Re: Awesome Quarter Shrinking Capacitors on EBAY

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

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

At 03:50 PM 10/3/2003 -0600, you wrote:
>Original poster: Yurtle Turtle <yurtle_t-at-yahoo-dot-com>
>But considering that I got two 10/100 Maxwell's for a
>total of 10 kJ for less than one of his, I'd have to
>stick with my comment. I've seen bargains better than
>I got as well.
>
>http://www.hot-streamer-dot-com/adam/garage/100_mF_10kV_Maxwells1.jpg
>
>http://www.hot-streamer-dot-com/adam/garage/100_mF_10kV_Maxwells2.jpg
>
>Adam
>
>--- Tesla list <tesla-at-pupman-dot-com> wrote:
> > Original poster: dhmccauley-at-spacecatlighting-dot-com
> >
> > Thats a bargain considering you are getting a
> > capacitor which can withstand
> > repeated discharges such as those found in a quarter
> > shrinker.
> > New, these capacitors are probably upwards of
> > $10,000 each.
> >

Unless prices have changed dramatically in recent history, $10K would be 
very expensive.. Ball park figures are typically around $200-500/kJ.  Real 
high voltage (>60kV) or real high current (>100kA) would cost more, mostly 
because of different packaging required.

Surplus capacitors like this, of uncertain provenance, from catalog dealers 
(e.g. C&H sales) run a few hundred dollars at most.  For instance, 
Alltronics (up in the Bay Area) has some Aerovox PX15QD58 caps 7.14 uF-at-50kV 
for $295 each.  That's 9kJ. The picture looks like it's a bit ratty (like 
it's been sitting on a wooden pallet or wrapped in plastic. A Sangamo 14 uF 
20kV unit for $250 ( I have one exactly like this, although in a bit better 
condition, and yes, one can shrink a quarter with it)

Surplus Sales of Nebraska carries a bunch of these kind of things, but the 
prices are higher for the new parts: 28 uF -at- 30 kV 12kJ is $1400, 16 uF 
10kV is 800 J for $700... so it looks like their pricing is about $100/kJ.. 
One of their better deals is the 225uF, 15 kV unit for $800  25kJ for about 
$31/kJ

The used ones from Surplus Sales are much cheaper, but are for 
inconveniently high voltages.. 2.8 uF -at- 60 kV  5kJ for $350..

However, if you wanted to build a serious Marx, these might be the hot 
ticket.. The 1.9 uF 60 kV could be doubled for 120kV stage voltage.  16 of 
them would get you almost a megavolt at 50 kJ for only $4K in capacitors...