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Re: Blown Rolled "Hull" Capacitor Discussion



>Date: Mon, 25 Mar 1996 04:22:09 GMT
>
I wrote
>I just blew my second cap:(
>
>It was 3 layers of 0.030" polyethylene between 14" by 93" Al flashing.
>The rolled assembly appears to have settled in the container and the
>Al flashing is now resting on the plexiglass support leaving only a
>few mills of clearance between the plates.
>
Nope! a 1/16" hole clean (actually very black, melted the layers
together)  through the 3 layers of 0.030" polyethylene. The hole is
about 1.25" from the bottom edge of the plastic and about 2' from the
inside center of the roll.

I followed the most of the instructions. Pulled a vacuum, filled with
oil. Ran the TC at low power for a couple of evenings over 2 weeks,
this is where I deviated! I did not run at 60Hz only for a week!

I've run the coil for almost a month now with no problems. Then last
night when I ADDED a second toroid RFI filter to my RFI safety
circuit, the cap blew at 120Vac into the 15KV -at-60ma. neon.

Each half of my primary circuit is: 1/2 neon winding, safety gap to
gnd, bypass cap to gnd (500pF 2 layers of 0.040" PVC), 2.25K 100W
series resistor, 2 RFI chokes 2mH each (100 turns of #24 on Arnold
toroids from Hosfelt)

Shunt spark gap (cylindrical, 7 gaps, 0.030" each gap) then my primary
cap(11.4nf measured ) in series with my primary coil (15.5 turns taped
at 14 turns, inverse conical 11" inside diameter 31" outside).

Any thoughts? Where did I blow it:)

	sizzle jim