# Re: Caps in series

```In a message dated 7/1/99 8:27:19 AM Mid-Atlantic Daylight Time,
tesla-at-pupman-dot-com writes:

<< Subj:	Caps in series
Date:	7/1/99 8:27:19 AM Mid-Atlantic Daylight Time
From:	tesla-at-pupman-dot-com (Tesla List)
To:	tesla-at-pupman-dot-com

Original Poster: Erthwin-at-aol-dot-com

I know that if I wire two 5Kv .01uF capacitors in series I'll end up with a
10Kv .005uF cap but what happens when I put in a third capacitor that has
the
same ratings? does the uF rating drop by half again (15Kv .0025) or is it
1/3
of the original rating now (15Kv .00333~)...or is there a completely
different set of equations for finding this out? I ask this because I'm
planning on looking for some smaller voltage caps to wire in series and from
the other visits I've made to my local surplus I doubt I'll find anything
close to what I actually need so I might end up wiring a LOT of caps in
parallel and in series to get the values I'm looking for.

Left, left I hadda good brain but it left...
---Daniel
Dan,
You have it right. Caps in series are like resistors in parallel. Try the sum
of reciprocals method: the total capacitance = the reciprocal of the
reciprocal of C1 + C2 + C3 + C4 .........

1 / Ct = 1 / C1 + 1 / C2 + 1 / C3 + 1 / C4 .......

The total voltage across the string equals the sum of the individual voltages.
For two caps in series you can use   C1 X C2 over C1 + C2.

Cheers,
Ralph Zekelman

```