Hi Gregebert, yes, I've checked the tube several times. The cold resistance is about 2,1 ohm, which is identical to the other tubes. Just swapped the tube with a running one on the same driver board. Sadly, no function at all. Under a microscope, no crack is visible.
I've made a short video to show the difference between a neon-nixie and a nimo crt-tube and a neodym magnet (very small one.) https://www.youtube.com/watch?v=JJytnrvTy3Q gregebert schrieb am Freitag, 2. Oktober 2020 um 19:25:40 UTC+2: > Jorg - Regarding the dead tube, have you compared the filament resistance > of the bad tube to the others ? > > NIMO tubes have 2 parallel filaments, so if one is open, the resistance > will be TWICE the value of a good tube. > I think the cold resistance is around 3 ohms. > > If 1 filament is out, you can still get 5 numerals to work. > > I would be surprised if both filaments are burned-out, unless someone put > way too much voltage on it, or the tube is cracked around the pins. > > If the filaments are OK, power-up the tube and make sure you get around > 180mA of current. > Then try varying the voltage between the filament and the logic driving > the grids. If a grid is about 6 V more positive than the filament, you > should get a numeral to turn on. > > On Thursday, October 1, 2020 at 1:44:20 PM UTC-7 jörg wrote: > >> Short update of my nimo project. >> I've got 5 tubes running. The sixt is unfortunately DOA. >> The tubes filaments are driven with three power supplies, with soft start >> IC (load switch). >> So the filament gets started very smooth. >> I've made some experiments with multiplexing the tubes. >> Which work nice, using the method described in the manual. The bias >> voltage is changed for every tube, that should be on/off. >> In the actual approch, I'm using direct driving the tubes via 74HC595 >> shift registers. Got a plenty of problems at the beginning. >> The power and signal lines for the 595 were messed with switching noise. >> Some caps did the trick. >> Really nice to view the working tubes. >> >> Video: https://www.youtube.com/watch?v=JbwfZhYhnlo >> >> jörg schrieb am Mittwoch, 15. Juli 2020 um 18:01:18 UTC+2: >> >>> I‘m using Eagle to layout. >>> It takes time for me to feel comfortable with it. >>> And Fusion360. >>> >>> -- 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 view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/c054d2eb-aa8a-4bdf-a6e3-f7cb292d4fb0n%40googlegroups.com.
