OK, here's something, I guess... I found (after replacing a broken anode driver after blowing that, an ATMega, and possibly my entire cathode driver board) that if I kept one digit on one nixie tube lit (at 100% duty cycle), and then for a split second turned on the anode of the partner (so that digit lit up on the second tube as well), the digit would stay weakly on even if the anode was off (or even disconnected). Measuring the voltages around the semi-illuminated numeral, I found that the digits directly surrounding it were in excess of 120 volts, which I guess is enough to weakly ionize the grounded digit.
This makes me think-could pulling all cathodes low during the blanking period (while the anodes are both off) possibly help the problem? The pull-middles certainly helped, but I fail to see why a pull-middle is better than a "yank-down" in this case, considering that the anode will be off during yank-down. I have no way to test this ATM, due to the busted mega, but if anyone thinks this would/would not work I would like to hear it. On Feb 15, 9:58 pm, will <[email protected]> wrote: > Hmm... anodes and cathodes both show perfect square waves, with the > slightest of roll-off towards the bottom (probably due to my ghetto- > rigged "probe"). Weird. > > On Feb 15, 1:27 pm, will <[email protected]> wrote: > > > > > > > > > OK, thanks. BTW I bought an old heathkit oscilloscope last night (for > > $35. Thanks, craigslist!), so I'll try to get a voltage divider set up > > today (It will be a while before the attenuator probe arrives) and I > > should be able to better troubleshoot to see if it's a problem caused > > by leakage. > > > On Feb 15, 12:02 pm, threeneurons <[email protected]> wrote: > > > >http://snipurl.com/10zg1u > > > > Here's a video of the above clock running: > > > >http://www.dailymotion.com/video/xbqv51_nixie-clock-3_tech > > > > The flicker you see is the beat frequency between the camera's frame > > > rate and the multiplexing rate of my clock. In real life, no flicker. > > > The clock also has 'cathode poisoning prevention' scheme, which > > > briefly flips each tube to a different digit. I don't know if this is > > > really needed, since those tubes are never going to be flipped around > > > or used for anything else. Its been running since 2004. The IN-14s > > > still look like new. The 6802 dekatron's glass is a bit mirrored, but > > > not too badly. Only the NE-2 in the middle looks the worst for wear. > > > Maybe I stuck a limiting resistor in there, that was a bit too small. > > > I often switch the value of the part used, to something else, than > > > whats listed in the schematic. > > > > Do what I say, not what I do. -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
