Re: low profile caps

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

Original poster: "Jason by way of Terry Fritz <teslalist-at-qwest-dot-net>" <jasonp-at-btinternet-dot-com>

James,

These capacitors would be completely unsuitible, and here's why:

1) Their voltage rating is far too low for TC applications. At 5V apiece you
would need thousands of them to make a capacitor that would withstand the
typical 30kV spikes in a TC primary circuit.

2) They are not pulse rated. These capacitors are not designed to supply and
recieve high currnet high voltage pulses at several hundred thousand times
per second. Provided you could connect up enough to get the correct voltage
rating, they would be destroyed almost instantly if you were to pull a 1kA
pulse from them.

3) They are electrolytic. This means that they can only be used in DC
circuits, where the current flows in a single direction. In a HF AC circuit,
they would not function.

4) The capacitance is too high. If one were to build an RLC circuit with
these capacitors the Fres would be too low for most homebuilt TCs.

Capacitors suitible for TC use come in a number of flavours. A saltwater
capacitor (typically 5-15 bud bottles) will give you a capacitance of anout
1.4nF per bottle, which is enough to run most TCs up to about 500W, although
larger SW caps have been made. (Greg :) Your next, and proabably your best
option is to use MMCs, which are combiations of small commercial caps linked
together to make one larger cap with the correct rating. These are arguably
the most effiicient and the cheapest, at about $2 each. Your third option is
to buy a single pulse rated cap, for example the large white maxwell
'bricks' that many people use on much larger TCs (5kW<). Some people still
build their own caps out of poly sheet and heavy duty foil, but they are
messy, difficult to construct and prone to failure.

Best of luck,
Jason

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Wednesday, January 08, 2003 3:14 PM
Subject: low profile caps


 > Original poster: "james brady by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<james_brady10-at-hotmail-dot-com>
 >
 >
 >
 >
 > Hey,
 >
 > I saw an advertisement in a magazine, for this company that sells low
 > profile capacitors. They say that they sell them  from 0.1 to 10 farads!
 > Ok, I know that I am new at this, but wouldn't buying a 10 farad capacitor
 > be better than making a saltwater capacitor?
 >
 >
 >
 > www.cooperet-dot-com/pdfs_html/powerstorf_specs.pdf
 >
 >
 >
 >