Re: Need Help With Capacitor

 Since my garage is about 20 degrees below freezing, I thought I would make
 some caps indoors.  I was thinking of using wide straps instead of the
 6 gauge wire that I used in my other cap.  The question is how wide is
 wide enough?  I was leaning towards a few 2" straps placed along
 the length of the conductor, thereby reducing inductance.  The conductor
 is about 10 or 12 mils thick aluminum.
 Chip ,
        The inductance of a straight wire in free space is:

        L = 0.00508 * b * ( (ln(2b/a)-0.75)

        L is in microhenries
        a is wire diameter in inches -- replace 0.00508 with 0.0002 for mm.
        b is wire lenght in inches.
        ln is the natural log or 2.303 times the common log (base 10 log).

        #6 solid wire is .162" in diameter. let's use 1'=12" as the length
        L= 0.00508 * 12 * ((ln(2*12/.162)-0.75) = 0.259uH. At
        200Khz  Z=2*pi*f*l= 325 miliohms.

        The inductance of a flat strip in free space is:

        L = 0.00508 * b * (ln (2b/(h+w)) + 0.5 + 0.2235(w+h)/b)

        L is in microhenries
        b = length in inches
        w = width in inches
        h = thickness in inches

        using 1'=12" as the length, 2" as width, and 10mils thick:
        L= 0.00508 * 12 * (ln(2*12/(0.010+2)) + 0.5 + 0.2235(0.010+2)/12)
        L= .184uH At 200Khz Z= 231 miliohms.

        Note that these formulie don't take into account skin effect, and
the material must be non-magnetic.

        I'm supprised, I had expected the inductance of the flat strip to be
MUCH lower!