Re: Awesome Quarter Shrinking Capacitors on EBAY

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

Original poster: John <fireba8104-at-yahoo-dot-com> 

Hi Bert,
In about a week or two I'm going to get a new multimeter with the 
capacitance measurement function, so I will measure it and end this feud 
once and for all. Also I'm going to see if I can crush a can with it (if I 
get around to it). Everyone just be patient
Cheers,
John


Tesla list <tesla-at-pupman-dot-com> wrote:
Original poster: Bert Hickman

John,

You might want to measure it with a Capacitance meter. Or, time how long
it takes to charge and then back figure the C based on the charging
current. O charge it up and discharge it through a suitable power resistor
and calculate the RC time constant to find C. Since the cap is rated for
4000 VAC, it might have been used in industrial induction heating or as
part of a mercury or sodium vapor ballast (quite likely). Does it look
similar to the LK series from Plastic Capacitors? See:
http://www.plasticcapacitors-dot-com/typelk.html

Here's the reality - Based on the physical size it's definitely a 4 uF
capacitor. With a 4000 VAC rating, your cap can withstand at least 5600
VDC. If the capacity was indeed 4,000 uF, the cap would have an energy
storage capability ! of almost 64,000 joules. Capacitor technology has simply
not evolved to the point where you can pack this level of electrostatic
energy density in a package the size of a Simpson meter.

BTW, the disruptive discharge from a 4 uF 4,000 volt cap does make one HECK
of a bang. A 10,000 joule discharge sounds more like a stick of dynamite
going off. Although your cap may "only" store 64 joules, it can kill you
just as dead as a 10,000 joule cap.

Best regards,

-- Bert --
-- 
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Tesla list wrote:
 >Original poster: John
 >HI,
 >Jim
 >It is def! initely MFD = 1E-3 Farad. This may be a custom cap, considering
 >the branch of electronics this man is in. I blow up wire and precises of
 >metal with this thing. I have to use a plate to discharge it because it
 >destroys any resistors I try to use.
 >I wish I knew where he got this cap from. If I did there is no drought I
 >would buy more.
 >I have only come up with two sources that sell similar caps 1.)
 >http://www.plasticcapacitors-dot-com and
 >2.) www.herbach-dot-com. Note: I don't think this cap
 >came from either of these sources I am only presenting them as some
 >indirect proof that caps with voltage and capacitance ratings do exist at
 >around this size. I'll see if I can post some pictures
 >Tesla list wrote:
 >Original poster: "Jim Lux"
 >Almost certainly MFD = 1E-6 Farad.. i.e. microfarad. millifarad is almost
 >ne! ver used as a unit.. microfarad, nanofarad, picofarad and micromicrofarad
 >I've seen..
 >Oil filled metal can really starts to look like 4 microfarads at 4 kV...
 >----- Original Message -----
 >From: "Tesla list"
 >To:
 >Sent: Tuesday, October 07, 2003 8:04 PM
 >Subject: Re: Awesome Quarter Shrinking Capacitors on EBAY
 >
 > > Original poster: John
msnip...