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High amp caps or something.
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From: Bill the arcstarter [SMTP:arcstarter-at-hotmail-dot-com]
Sent: Wednesday, February 11, 1998 10:41 PM
To: tesla-at-pupman-dot-com
Subject: Re: High amp caps or something.
Hi Joshua.
>From: Joshua Resnick [SMTP:seraphim-at-WPI.EDU]
...
>I felt to be amperage effects on the foil coming from the top of the
>stack. My roommate (college) believes that the melted foil was from
>flaming arcs from the simple gap we had setup that had touched the
...
Yep - I've seen this on some similarly constructed open-air/poly caps.
Didn't damage the foil but rippled the poly in my case. Here are my
thoughts:
--> Skin depth in pure copper at 200KHz is about 0.006 inch.
Therefore, using kitchen foil, even heavy-duty stuff is increasing
your effective resistance over the best achievable value. Skin depth
in aluminum is even worse (deeper). Instantaneous currents w/o any
appreciable series inductance can be exceedingly high!!
--> I doubt the current flow is uniform throughout the plates due to
electrostatic effects. I would think there would be both
electrostatic and magnetic (skin) effects which would tend to keep
most of the HF-currrent flowing along the outermost edges. (This
is where most caps seem to fail!!) But I may be wrong. Can anyone
comment on this?? ! Anyone want to run this situation through ANSYS
or something?
...
>Last question - I cut some microwave xfrms apart in a band saw and
...
I used a hatchet! Didn't have a saw handy. Pics pending...
http://www.geocities-dot-com/capecanaveral/hangar/6160/uwave.html
-Bill the arcstarter
Starting arcs in Cinci, OH
(More tube info pending for all that have responded...)
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