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Re: PE-rolled cap construction



In a message dated 3/19/99 2:35:42 AM Pacific Standard Time, tesla-at-pupman-dot-com
writes:

> 
>  Right now I am making rolled Aluminum Flashing / Polyethelyne
>  capacitorsand I just made a mistake: I cut the flashing but I forgot
>  to cut out a tab for the electrical connection. Can anyone think of a
>  good way to still make the connection without using any sharp objects
>  or taking away from the total area?
>  
>  Also, when I was calculating the size of the plates for the cap. I
>  thought of this: Using the right size material so that if there are
>  any or minor errors in construction that decrease/increase
>  capacitance, they will not change the capacitance more than several
>  100th's.
>  
>  Like on mine, the dielectric of the polyethelyne could be 2.0 (instead
>  of 2.3) and I would still have a .005 uF valued cap., you could vary
>  all the measurements significally and still have a the same value cap.
>  Well just an idea I had.
>  
>  Chris.
>  
Chris,

I built mine with the flashing cut into long, rectangular pieces with all
edges rounded and deburred.  Then I cut separate pieces that connect up to the
brass bolts on the case.  These pieces are about 1.0" wide and maybe 10" long.
They are bolted to the flashing with #10 screws and nuts.  One is on the
inside of the roll and the other is on the other end of the other piece of
flashing - on the outside end as it is rolled up in finished form.  I just
made sure the screw doesn't protrude through the nut and added a couple of
extra pieces of about 2" wide poly under the bolt head for protection.

Ed Sonderman