Re: Newark ebay capacitor: primary tank capacitor?

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

Original poster: "Virtualgod" <mike.marcum-at-zoomtown-dot-com> 

Not sure. I'd be chicken to try with 2000 volts. What I usually do is put in
11.5v (on a 115v primary), measure the secondary current with that and
multiply the result by 10. Any ratio would work as long as secondary
current/voltage doesn't go over the limit of the meter (usually 10A,600v). I
don't try this with "unknown" transformers that might possibly have a 1000:1
ratio or something like that (aka:dental x-ray transformer) since my variac
goes down to 1.4v at the lowest, that would still be 1400v.

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Thursday, February 26, 2004 8:27 PM
Subject: Re: Newark ebay capacitor: primary tank capacitor?


 > Original poster: "Hydrogen18" <hydrogen18-at-hydrogen18-dot-com>
 >
 > yes, I intend to ballast the 4 pack MOT severely, I am going with it
because
 > it seems cheaper and more dependable than NSTs and I ballast it down for
 > smaller coils but still have a psu capable of handling the big ones. Can I
 > use my clamp meter to measure the secondary current?
 >
 > ----- Original Message -----
 > From: "Tesla list" <tesla-at-pupman-dot-com>
 > To: <tesla-at-pupman-dot-com>
 > Sent: Thursday, February 26, 2004 9:01 AM
 > Subject: Re: Newark ebay capacitor: primary tank capacitor?
 >
 >
 >  > Original poster: "Virtualgod" <mike.marcum-at-zoomtown-dot-com>
 >  >
 >  > The 10 kv ones? Usually doorknobs are rated dc or dc peak volts. For 4
 > mots
 >  > (~8kvac) you would need at least 24 kvdc worth. And mots put out about
 >  > 300-500 mA. Assuming 500 mA, 60hz, and a LTR static gap (probably a
rotary
 >  > would be needed with that much current), that equals .2487 uF, which
would
 >  > probably mean a single turn primary (or less, which would problem)
unless
 >  > your coil is huge. You would need 3 in series (round up to 30kv), which
 > cuts
 >  > the capacitance down to 1100pF x 226 sets these (or less, depends how
much
 >  > you limit the mot current). 678 of these would be very expensive and
would
 >  > be a major pain just to put them all together. It would take 104
(8series
 >  > x13parallel array) of the 942c's (about $260 worth). Of course it would
 > take
 >  > less if you limit the mots more.
 >  > ----- Original Message -----
 >  > From: "Tesla list" <tesla-at-pupman-dot-com>
 >  > To: <tesla-at-pupman-dot-com>
 >  > Sent: Wednesday, February 25, 2004 1:24 PM
 >  > Subject: Re: Newark ebay capacitor: primary tank capacitor?
 >  >
 >  >
 >  >  > Original poster: "Hydrogen18" <hydrogen18-at-hydrogen18-dot-com>
 >  >  >
 >  >  > Gah forgot to say, would 10 of the 3300 pf, or 3.3 nF, in paralell
be
 >  >  > suitable for a 3 inch coil with a 4 pack mot supply?
 >  >  > ----- Original Message -----
 >  >  > From: "Tesla list" <tesla-at-pupman-dot-com>
 >  >  > To: <tesla-at-pupman-dot-com>
 >  >  > Sent: Wednesday, February 25, 2004 8:27 AM
 >  >  > Subject: Re: Newark ebay capacitor: primary tank capacitor?
 >  >  >
 >  >  >
 >  >  >  > Original poster: "Virtualgod" <mike.marcum-at-zoomtown-dot-com>
 >  >  >  >
 >  >  >  > With doorknob types, it's hit or miss. The ones that are not
rated
 > for
 >  > rf
 >  >  >  > will overheat and die. Not sure if there is a way to tell just by
 > snip...........
 >
 >
 >