov 22, 2017 at 13:27
  • \$\begingroup\$ When I removed the pullup resistor and connected the BCD input pin directly to 5V or GND, the number of Nixie tubes shone normally. \$\endgroup\$
    – Ho jun
    Nov 23, 2017 at 7:17

1 Answer 1


Try anode resistor 33 - 18 -15 - 10K k155ID1 internal zener diode 60v, pull-up resistor connected +5v is 15 - 33K.

Kathode (digit ) 'poisoning' - when highter currentt it shine well. Change back to 27 -33K when OK.


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