Function of component in flash tube trigger circuit?

"James Sweet" wrote in news:RcIRj.3347$WS1.1332@trndny04:

your shockwave theory appears correct;

--
Jim Yanik
jyanik
at
kua.net

there

surely there is only microbar of pressure in a xenon tube? so nearer a vacuum "in space no one can hear you scream"

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

According to an article I found, the pressure ranges from .01 to .1 Bar, that's a LOT of gas compared to the vacuum of space.

You can get audible shockwaves in Nixie tubes by driving them multiplexed. Those have a pressure of only a few mm.

I kind of doubt it, at least not at any level of probability that matters. :)>

Agreed if it's a real leak. I suppose it's possible for there to be some sort of internal contamination that manifests itself usage.

If you have the flashlamp, you could test for ionization.

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There's rather dramatic shock wave inside when the lamp fires. This is transmitted via the walls of the tube to the air outside. Keep in mind that the pressure in these is a significant fraction of 1 atm, not like a neon sign or HeNe laser!

Is there a question buried here somewhere? :)

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Actually, no. It may be near 1/2 atm.

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gaslighter

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Now I've separated the tube from the reflector enough to clean the tube in the area where it descends through the reflector

I can now see all is not well. The cloudiness in the cathode end of the tube (only) is on the inside and there is a patch of distinct blackening marked with a yellow line. General black background is conductive foam for picture contrast , the yellow wire is the trigger wire connected to the loops around the tube, no silvering. The gaps 2 turns up of the spiral wrap at both anode and cathode, would they be breaks or like that at manufacture? It is after all 25 years of commercial photo studio use. The slave action via LDR also checks out

Powering up, switching off, and triggering with piezo and measuring before and after V then 42 joules per discharge per beacon tube. It may be advantageous to wire in a pair more of these beacon tubes to make 4 , to spread the load, at 2.50 GBP each compared to 70GBP for a not exact size and fit single tube replacement.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

The issue of the 2 turns of wire is probably irrelevant. The discoloration is also not surprising after a lot of use. What do you want from the poor thing after 25 years in a studio environment?

How much is your time worth? Kludging something with cheap flashlamps may result in it failing quite quickly. If you're just doing this to be able to demonstrate that it works, fine. If this is for a pyaing customer, install the proper flashlamp!

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