You guys have made me curious now about the other 'good' clock I have of his. I'm going to open it up and see if there are any other differences other than the obvious being tube board I used vs. the 'stock' one.
On Saturday, April 6, 2019 at 10:26:30 PM UTC-7, johnk wrote: > > Michael, I have to comment on the logic here. > > You say you have one that is quite OK and seem to use that fact to rule > out the effects mentioned by Nick. Actually, I consider that the parasitic > oscillations idea is reinforced by your fact, not denied by it. When a > circuit is on the verge of misbehaving there will be some that are OK and > some that aren’t. > > Obviously I can’t tell from here what the actual fault is. > > > > Capacitors. I am interested in the topic. Low ESR electrolytics are a > curse. [Remember that fuss about the “stolen” formula not being complete > and all the computer manufacturers being affected?] Some do seem to last > better than expected. Some fail quickly. The LED lighting industry is > possibly going to cause improvements. Those tiny electros that they hide in > the base of the globe really are stressed. And some sellers still quote the > expected LED life as that for the power supply too ! Oops. [And > Australian consumer law provides for lifetime warranty btw, regardless of > what the manufacturer states. And we beat up Steam to the point that they > allow returns!] > > I am very interested in hearing about how well different brands and types > of capacitor perform. Anyone tried non-electros? > > I have noticed that some switching supplies driving discharge tubes for TV > and laptop backlighting [yeah, old ones, not LED ones] use monolithic solid > caps. One I fixed had only 2uF though iirc. A pity that opamp capacitor > multipliers don’t store energy J . > > > > John K > > Australia > > *From:* [email protected] <javascript:> [mailto: > [email protected] <javascript:>] *On Behalf Of *MichaelB > *Sent:* Sunday, 7 April 2019 11:06 > *To:* neonixie-l > *Subject:* Re: [neonixie-l] Another Tube Hobby Failure > > > > HI Nick, > > > > I know you have mentioned that before, but I really don’t think anything > else is wrong. As I said I have another one of these with 566M tubes and it > has worked flawlessly for 8+ years. Those electronics are in a similar > enclosure with less ventilation. And this is the second set of electronics > i have tried in this enclosure thinking there might be something internally > wrong with the PCB. (I had that problem with one of my Thomas clocks way > back when) But, I believe others have had issues with these electronics. > Another variable vs. your clocks might be that I have wired in a pair of > NE-2 Colons in parallel vs. the stock config that uses just one per each > side. I doubt that would be an issue, but it may account for a slightly > greater current demand. I don't think these clocks like anything, but an > open air set up. Also, the close proximity of the 5V VREG and the IRF640 is > somewhat suspect from a heat dissipation perspective. Anyway…I used a > higher voltage capacity electrolytic this time, maybe I’ll this'll give me > another year or so :-). and I will try your idea of adding a heat sink to > the VREG, since heat seems to be the culprit here. Thx Nick > > > > > > On Saturday, April 6, 2019 at 6:06:36 PM UTC-7, Pramanicin wrote: > > Something else is awry there Michael. I have a friend with a TubeHobby > IN18 that i built for him that’s been running for well over 6 years now > with no issues. The only modification i ever made was putting an extra > heatsink on the regulator as what was there (board plane) didn’t seem > sufficient to me (just a hunch, I’m sure Jonas knew what he was doing..).... > > > > Hope you get it sorted! > > Sent from my iPhone > > > On Apr 6, 2019, at 17:15, MichaelB <[email protected]> wrote: > > This makes 4 times now this clock has failed over the past 10 years or so. > This is a stock clock with IN-18's. I have another set of these electronics > that has never failed, but then again, I had changed the tube board to > accommodate the Z566M tube. Different current demands? It has worked like a > charm for years now. The failure with the IN-8 clock this time was a leaky > C6. In the past the inductor has failed, but usually its one of the > electrolytics in the Pwr supply stage. It's become kind of a ritual where > every 2-3 years I have to pull the clock apart and play detective and > figure out what's wrong after its starts blowing fuses. Kind of fun now, > actually! > > -- > 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/07394dde-1d45-4e3f-a38a-75ca15d16c48%40googlegroups.com > > <https://groups.google.com/d/msgid/neonixie-l/07394dde-1d45-4e3f-a38a-75ca15d16c48%40googlegroups.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > > <Tube Hobby Pwr Supply Schem..jpeg> > > -- > 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] <javascript:>. > To post to this group, send email to [email protected] > <javascript:>. > To view this discussion on the web, visit > https://groups.google.com/d/msgid/neonixie-l/22340da1-4f58-4673-bb1d-a9bdebb8fd14%40googlegroups.com > > <https://groups.google.com/d/msgid/neonixie-l/22340da1-4f58-4673-bb1d-a9bdebb8fd14%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. 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