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Re: Glassless Saltwater Caps
> Hello All,
> I have not done much coiling lately due to the lack of good caps. My current
> bank of caps are glass saltwater jobs, cheap and very bad. I would be very
> glad if you were able to describe the construction of these glassless caps,
> so that I can make some for my underpeforming coil. I would need about
> 0.025uF
> Thanks
> Andrew Meyer
Andrew,
I just gave up saltwater caps altogether. I kept blowing them up -
literally! 4 caps in one day! I just finished rolling my first set of
rolled poly caps and am breaking them in this weekend. Already, even
with my gaps set at 30% of full open, I'm getting stronger and longer
sparks than with my glass caps. I couldn't get the power I was looking
for.
I followed combo of Richard Hulls and Mike Hammer's design. I used a
roll of 6 mil poly from Home Depot, one roll of Reynold's Heavy Duty
Aluminum Foil, 3" PVC pipe, 1" PVC for the core. I cut my poly into 80"
lengths. When opened up, this then allowed 8 sheets, 15" wide. Out of
one roll, I got 3 sets of 8 pieces 15" wide which was enough for 3 caps
for me.
My needs were for 3 -.03uF caps wired in series for .01uF, rated at 40K.
I placed 4 poly, foil(12"X 76"),4 poly, foil. I rolled all this up and
tied it with nylon ties, fit it into 3" pvc.
The calcs showed I needed 73" of foil - I made them 3" longerso I could
place the terminals onto the foil, then wind it up to 73". Then when I
rolled it all up and clamped it, the foil was securely fastened to
terminals without any screws or clamps.
The terminals I made from the heavy duty foil as well. I cut a piece 32"
long, folded in half (lengthwise so it was 16" long) Then folded along
it's length over and over until it was about 3/4" wide by 16" long. I
taped this onto the end of the foil with the extra length extending out
beyond the poly. One on one end, one on the other end of the other foil.
For your size caps you'd need more. What's your voltage?
If you used the same design, You'd need 6 caps, 3 in series wired in
parallel with 3 others in series.
Your foil would have to be 12" by 85 1/2" long. Poly would have to be
90" or so. With calcs:
.224 X 2.0 X 1025 (foil sq. in.)X 2/ .024 (poly)= 38266 or .038266 uF
each. 3 in series would equal .01275. Wired in parallel with three more
would give you a total of .0255 uF.
I don't know if this helps or not. If I can help let me know.
Good luck!
Bob V