I had a difficult time trying to measure the striking voltage because it's not consistent, perhaps because of random photons or background radiation. It's very close to the sustaining voltage.
Also, I couldn't measure low current easily. I took data down to 500uA, but below that the tube would extinguish rapidly and many numerals were partially illuminated. I wasn't able to take a measurement at 50uA or 100uA. When increasing the voltage, the current stayed at zero until ignition and then went to a few hundred mA. When reducing the voltage on an illuminated tube, the current suddenly dropped to zero. My equipment wont measure below 1uA. At high-current (6mA), the surface-area of the numeral seems to be the reason for variations in the I-V curves. The '1' and '4' have lower current for a given voltage (lowest surface area), and the '8' is at the top-end. Variation of voltage-drop for each of the 10 numerals at 500uA is very small, about 2 volts, even across different tubes. To me, that means the filling-pressure and mechanical construction are well-controlled. On Thursday, November 12, 2020 at 10:42:38 AM UTC-8 Dalibor wrote: > Greg: So far I haven't seen (and customers haven't reported) our tube to > drift with the striking voltage so much that it would not strike. I did > some random measurements on old tubes and after few seconds of normal use > (clock), all digits strikes at normal voltages. But we gave up on trying to > use striking voltage as an indicator - the same tube can differ by few > volts in dark/light. The important thing is that it always strikes below > 145V. > > Cheers! > > On Wednesday, 11 November 2020 at 23:15:04 UTC+1 gregebert wrote: > >> I had to generate that data by hand measurements....talk about tedious. >> >> Your measurements confirmed what I saw as well: the ionization and >> extinguishing voltages are pretty close to eachother. Generic neon bulbs >> have much higher hysteresis. >> I was not able to determine any significant difference in ignition >> voltage for a dark vs illuminated room. >> >> It would be good to see if there are any changes after the tubes have >> been in-service for awhile, say yearly checkups. >> >> I'm still waiting to get back on my feet so I can get my clock finished. >> They are magnificent tubes. >> >> On Wednesday, November 11, 2020 at 1:50:35 PM UTC-8 Jon wrote: >> >>> Thanks Kevin, this is really interesting stuff! >>> >>> Jon. >>> >>> On Wednesday, November 11, 2020 at 9:03:43 PM UTC Kevin A. wrote: >>> >>>> By the way, if you find the SMU instrument interesting, I wrote a >>>> detailed article about what it is, and how it is used: >>>> https://neonkev.com/2020/09/21/precision-swiss-army-knife-the-smu-source-measure-unit/ >>>> >>>> On Wednesday, November 11, 2020 at 4:01:23 PM UTC-5 Kevin A. wrote: >>>> >>>>> On Wednesday, November 11, 2020 at 4:01:01 PM UTC-5 Kevin A. wrote: >>>>> >>>>>> Some pics of the test setup >>>>>> >>>>>> -- 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/d21ed645-32d7-4c4e-85ec-3ea985aaf040n%40googlegroups.com.
