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KB2VXA > TECH 04.12.11 17:04l 40 Lines 1647 Bytes #999 (0) @ WW
BID : 10350_VK6ZRT
Read: GUEST
Subj: Re: G0TEZ > Leyden jar
Path: IZ3LSV<IW0QNL<IK6ZDE<VE2PKT<CX2SA<VE3UIL<VK6ZRT
Sent: 111204/1453Z @:VK6ZRT.#BUN.#WA.AUS.OC #:10350 [Boyanup] $:10350_VK6ZRT
From: KB2VXA@VK6ZRT.#BUN.#WA.AUS.OC
To : TECH@WW
H Ian and all,
So, where did the electricity go? It's been in the jar all along. Poor
Michael, I wonder how many times he was shocked putting the foil back.
The simple explanation of the electrolytic cap is it's a way of packing a
whole lot of microfarads in a small container. The key is an extremely
thin aluminium (most common but there is tantalum) oxide coating on one
side of a long strip of foil rolled up inside an aluminium can. The oxide
has an extremely high dielectric constant making it all possible, it's
built up to the desired thickness the first time the cap is charged (very
carefully) and the thickness determines working and breakdown voltage,
usually about 20% higher.
Oh, a microfarad is one million times smaller than a farad and they have
to be pure, any contamination and it wouldn't be a farad. I didn't know
they had cloning back then and another puzzle is how they control the
size of the clones, micro, nano, et al. Maybe somebody can explain that
while I go looking for that classic story of
Micro Farad and Milli Amp...
And now for something completely different.
We all know (or most of us do) about inductive hysteresis that makes
filter chokes possible. It also makes spark coils possible but I digress.
Now maybe someone can explain capacitive hysteresis that makes unpleasant
surprises possible.
Along those lines maybe a broadcast engineer can tell us what a Jesus
stick is and what it's used for.
73 de Warren
Station powered by JCP&L atomic energy, operator powered by natural gas.
Message timed by NIST: 14:48 on 2011-Dec-04 GMT
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