RE: Fried Caps? (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Fri, 26 Oct 2007 12:37:32 -0500
From: Terry Oxandale <Toxandale@xxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: RE: Fried Caps? (fwd)

I've used these caps successfully for hours. Mine were the same style,
but were larger at .1 uF each using 12 per string. 

I used 4 strings out of the 6 available strings in the photo link below.
I simply snap the string into place if I need a replacement or to add or
subtract capacitance (8.3 nF each). So far I've never had to replace a
"tube".

http://fototime.com/16F5B3FD17CFD95/standard.jpg

Terry



-----Original Message-----
From: Tesla list [mailto:tesla@xxxxxxxxxx] 
Sent: Friday, October 26, 2007 10:11 AM
To: tesla@xxxxxxxxxx
Subject: Re: Fried Caps? (fwd)


---------- Forwarded message ----------
Date: Fri, 26 Oct 2007 12:01:23 +0100
From: Mike Tucknott <michael.tucknott@xxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Fried Caps? (fwd)

Hi Victor

Looks like a case of cap over voltage, a few things you might like to
try is
to keep
all the strings of caps the same distance apart also most MMC banks use
a
10meg Ohm
bleed resistor across each cap this help to stablize the voltage across
each
one.

I think Terry might be able to help, I`m not to sure about the type of
caps
you are using.

If it's OK with you I'd love to add your burned and dead cap picture to
our
web site.

Cheers Mike Tucknott

>
>  Hi,
>
>   I have a pretty basic TC that I built
> a couple of years ago.  It worked great
> in the beginning but I am having issues
> with the Tank Cap.  Here are the
> design parameters:
>
> NST 12Kv, 30mA
> Spark Gap: copper tube-based, 9 gaps with @20 mils/gap
> Tank Capacitor: 77x GE 42L 3kv, (7 strings of 11 caps) (.0066 uF
total)
> Secondary Coil - 3.25" diameter, 801 turns 24 awg wire
> Top Load: 4.5" diameter aluminum ducting. total dia = 15"
>
> The problem I am having is that random capacitors just seem
> to heat up, melt, and/or catch on fire (lovely show, pic
> attached)
>
> Should I reduce my gap?  I thought that a 12kv
> input with 33kv for each cap string would be enough of
> a safety factor.  Is there some minimum spacing
> I should keep between the adjacent capacitors and/or
> the caps in the next string?
>
> Victor
>
>
>
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