LM3916 to drive an IN-13 nixie?

Discussion in 'General Electronics Chat' started by greendean, Apr 26, 2009.

  1. greendean

    Thread Starter Member

    Dec 20, 2008
    19
    0
    ok, so i have a whole working circuit here with a LM3916 driving a bar of 10 LEDS. Big whoop.

    I want to convert the output signal to drive my IN-13 nixie tube.
    I have the power supply and all the stuff to make the IN-13 light up.

    But what to I put between the LM3916 and the JE340 NPN transistor?

    Would a simple array or resistors do it.
    Would i have to change the NPN transistor to a PNP?

    i have tried many different circuit designs to get this IN-13 to move over the past couple monthes and nothing. So I just built the LED driver which works and now would like to convert it to the IN-13.

    Thanks for any help.

    -Dean G
     
  2. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Dean,
    Since the IN-13 Nixie tube probably isn't being made anymore, can you provide a datasheet for it, or at least a link to a datasheet?

    Do you have at least a partial circuit diagram, since you mention a JE340 transistor?

    The LM3916 will sink current from it's outputs according to what you've programmed with R1 & R2. You could use the outputs to drive the bases of PNP transistors, like 2N2907's or 2N3906's. You could then connect the PNP collectors to the bases of NPN driver transistors using resistors to limit the current.
     
  3. bertus

    Administrator

    Apr 5, 2008
    15,649
    2,348
  4. greendean

    Thread Starter Member

    Dec 20, 2008
    19
    0
    Here's the data on the IN-13.
    You supply the anode with 140volts. (I have the power supply for that).
    The auxiliary cathode get grounded through a 220K resistor and acts as a pilot light to make it light from the bottom and not the center.
    And the control cathode is, well, hooked to a control circuit (transistor).


    [​IMG]
    [​IMG]
     
  5. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
  6. greendean

    Thread Starter Member

    Dec 20, 2008
    19
    0
    i have seen both those pages.
    they are what is driving me to build my own.
    the kid that built the 14 tube version is missing ALOT from his schematics.
    i contacted him and he can't seem to figure out what it is he did. so either he had alot of help or just doesnt remember what he did while building it.

    the page with the two tube version is also questionable. i have built his and had to tweek it a bit and still no luck.

    i have build both circuits and neither produce results.

    I found a couple other sites about the IN-13 and they all share the same MJE340 transistor controlling one cathode and the other cathode grounded through a 220K resistor. I have had this set up working on a trimmer so i know thats correct.

    I have built the LM3916 LED bar graph display and know that it works as well.

    So I KNOW that these two systems work. Definitely.

    Now I just need to figure out how to marry the two.
     
  7. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    OK.

    Connect the emitters of ten 2N3906 transistors to your Vcc source of the LM3916.
    Connect a base of each 2N3906 transistor to each of the LED outputs of the LM3916. If you want to have the benefit of the LED's display at the same time (good idea while you're "tweaking" it) then connect the bases to the LED's anodes instead, leaving the LED's cathodes connected to the LM3916's outputs.

    The tricky part will be the resistors you'll need from the collectors of each 2N3906 to the base of the MJE340 to control the collector current. ST Microelectronics' datasheet gives very different values for hFE than does Motorola's. Gain may be anywhere from 30 to 240. You'll have to manually tweak each range.

    You should probably use a resistor between the MJE340's collector and the cathode of the IN-13 (or from the anode of the IN-13 to B+) so that you can't exceed the 4.6mA maximum current. I don't know what the resistance should be offhand, but somewhere around 30k would be a good start. Then check the current and adjust as necessary.
     
  8. greendean

    Thread Starter Member

    Dec 20, 2008
    19
    0
    Thanks wookie.

    That's what I thought I would have to do but I was questioning my judgement.

    I knew it had to be that simple.
    Like I said I had both halves it was just a matter of marrying the two.

    Once I get some transistors I'll toss it together and let you know how it comes out.
     
Loading...