I use my own designed converters and it’s real nice knowing how the supply works so you can diagnose issues like this. I’ve used the design in a lot of clocks and never had a problem except in one clock which, after a while, started showing signs of distress - tubes not being full brightness, flickering, noise etc. my converter can be driven with anything from 3V to 24V, but this one was using an apple 5V USB adapter rated at 2.1A. Turned out the adapter was flaking out on me, which was a relief. I didn’t want to discover an issue with my design! Anyway, the moral is: Don’t trust the adapters, but also start the diagnosis with the stuff that is easy to change before you open up the case and get in to the electronics.
On Friday, February 20, 2026 at 7:03:36 AM UTC-8 JBro63 wrote: > *What is the brand of the power supply you are using for this clock? * > *Was the same wall wart used during both failures? * > This was from an old BT router I'd hoarded I think, 12v 1.2A, branded > I.T.E. It was the same PSU in both failures. Output is 13.8v so lesson > learned not to make assumptions about these things and to check in future > before use. > > *Is it the same model of wall wart as your other clocks are using?* > No, others use mix of 12v 1A for the IN-12s (4 & 6 tube versions) and 12v > 2A for an IN-18 (6 tube version) - bought new recently unbranded from > Amazon. I've measured these and they're ok for 12v. Not checked for spikes > yet. The IN-18 uses the bigger Omnixie 6300. > > *Do you run another clock which has exactly the same PCB and design as the > device of concern?* > Yes, I've had a build frenzy recently and have 5 identical IN-12 / K155ID1 > / 8200 models. It's 2 of these that I've had the failure on - both were > powered by the exBT PSU. > > > *Do you own an oscilloscope to look at the 12 V rail?* > Yes, a very old one. I have recently bought new probes so will be a good > excuse to fire it up / learn how to use it. Should this be measured under > load? > > I've added the capacitors as suggested above. Still awaiting the TVS > diodes. Luckily there is enough room in the cases for them to be added > unseen. One other benefit of the capacitors has been reduction in high > pitched whine the HV boards emit. > > Thanks for the tip the PSUs. Farnell stock them > > Thanks again all. > On Thursday, 19 February 2026 at 08:12:55 UTC Tomasz Kowalczyk wrote: > >> What is the brand of the power supply you are using for this clock? >> Was the same wall wart used during both failures? >> Is it the same model of wall wart as your other clocks are using? >> Do you run another clock which has exactly the same PCB and design as the >> device of concern? >> Do you own an oscilloscope to look at the 12 V rail? >> >> I suspect the issue is just failing/poor quality wall wart. I've seen >> cheap 12 V LED power supplies create spikes exceeding 16 V. Some time later >> the 16 V rated capacitor inside the PSU exploded. In your case, the >> NCH8200HV gave in first, for one reason and another. The absurdally large >> capacitor the designer recommended is meant to filter any garbage poor >> quality wall warts generate, but I think it's smarter to just invest in >> reputable wall warts and skip all of this nonsense altogether. My >> recommendation are Mean Well power supplies, they are not only reliable, >> but also electrically quiet. I used mostly GSM series. >> poniedziałek, 16 lutego 2026 o 15:43:11 UTC+1 Richard Scales napisał(a): >> >>> I've just tried one of those and for sure it works though I don't think >>> that USB-C with PD capability is as ubiquitous as some suggest. >>> For myself I prefer to distribute 12v from beefy 10A supplies to >>> individual clocks but that's only really because of the number I like to >>> display. >>> For regular folk I can see that USB-C-PD could work well. >>> >>> - Richard >>> >>> On Mon, 16 Feb 2026, 14:23 David Pye, <[email protected]> wrote: >>> >>>> I'm moving to try to power mine from usb-c as there are a range of >>>> autonegotiation boards that can request supply voltages from 5-24volt from >>>> a suitable PD PSU. >>>> >>>> David >>>> >>>> On Mon, 16 Feb 2026, 14:08 newxito, <[email protected]> wrote: >>>> >>>>> By the way, my attempt to make a similarly flat nixie power supply >>>>> failed miserably. I tried using the CJ5143-ALC flyback transformer which >>>>> is >>>>> 4.6mm high. It worked somehow but I was never happy with my design. >>>>> >>>>> -- >>>>> 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, visit >>>>> https://groups.google.com/d/msgid/neonixie-l/2976622b-1c50-4cf0-804a-6a3d37c95346n%40googlegroups.com >>>>> >>>>> <https://groups.google.com/d/msgid/neonixie-l/2976622b-1c50-4cf0-804a-6a3d37c95346n%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>> . >>>>> >>>> -- >>>> >>> You received this message because you are subscribed to a topic in the >>>> Google Groups "neonixie-l" group. >>>> To unsubscribe from this topic, visit >>>> https://groups.google.com/d/topic/neonixie-l/myKhY_ZZl4Y/unsubscribe. >>>> To unsubscribe from this group and all its topics, send an email to >>>> [email protected]. >>>> To view this discussion, visit >>>> https://groups.google.com/d/msgid/neonixie-l/CAOQ6x0F8Gm6prhsG6CYEdEh8NOi-dS94quk6-D%2BXh%2BH_jCsXkg%40mail.gmail.com >>>> >>>> <https://groups.google.com/d/msgid/neonixie-l/CAOQ6x0F8Gm6prhsG6CYEdEh8NOi-dS94quk6-D%2BXh%2BH_jCsXkg%40mail.gmail.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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