Re: Maxwell capacitor question

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

Original poster: "Jim Lux" <jimlux-at-earthlink-dot-net> 

the life only goes as the 1.5 power or something of the Q (related to the
VR)...
It goes as the 7th power of voltage... Just run them at a more conservative
voltage...

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, October 13, 2003 10:36 PM
Subject: RE: Maxwell capacitor question


 > 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
 >
 >
 >
 > Original poster: Tesla729-at-cs-dot-com
 >
 > Hi all,
 >
 > I have recently located and purchased (2) cat # 31350 100 kV,
 > 0.1 uFD Maxwell pulse caps (they're still enroute-haven't gotten
 > here yet) and was trying, with no availe, to locate some specs
 > on this particular capacitor. They are the single ended 2" x 6"
 > x 15.75" long plastic oil-filled case. I figure they're probably rated
 > for 1 pps at their rated voltage and probably 25 amps RMS and 25
 > kAmps peak per discharge -at- < 20% V reversals. I believe all
 > of the single ended 100kV rated Maxwells have to either be
 > submerged in oil or in one atmosphere of dielectric gas to operate
 > at the full rated 100 kV. Of course I will never be approaching
 > this max voltage limit for coiling so running them in open air
 > will be the way that I go.
 > Anyway, I was planning on trying to use them in my remodeled
 > 10 kVA pole pig coil. I figure they can be run at much higher bps when
 > the voltage is kept well below the max kV rating. 14.4 kVAC rms
 > would only reach about 20 kV peak (not considering resonant rise
 > of course). I was planning on parallelling them for 0.2 uFD and
 > maybe trying to go synch. They should handle 50 amps RMS in
 > this configuration but would that really be sufficientfor a pig? Of
 > course since they're used I don't know how many shots are left in
 > them and I think they are only rated at either 30K or 100K shots, at
 > the rated max voltage, at best. I have personally never had a Maxwell
 > cap fail from too many shots, though I have blown up a few lossy
 > polyester dielectric pulse caps (not Maxwells though) from over
 > current (get too hot and finally explode ;^O) but I know they do have
 > a limited "shot" life.
 >
 > As always, I value the advice from this list.....
 >
 > David Rieben
 >
 >