Talk-Polywell.org

I am currently faced with an interesting design issue. I need to find a >20kv instrument (low power) connector into vacuum. Our primary connector vendor no quoted even though the connector I wanted was in their catalog. Back in the vacuum tube days I suspect that this would be easier that is now. As it is I'm thinking of using these:
http://www.isi-seal.com/urd/uniface.urd ... ay?2.3.5.3
and welding my own flange on it.
which is way more connector than I need. As of right now the only alternative is to come up with a design myself. It's interesting that nobody does low power high voltage connector as a standard and how little there is for vacuum where large parts of the instrument is inside vacuum. It seems as if the biggest vacuum users are the vapor deposition people and the accelerator type. Oh well.

How do electron microscopes manage ??

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OT: I remember having *great* fun adding a simple thermocouple to the shelf of a modest vac oven. In the end, I had to re-arrange the plumbing to pass a metre-plus 1/16" probe through the cross-bar of a T on the pump line. The final step, from 1/4" to 1/16", I did using a Teflon ferrule and an HPLC fitting. That, fingertight, would hold ~300 Bar, so had no problem with milliBars. Also, it was sufficiently far from the oven to stay within 10--60'C range rating...

How about using a spark-plug from a car?

http://www.teralab.co.uk/Experiments/X_ ... _Page1.htm

"Normally the electrical connections into the vacuum chamber go through the aluminium base plate. This would flash-over at 50kV. Luckily I had a spare bell jar with a hole in the top."

Worth asking: He'll probably refer you to an 'Amateur Scientist' column in old 'Scientific American'...

ps: {slaps own head} I've seen metric threaded spark-plugs...

This is for production, so I can't use and amateur fix. Fortunately we found a good vendor, Connectronics and have a solution. di require a custom part thought.

why not just use induction and make a transformer that's got the primary coil outside the vacuum vessel and the secondary inside?
I mean, you probably have to have a transformer anyway to hit that voltage...

WizWom wrote:why not just use induction and make a transformer that's got the primary coil outside the vacuum vessel and the secondary inside?
I mean, you probably have to have a transformer anyway to hit that voltage...

Unless you use resonant transfer the coupling is not so hot. And then if you want a regulated supply.....