Hi The gotcha is that it’s the sum of the radiation arriving in the vicinity of the gas. Supplying a bit can flood small variations, but they still are present. You are trying to get what is essentially a neon bulb to trigger accurately to a very tight budget. There is a lot of prior art on the pitfalls. Since you do not have a structure that was custom designed as a high frequency transmission line, there are a lot of lumps and bumps along the way…
The only real point is that going from millisecond to microseconds is a leap for these gizmos. Going from microseconds to nanoseconds (or picoseconds) is an even bigger leap. There *is* a way to do it, if your budget it big enough. It’s going to be a major effort all by it’s self. Being able to forward predict the process (which is the goal) at these levels has a lot of variables in it. Feedback does not help if you have second to second jitter that is all over the place….(gas tubes are used as noise generators for a reason ….). Bob > On Jul 16, 2016, at 11:36 AM, David <[email protected]> wrote: > > The point of measuring the actual ignition point is to predictably > remove delay by driving the element earlier. CRT grid structures > support transition times in the 5 to 20 nanosecond range; the smaller > distances involved with a nixie tube should support faster operation. > > Something which just occurred to me is that ultraviolet can be used to > provide ionization to the gas without radioactivity. Flame detector > tubes work like this so bathe the tubes in a small amount of UV. I do > not know how transparent the nixie tube envelope to UV is though. > > On Sat, 16 Jul 2016 11:04:22 -0400, you wrote: > >> Hi >> >> Since we have moved into synchronizing this stuff at the nanosecond level >> (maybe we are even lower than that by now ..), simply getting a wide band >> enough signal off of a Nixe socket is going to be interesting. An array of >> picosecond >> photo diodes on each tube may be the only way to go. How many channels >> this all will take depends a bit on how many digits past the second the >> display >> will show. Is it 9 digits past the second? >> >> Since you will only know the ignition point *after* it has happened, the >> system >> only works to a certain degree. Trigger point *is* dependent on the light >> level. >> You will need to collect real time data to keep things consistent. >> >> Bob >> >>> On Jul 16, 2016, at 10:49 AM, David <[email protected]> wrote: >>> >>> Use AC coupling to each digit to measure the ignition waveform and >>> detect the breakdown point like with a tunnel diode trigger. Use a >>> higher compliance voltage and greater negative resistance (constant >>> current drive?) to lower breakdown jitter. > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
