RE: barium titanate doorknob caps

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Terry Fritz" <twftesla-at-uswest-dot-net>

Hi Gary and Al,

Ok, now that we have all three had our say about my killing the barium
safety thread (which "I" am solely responsible for), let's get down to the
cool stuff.

Al, how in the world are you planning on making these caps?  I assume you
need fairly high quality clay (ceramic) and you need to fire it somehow
with interleaved plates inside.  I am very familiar with high power RF caps
like ATC makes.  The ceramic, plates, tolerances and such are pretty high
quality and tolerance.  But they are trying to make the caps small too.  So
making them simply in larger dimensions should ease that problem
considerably.  I can see aluminum foil with clay layers in between.  Air
bubbles in the clay could be a big problem.  I wonder if something like
plaster of Paris would be better.  However, the dielectric is still going
to have to be low loss or the heat will kill it.  Loss my be a problem with
red clay that I think is red due to iron oxides...  Not really sure...
Impurities could be a big problem too.

Maybe study the early days of ceramic cap making for tips.  They had pretty
"basic" tools back then so maybe their techniques would not be hard to
reproduce.  You have today's technology too to steer you in the right
direction and around problems the early guys had.  Since you may work with
far larger dimensions, perhaps much lower grade ceramics can be found at
much lower cost...

Cheers,

	Terry


At 07:59 PM 4/22/2001 -0500, you wrote:
>Hi Al:
>
>Please don't cast me as a sinister conspitator.  My goal was not to
>"outlaw" or stiffle discussion on new or different means of making
>capacitors, but simply to point out that the NUMEROUS posts on the topic
>snip...