On Sun, Jan 29, 2006 at 10:55:05PM +0000, Folderol wrote: > No! It is definitely 1/c1 + 1/c2 ... > > The only alternative I know of is 'product divided by sum' which is > often easier to use. > > i.e. > > (c1 x c2 x c3) / (c1 + c2 + c3) Sorry, all wrong, as can be seen easily by considering the dimensions. The first one is 1/Farad, the second Farad^2. The rule is the same as for parallell resistors: The inverse of the equivalent value is the sum of the inverses of all individual values. 1/Ceq = 1/C1 + 1/C2 + 1/C3 + ... or for just two of them Ceq = (C1 * C2) / (C1 + C2) -- FA
