How about monitoring the Nixie tube current instead of light output. I have a strong suspicion that there's a good correlation between the two.
>From Tom Holmes, N8ZM > On Jul 15, 2016, at 11:40 PM, jimlux <jim...@earthlink.net> wrote: > >> On 7/15/16 5:25 PM, Bob Camp wrote: >> Hi >> >> You can do a pretty good job with a high speed photo diode. They are not >> cheap, but >> you can get fast ones if your Visa card is up to it. >> >> The next layer will be that at the relatively low strike voltages normally >> used, Nixie’s don’t >> light up consistently. You either need to compensate for temperature and >> ambient light / then >> calibrate each segment or sense each one as it turns on. Either way … it’s a >> major learning >> experience just to get it into the microseconds range. You can get to >> nanoseconds, but that >> may or may not be possible with conventional Nixie’s. > > Preionize the gas with a radioactive source. If it works for Krytrons, it can > work for Nixies. You could also use a pulsed ion source that turns on > slightly before the "top of the second" to irradiate and prepare the Nixie. > > A true time-nut won't let such thing stand in the way of perfection. > > >> >> Once you have them turned on, you go back through something similar when you >> turn them >> off. It takes a bit of time for all the little gas molecules to go back to >> rest state. The data I have seen >> on that sort of thing suggests a “many microseconds” to millisecond decay >> process depending >> on the gas and how it was driven. > > Turning an ionized gas off is always harder than turning it on. Perhaps a > tailbiter type circuit or a negative pulse generator? > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.