Well, I really like the vintage look of the Nixies and this is part of a bigger project. Basically I would like to transform an old valves radio, changing only the insides and snapping a Nixie spectrum analyzer on it.
But I am interested in your schematic, it sounds interesting, could you please share it? PS: any ideas on the initial email? I think I will have to switch to IN-13 either way because the consumed power (most probably) exceeds the limits of my power supply: 10 Nixies x 12mA each (average) x 180V = 21.6W and 10 Nixies x 20mA each (max) x 180V = 36W ...adding the rest of the circuits (active filters, lin-to-log) will be an additional 5-8W On Saturday, February 14, 2015 at 10:10:01 PM UTC+1, Mihai wrote: > > Hi all, > I know there are a lot of discussions on this topic and I believe I read > almost everything. Not sure I understood everything so that's why I would > like an extensive opinion on this matter. I recently bought some IN-9 > Nixies from eBay for building a stereo 10-channel spectrum analyzer. I > believe the schematic is very well known, Instructables - > http://www.instructables.com/id/Nixie-Tube-Music-Visualizer/. Well, aside > the modifications I made regarding the number of channels and the > lin-to-log converter, I have an issue with how the Nixies are lit; of > course, not all are lit from the bottom and their behavior are somehow > erratic. > I boiled down what I read to the points below: > 1. Burn-in - this was new to me - it seems that the tubes must be > burned-in prior to using them. My tubes are lit all the way up, just not > when they are supposed to. Do I still need to burn them? > 2. Driver stage - I've put together all the op amp driver schematics I > found, including the one in the original schematic (Instructables); there > are basically 5 variants for which I do have some questions > a. "blind" op amp driver + limiting current resistor - this is in the > Nixie documentation so it's the 1st building block > b. same as "a" + a pot for varying the current > c. same as "b" but interestingly, it has a resistor in the op amp's > negative reaction loop. What is its purpose? Does is raise the > amplification? > d. same as "b" but with a low pass filter. I understood this should fix > the IN-9 issue regarding firing up from the bottom. Question is: do I have > to have a low-pass filter tuned for each channel or is one for all? If it's > one for all, what should be the cut-off frequency? I found different > lox-pass Nixie filters and they were usually built with R=10k ad C=100n. If > we go with the RC low pass formula, we get ~160Hz for the given values > which I really don"t get what it's for > e. The Instructables schematic (see link above) mentioned a voltage > divider of the input voltage but ...how? Is the voltage divider using the > low-pass filter resistor for doing this? > > Either way, I tried almost all variants in my schematic and none has a > definitive and decisive result. I ended up with option "b" and the thing is > that some work almost fine, and some are firing up from a third from the > bottom. Sometimes they go in the middle but not always. > > Any opinions on the above? The HV PSU is digital with MAX1771 not analog > with transformer. For some reason, the voltage reading is not constant, it > varies - 145-170V > > PS: shall I give up on IN-9 and buy IN-13? I read though that it's not > guaranteed they will work absolutely fine. > > Thanks > > > -- 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 neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/4fec0648-25a9-46f9-9df7-7a7cc86a2521%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
