I think most coilers would agree that the most troublesome component in a
coil would be the capacitor. Unless you have the big bucks to blow on a
commercial unit, the alternative is to build one and hope that it lasts.
Too often, after a laborious and expensive construction project, one's
cap ends up as just so much smelly. oily, burnt, expensive, useless poly
and flashing, and we wonder "where did I go wrong?" It would be nice if
we could all learn by other's successes and failures.
I would like to propose and volunteer to organize a survey of home-built
capacitors. I would like to focus upon sheet-plastic dielectric units,
both rolled and flat plate, rather than saltwater/bottles, which are
difficult to quantify.
I AM EQUALLY INTERESTED IN SUCCESSFUL UNITS AS WELL AS FAILED UNITS.
Below is a survey form, filled out with the details on my (failed) unit
as an example. Please delete my data and add yours, and return it to me
at lau-at-hdecad.enet.dec-dot-com. If you'be built several different units,
please make a copy of the form for each one. I promise to post the
compiled results on my web site and announce this on this list. Since I
don't plan on performing any digestion or analysis on this data, it would
probably be too large for a post to this List, unless our Moderator feels
otherwise? <<<<Large posts can overwhelm the server system so large files
are best to post elsewhere and tell us were to look. - Terry>>>>
Waltham, MA USA
Your name, email address:
Gary Lau, lau-at-hdecad.enet.dec-dot-com
Final disposition of capacitor: (continues to work great, or failed)
Nature of failure (or N/A):
One unit suffered a dielectric puncture at the edge of the foil plates.
There was no evidence of a margin arc-over.
Failure conditions (or how much run-time on surviving units):
Ran coil for approx 7 continuous minutes prior to failure. Caps felt
slightly warm over edges of foil plates prior to failure. Had several
successful, shorter runs prior to failing run.
Gaps (include total gap distance if static):
Static, single segment, vacuum motor air-quenched, 0.36 inch total gap
.04 inch LDPE from Cadillac Plastics
Pumped down with vacuum pump, back-filled with laxative-grade mineral oil.
Number of cap units (if series connected), dielectric thickness per unit:
2, one layer 0.04 inch LDPE per unit
Total dielectric thickness across all units:
Dielectric edge margin:
Capacitor details and other misc notes:
0.01 uF total series value over two identical units. Each unit measured
0.02 uF. Used extended foil rolled construction using household aluminum
foil. See http://people.ne.mediaone-dot-net/lau/tesla/capacitor.htm for