Oh that's a great website! Thanks for posting the link. The tube I tested is the SZ3-1
On Thursday, April 1, 2021 at 6:59:36 PM UTC+2 严泽远 wrote: > There're over 17 different versions of Chinese QS30-1 tubes (SZ1-1, SZ3-1, > SZ-8 are all same with QS30-1 but different brands), just curious which one > you tested. > Check the pictures here: https://www.nixieclock.org/?page_id=3162 > > [image: qs30-1.jpg] > > 在2021年4月1日星期四 UTC+8 上午7:26:11<David Pye> 写道： > >> Surely you've effectively got 10 of those resistors in parallel so the >> tube current is 10x rated.... >> >> Poor old anode.... >> >> David >> >> On Wed, 31 Mar 2021, 23:02 Jon, <[email protected]> wrote: >> >>> You're putting AC across the tube? In addition to what Paul said, think >>> about the scenario in the negative half-cycles. There you've got ten >>> 'anodes' (the display digits, normally cathodes) each with their own >>> resistor pouring current through one 'cathode' (the normal anode box/grid), >>> which is definitely not sized for that current flow nor designed to have >>> the glow on it bombarding its surface with lots of energetic particles. So >>> all bets are off on tube behaviour in my view. >>> >>> In either polarity of the cycle, the common electrode might be seeing >>> 22.5mA through it if your initial calculation holds. But very likely it >>> doesn't, because that calculation assumes the normal tube maintaining >>> voltage which I would have no confidence in being the case under these >>> conditions. If the maintaining voltage drops significantly when the tube is >>> run like this, then your current flow will be even more than you calculate. >>> Maybe that's how you get to 9W. >>> >>> Ouch. Wouldn't bother putting that tube in a clock! >>> >>> Jon. >>> >>> >>> On Wednesday, March 31, 2021 at 10:34:06 PM UTC+1 Paul Andrews wrote: >>> >>>> You should calculate the anode resistor you need for one segment. Use >>>> that, then connect all the cathodes to ground. I have done this many times >>>> accidentally. Now the hand waving part: Imagine the connection between >>>> the >>>> anode and cathode is a resistor and you connect all of the cathodes >>>> together - you are putting all of those resistors in parallel. You are >>>> limiting the current on each one to 2.25mA, so you are pumping 22.5mA >>>> through the one tube. I get that to be about 2W - (230-140)*0.0225. >>>> >>>> On Wednesday, March 31, 2021 at 4:11:49 PM UTC-4 gregebert wrote: >>>> >>>>> Very interesting; thanks for posting. >>>>> >>>>> You might want to try successive numbers of lit cathodes, say 01, then >>>>> 012, then 0123, etc and see how the current increases, and also see if it >>>>> changes over time due to heating. >>>>> >>>>> I dont recall seeing this behavior with segmented tubes, like the >>>>> 7971. In fact, on my clock I have a current regulator on each cathode, >>>>> and >>>>> another one for the anode, for every tube.....that works out to 128 >>>>> current >>>>> regulators on that clock. >>>>> >>>>> On Wednesday, March 31, 2021 at 12:18:08 PM UTC-7 Bill van Dijk wrote: >>>>> >>>>>> Just a guess, but I think by lighting them all up you get some kind >>>>>> of “super ionization” in the tube, which could then increase the current >>>>>> and heat dissipation. >>>>>> >>>>>> >>>>>> >>>>>> Bill >>>>>> >>>>>> >>>>>> >>>>>> *From:* [email protected] [mailto:[email protected]] *On >>>>>> Behalf Of *Yohan Park >>>>>> *Sent:* Wednesday, March 31, 2021 3:15 PM >>>>>> *To:* neonixie-l <[email protected]> >>>>>> *Subject:* [neonixie-l] Lighting all digits at the same time: Why >>>>>> does this happen? >>>>>> >>>>>> >>>>>> >>>>>> I have a few Chinese QS30-1 tubes lying around which don't have much >>>>>> value for me and was wondering how it would look to have all digits lit >>>>>> at >>>>>> the same time. >>>>>> So I looked up the specs which say 170V and 2.25mA >>>>>> So I calculated the needed resistor to have it hooked up to 230V >>>>>> which is a little below 27K >>>>>> I then connected a 27K resistor to one cathode and it lit perfectly >>>>>> fine (230V AC so the anode also glows). >>>>>> So I then connected 10x 27K resistors to all the cathodes and plugged >>>>>> it in. >>>>>> Holy Moly! The thing lit up like crazy and was drawing over 9 Watts >>>>>> and was getting VERY hot. So I turned it off again after a few seconds. >>>>>> Can anyone tell why it's behaving like that? >>>>>> >>>>>> -- >>>>>> 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/bffb114c-9810-4d65-8e98-ee13f6c860fcn%40googlegroups.com >>>>>> >>>>>> <https://groups.google.com/d/msgid/neonixie-l/bffb114c-9810-4d65-8e98-ee13f6c860fcn%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/c8c35a61-fa0a-4249-9311-47061c50865cn%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/neonixie-l/c8c35a61-fa0a-4249-9311-47061c50865cn%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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