Problem with K155ID1 Nixie Driver

Discussion in 'The Projects Forum' started by elko739, Oct 25, 2015.

  1. elko739

    Thread Starter New Member

    Oct 25, 2015
    Hy guys !

    I have recently started a nixie clock project and now im trying around with the drivers. I have got some original K155ID1 Drivers (used) and I now have problems with them. According to the truth table ( to get Pin 0 on, a b c and d should be Low. So I connect all the 4 pins to Ground and tested it out. Pin 0 is on, but all the other Pins are also, so my IN-14 lights up all 10 numbers, instead of only one. I have also tried it with Pins 2 or 3. The result stays the same, all the ouput pins of the K155ID1 go to high, making all the numbers in my nixie light. I have tried now several drivers and serveral nixies, but no difference. Anyone can help me ?

    Note: Im using 180v for the nixies and a 10k resistor on the anode. The K155ID1 is connected to 5V (from arduino).
  2. crutschow


    Mar 14, 2008
    Post your complete circuit diagram.
  3. ian field

    Distinguished Member

    Oct 27, 2012
    All (except one) outputs are supposed to go high with BCD 0 at the inputs.

    Only one output should be low at a time, so only one cathode is pulled down to draw any current through the common current limiting resistor on the anodes.
  4. RichardO

    Well-Known Member

    May 4, 2013
    I wonder if 180 volts is too high. Try lowering it to, maybe, 150 volts and see what happens.
  5. ian field

    Distinguished Member

    Oct 27, 2012
    For driving nixie tubes, 180V is practically an industry standard. But the parts in question are Russian copies of American parts, so inferior voltage rating wouldn't be a huge surprise.

    If a 150V zener presents difficulties, 51V types (x3) aren't all that rare. Alternatively, a TL431 can be casc_o_ded - I'd recommend a "grounded gate" MOSFET as it makes biasing much easier than providing stable Ib for a bipolar. A zener in the range 20 - 30V would be OK for providing stable Vg, the high voltage is sampled down with divider resistors to provide the Reg pin with 2.5V exactly the same as with the bare TL431.
  6. alfacliff

    Well-Known Member

    Dec 13, 2013
    the things are copies of the 7441, and the nixie outputs are only rated to 50 volts. they have zenner clamping to prevent damage, the zenners are turning on with the higher voltag.e
  7. ian field

    Distinguished Member

    Oct 27, 2012
    Nixie tubes of Western origin may not work at 50V. So maybe have to order matching tubes from Russia to go with those chips.

    Short of seeking out some NOS of 7441, the decoder outputs can be casc_o_ded just as I suggested for the TL431 alternative to a 150V zener.

    But it starts to get a bit untidy with 10 patched on external transistors.