Couldn't you wire in a small HV PSU module instead, and bypass the circuitry for that one?
Not sure that it would necessarily have a better lifespan (depending on who made it...) David On Sun, 7 Apr 2019 at 05:31, MichaelB <[email protected]> wrote: > You've described my experience with this clock to a "T". If I hadn't made > a custom enclosure around these electronics and its 'unique' tube spacing, > I would abandon it in a heartbeat and substitute NixiChron electronics, but > this would basically require building a whole new enclosure. It was my 1st > enclosure build so I'm a bit attached to it. So I'll keep my fingers > crossed and hope I can come up with a solution to this anomaly. Suggestions > welcome > > On Saturday, April 6, 2019 at 7:55:19 PM UTC-7, Roger Brinkman wrote: >> >> I have one of these clocks too and it fails every three years or so on >> average. It’s all down to C6. Sometimes just F1 fails and other times the >> inductor L1 goes short circuit as well. >> The Equivalent Series Resistance (ESR) of C6 goes through the roof, >> causing it to effectively be a capacitor in series with a resistance. This >> result is ringing in L1, and instability in the output voltage which >> increases L1’s heat dissipation and untimely failure. Ambient temperature >> is definitely a factor in C6’s lifespan, i.e clocks running in cooler >> climates may run longer before failing, but the real mechanism of failure >> is C6’s ability to withstand the internal heat generated by the pulse >> current as its ESR rises with age. The higher it’s ESR, the warmer it runs, >> then the quicker its electrolyte dries up. >> High quality, low ESR 105 degree electrolytic capacitors designed for >> pulse applications like the Panasonic WL-R series will have a longer life >> than ‘ordinary’ electros but eventually even they will fail. I have thought >> about substituting a Multilayer Ceramic Capacitor in place of electrolytic >> C6, but currently waiting for the next failure (which is about due!) before >> I experiment with them. Perhaps another person can comment on their >> suitability for such an application? >> >> Regards from Australia! >> >> On 7 Apr 2019, at 11:59 am, Mac Doktor <[email protected]> wrote: >> >> >> On Apr 6, 2019, at 9:36 PM, MichaelB <[email protected]> wrote: >> >> I used a higher voltage capacity electrolytic this time, maybe I’ll >> this'll give me another year or so :-). >> >> >> Are you using 85°C or 105°C? >> >> >> and I will try your idea of adding a heat sink to the VREG, since heat >> seems to be the culprit here. Thx Nick >> >> >> Never turn your back on a 78xx. You could try using a 317 instead >> (requires a resistor). >> >> >> Terry Bowman, KA4HJH >> "The Mac Doctor" >> >> -- >> 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 post to this group, send email to [email protected]. >> To view this discussion on the web, visit >> https://groups.google.com/d/msgid/neonixie-l/0DFF2801-AAC9-4780-9779-E01A35F1612D%40gmail.com >> <https://groups.google.com/d/msgid/neonixie-l/0DFF2801-AAC9-4780-9779-E01A35F1612D%40gmail.com?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> >> -- > 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 post to this group, send email to [email protected]. > To view this discussion on the web, visit > https://groups.google.com/d/msgid/neonixie-l/c55b7b6b-a7d7-4f50-8eb8-10bb79c6a208%40googlegroups.com > <https://groups.google.com/d/msgid/neonixie-l/c55b7b6b-a7d7-4f50-8eb8-10bb79c6a208%40googlegroups.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- 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 post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/CAOQ6x0FNksL1joauknKxZHCR15Dg4kVdCVduRTjh%3DP4p8Nw1tg%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
