@Bill van Dijk It's 1x6 multiplexing actually. Posted schematic is not mine, I used it just as reference. It seems someone mixed tube connections as well. I tried adding resistors before, but without success.
@gregebert I am not using PWM yet, but I am planning to do so, to make automatic dimming of nixies. I am not sure how it will interact with multiplexing. Taking into account all your ideas I worked on timing again. First I added 700ms delay inside interrupt before switching next anode on. I know it is huge no-no, so I rewrited all multiplexing to the main loop and add some delays - experimentally found I need 1ms after switching off all anodes and 3ms before switching them off. Thank You for all your time and help. I may return to this post if implementing pwm will challenged me. czwartek, 7 stycznia 2021 o 21:09:11 UTC+1 gregebert napisał(a): > It looks like you are using PWM dimming. Can you disable it for now, and > then focus on optimizing dead-time between cathodes and the anode timing. > > I'm fairly certain you want to turn OFF the anode before changing the > cathode signals, allowing some dead-time, then turning on the next anode. I > cant tell from the waveforms above if there is any dead-time or > overlap/underlap. > > On Thursday, January 7, 2021 at 11:05:27 AM UTC-8 Bill van Dijk wrote: > >> This is a 1x4 multiplex, each tube is lit 25% of the time if no “dead >> space” is built in the software. I have not checked the data sheets, but it >> looks strange that the 0 output from the 74141goes to the 1 of the tube, >> and so on. Anyway, with your problem, program a space between switching >> digits, length to be experimentally done since different tubes switch >> faster than others. The other thing to try is a resistor of a few hundred K >> between the tube anode and ground to dissipate the space charge in the tube >> quicker. (not sure if that works; I have not tried that myself). Generally >> speaking it is not recommended to multiplex Nixies, it surely dims them. >> >> >> >> *From:* [email protected] [mailto:[email protected]] *On >> Behalf Of *Mateusz Dziuba >> *Sent:* Thursday, January 07, 2021 1:27 PM >> *To:* neonixie-l <[email protected]> >> *Subject:* Re: [neonixie-l] IN-4 ghosting, once again. >> >> >> >> I did not develop specific circuit diagram for my clock, but it is build >> around this project: (please don't mind wrong polarity of opto. Someone >> draw it wrong.) >> [image: e44b2492e18895184e259a89f71556fc.jpg] >> >> czwartek, 7 stycznia 2021 o 18:32:35 UTC+1 Bill van Dijk napisał(a): >> >> Can you post the schematic? First I notice that a bright 1 has a ghost 2, >> and it seems every number has a ghosted lower number. Could be timing >> (discussed many times), or perhaps the KD1551s are too slow depending on >> your multiplex speed. What is you multiplex sequence, i.e. 2x3, 3x2, 1x6 ? >> >> >> >> Bill >> >> >> >> *From:* [email protected] [mailto:[email protected]] *On >> Behalf Of *Mateusz Dziuba >> *Sent:* Thursday, January 07, 2021 12:21 PM >> *To:* neonixie-l <[email protected]> >> *Subject:* [neonixie-l] IN-4 ghosting, once again. >> >> >> >> Hi all, >> >> >> >> I am working on nixie clock and experiencing ghosting between neighboring >> tubes. Please see attached photo. >> >> >> >> [image: 1.jpg] >> >> >> >> I am using 6xIN-4 nixies, Arduino with Atmega328, 6xTLP627 transoptor for >> driving anodes and K155ID1 chip for driving cathodes. I am multiplexing >> nixies in interrupt. Code attached. >> >> >> >> What i tried so far: >> >> 1. I connected 10x 1N4148 fast switching diodes from cathodes bonding >> points to mid voltage of 90V. It didn't help a bit and increased power >> consumption only. >> >> 2. I removed the diodes and tried "center-pull" all anodes and cathodes >> bonding points through 500k ohm resistors. Didn't help, although reduced >> decay of anodes after switching off. >> >> >> >> Some photos below: >> >> [image: 4.jpg] >> >> [image: 5.jpg][image: 2.jpg][image: 3.jpg] >> >> >> >> What comes to my mind, I might try to increase/rewrite blanking interval >> but i am not sure how to do it inside interrupt. Maybe I should rewrite it >> to the main loop. >> >> >> >> All help, comments, suggestions are welcome. >> >> -- >> 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 view this discussion on the web, visit >> https://groups.google.com/d/msgid/neonixie-l/ed921226-078c-4a66-bae2-bf79fad2b9b8n%40googlegroups.com >> >> <https://groups.google.com/d/msgid/neonixie-l/ed921226-078c-4a66-bae2-bf79fad2b9b8n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> >> -- >> 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 view this discussion on the web, visit >> https://groups.google.com/d/msgid/neonixie-l/e3a07d84-34e0-4f4a-9ab1-65ff8e128d2dn%40googlegroups.com >> >> <https://groups.google.com/d/msgid/neonixie-l/e3a07d84-34e0-4f4a-9ab1-65ff8e128d2dn%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. 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