Re: New type of home made cap almost 4nf -at-at least 5kv

["Kevin D" <teslacoilfreak1-at-mediaone-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Hi Tom,

One reason your caps may be blowing is that the plastic from soda bottles
varies in thickness(do to the way there made)from one place to the next
which would cause stress
points(the thinner parts)also I've noticed that soda bottles offten have
alot of fine scraches a maybe a few deep ones
which would cause further stress points and probably corona which leads to
more rapid breakdown of the plastic.

The only major difference between a homemade cap and a commercial cap
weather it be rolled or stacked is the quality of materials and quality of
manufacture(the places where commecial caps are made are very clean and at a
low humidity to reduce the chances of "hot spots" on the dielectric that
dust or moisture may produce)also commercial manufacures use very smooth
fine grade plastics
to futher reduce the chances of "hot spots" or corona,so the
best way to make sure your homade caps do not blow is to use the best
quality plastic you can find and also to make your caps in a environment
that is as clean as possible e.g. free from dust,lint,cat or dog hair and
the like and also if possible where the humidity is under say 60%.

There are alot of other tips & tricks out there on home made caps so check
the pupman site and sites on the tesa coil webring for more info.but I think
as well as most list members is that a MMC is the way to go,you get
commercial quality at a fairly low price and the advantage of easy
configuration an repair and the bonus of your cap being self healing without
all the mess and hastle of homade caps.

hope this has heped some

Regards,
Kevin Dalpe