Hey everyone -- It's been a long time since I've posted to this group (or played with Nixies for that matter).
I've built an IN-13 driver circuit, using a topology that seems to be the "canonical" one most commonly floating around the web, using an opamp and an MPSA42 -- see the linked schematic: http://puu.sh/iNgTq/3f60ecf956.jpg All values are measured full scale indication conditions. I'm using a Taylor Edge supply module set at 146V (as indicated on the schematic; I know my handwritten 4s looks like 9s to some people). I originally had it set at 140V, but one of my tubes wasn't reliably striking at 140V, so I changed the set resistance. Thing is, all the documents on the IN13 that I've seen indicate that the control current should be on the order of 0-5mA. With the tubes I've got on hand (I've tried this on 3) the control current required has been on the order of 13mA to get the bargraph to indicate full scale. The question is, why to I need 3x the rated current to get full scale? It seems like I MUST be doing something wrong, but I'm not seeing what it could be. I suspect this isn't good for the tubes long term, but I'm also not sure how bad it is. As an aside, I tried 392k resistors on the cathodes and those gave me a slightly less linear sweep but overshoots the full scale indication slightly, which is nice. If there's no long term harm in upping that resistance, I'll probably go back to the 392k resistors. Thanks! -Bill -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/CABKLWSFP%3DrReVhHnWMORsRKQxBU2rjuHZw2nL-fG3Gn0V%3DBWcw%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
