Re: Maxwell capacitor question

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

Original poster: Tesla729-at-cs-dot-com 

In a message dated 10/13/03 11:20:08 PM Pacific Daylight Time, 
tesla-at-pupman-dot-com writes:
>Original poster: "Phil Heslin" <pheslin-at-cox-dot-net>
>
>Hi David,
>
>    I found an original spec sheet for the 31350 caps and you were right on
>with you assumptions. The specs are as follows:
>
>.1 uf +/- 10%, 100KV tested -at-105KV, 500 Joules, 20% rated voltage reversal,
>80% max voltage reversal, Peak current 25KA, rep rate 1pps, max RMS current
>25A, max operating temp 40 deg c, min 10 deg C, design life 30K full
>charge/discharge cycles, DC life 1000 hours, Inductance 20nH, non PCB
>impregnant and all the single ended plastic caps over 60KV require
>submersion to operate at those voltages.
>
>     I have often wondered if it would worth it to build a rectifier to avoid
>the voltage reversals and extend the life of the cap(s).
>
>
>            Phil


Hi Phil,

Thank you so much for finding this info for me ;^) I serached
the web to no availe for the specs on this particular capaci-
tor and I figured if anybody could help it would be someone
on the pupman list :^)) BTW, I don't recall seeing your name
on this list before, either you're a lurker or maybe I'm just
not too observant :-) Anywho, thanks a million (volts) for the
info.

I would suppose that using these caps in a 14.4 kV, 10
kVA PDT system would not be stressing them much at all,
at least not their voltage ratings. If I use both of them in parallel
(.2 uFD) that would give me a 50 amp RMS rating. I hope that
would be beefy enough on the RMS current rating.?  Jim
Lux has a webpage regarding the adjusted firing life of these
capacitors at voltages considerably less than the caps'
nameplate rating and it looks like I could run these for a
reasonable amount of time before likely failure on 14,400
VAC, even at elevated bps, assuming that they haven't
experienced too much abuse already,

As far as running a high powered coil on filtered DC, that
really complicates it. I have thought of that myself in the
past but when I considered how huge of a  filter cap that
you would need to properly filter 10 kW worth of 15 to 20
kV from single phase AC (multiple uFDs),the inductive ballasting
and the extreme danger of the stored energy of the filter cap, plus
the co$t, I figured that it was safer and a whole lot simpler and
cheaper to stick with AC. I'm pretty sure that there are a few list
members that have gone the DC route on high powered coils
though and I'm sure that they could make qualified comments
regarding this.

David Rieben