Re: good MMC? (different than first)

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Terry Fritz" <twftesla-at-uswest-dot-net>

Hi Jonathon,

If you put the two caps in series, the value of the capcitance would divide in
half for 500pF.  The voltage would either still be 1000V or "maybe" 2000V.  I
would recomend a book from the library about electronic circuits to fill in the
details.  It is all just sort of hard to explain in e-mail land...  However,
there are some good websites too that others may suggest for basic electronic
stuff.

http://home.earthlink-dot-net/~electronxlc/

is a good site but I don't think it hits this question.

Basically, if the caps are all the same value, when they are put in series, the
total value is the capacitance of a single cap divided by the number of caps in
the string.  When they are in parrallel, the values simply add together.

The problem with the voltage is that under certain conditions the caps may
charge unequally.  Who's to say you could not charge both caps to 1000 volts
but one is at 2000 volts and the other is at -1000 volts...  So, you have to be
a little careful putting cap in series especially at high voltages where corona
and leakage may be significant and can cause "odd" voltages on series caps. 
The trick is to put a high value resistor across them to equalize the voltages
so they will not be unbalanced.  "I" strongly recommend these resistors for MMC
caps.

Cheers,

        Terry


At 10:54 AM 3/15/2001 -0500, you wrote: 
>
> ok, now when you put, for example, 2  1000V   1000pf caps in series, you get 
> 2000V, 2000pf right? or would it be 500pf? also, what is the symbol for 
> capacitance? (like V, A...) 
>
> thanx, 
> Jonathon