[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Capacitor - series?



Original poster: "Gerry Reynolds" <gerryreynolds-at-earthlink-dot-net> 

Luke,

You were and are correct.  If they are different values, they won't see the
same voltage.  Two approaches have been posted, one feeding the series
string with a constant current source and integrating.  Vc = I*time/C.  The
smaller cap will need a larger voltage rating because the voltage will grow
faster than the larger one.

The other looks at the problem as an impedance at a given frequency.  The
voltage will divide as   V * Zc1/(Zc1 + Zc2) where the Z of a capacitor will
be 1/(2*pi*freq*C).  Either approach will give the same answer.

For your particular example the 1nf cap had a voltage rating 10x that of the
10nf cap which is correct to match the ratings.  Example, for a 11KV source,
10KV will be on the 1nf cap and 1KV will be on hte 10nf cap.

Gerry R

 > Original poster: "Luke" <Bluu-at-cox-dot-net>
 >
 > Ok all this has me a bit confused.
 > I am STILL of the inclination that:
 > the two caps WILL NOT see the same voltage
 > if they are of DIFFERENT VALUES.
 >
 > Some are saying they will see the same voltage.
 >
 > What seems to be the verdict among the guys that know their stuff?
 >
 > Luke Galyan
 > Bluu-at-cox-dot-net
 >
 >