Re: Homemade paper capacitors...

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Original poster: "Jim Lux" <jimlux-at-earthlink-dot-net> 


 > Original poster: "Hydrogen18" <hydrogen18-at-hydrogen18-dot-com>
 >
 > I made a paper capacitor here:
 >
 >
<http://www.hydrogen18-dot-com/articles/oilpaper_cap/>http://www.hydrogen18-dot-com/
articles/oilpaper_cap/
 >
 > and impregnated it with 10w-30 motor oil. I get a capacitance reading of
 > 0.093 uF. Does this seem reasonable? I have about 12 feet of dielectric in
 > there which when rolled appears to be 24 ft by 2 inches wide. Also, does
 > anyone have any ideas about voltage rating? I dont have a wide range of
 > voltages available and have been unable to get a flyback to work... Thanks
 > for any help you can provide.

For a "normal" paper/oil capacitor, the oil is the dielectric, and the paper
merely a spacer.  How thick is your paper? Maybe you can calculate it by
measuring the diameter of the roll and dividing by the number of turns?

Voltage rating is going to depend a lot on imperfections in the paper (what
kind of paper did you use?) and the water content of the oil.

Dissolved water in either the oil or the paper (did you dessicate either
before starting assembly?) will change the loss characteristics as well.