Re: tesla virgin no more ! but need help

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

Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com> 


No, you need 2 strings in parallel to get the 17.6 nF required.

Dr. Resonance

 >  >
 >  > .15 uF / 17 caps per string = .0088 uF per string x 2 strings in
parallel = .0176 uF =
 >  > 17.6 nF bank total capacitance
 >  >
 >  >
 >  > Your .02 uF rating would be extreme even for a synchro RSG type
sparkgap
 > and
 >  > way to large for a stationary sparkgap.
 >  >
 >  >
 >  > Dr. Resonance
 >  >
 >  > Resonance Research Corporation
 >  > E11870 Shadylane Rd.
 >  > Baraboo   WI   53913
 >  >  >
 >  >  > My caps are Cornell 942C16P15k   rated -at-.15uf 1600VDC . I figured on
a
 >  > total
 >  >  > capacitance
 >  >  > of around .02 uf , why am i way off here?
 >  >  > I have a safety gap set a hair over firing gap space about .28".
What I
 >  >  > don't understand is if ..02uf is way overkill for a 15/30 with a
static
 >  > gap
 >  >  > why does the coil operate with my 9/30,
 >  >  > I would like to properly match MMC size and Gap size for this 4"
coil
 >  > based
 >  >  > on  some recommendations
 >  >  >
 >  >  > I have not blown any other caps since then
 >  >  > when I apply power to the coil  with  a 15/30
 >  >  > the gap fires briefly the coil functions for 1-5 seconds and then
 > stops.
 >  >  >
 >  >  > Steve
 >  >  >
 >  >  > Steve
 >  >  >
 >  >  >
 >  >  > Message -----
 >  >  > From: "Tesla list" <tesla-at-pupman-dot-com>
 >  >  > To: <tesla-at-pupman-dot-com>
 >  >  > Sent: Thursday, February 05, 2004 10:12 AM
 >  >  > Subject: Re: tesla virgin no more ! but need help
 >  >  >
 >  >  >
 >  >  >  > Original poster: Mark Broker <mbroker-at-thegeekgroup-dot-org>
 >  >  >  >
 >  >  >  > Congrats on first light!
 >  >  >  >
 >  >  >  > .025uF is *way* too much cap for a 15/30!  You want more like
.008uF
 >  > for a
 >  >  >  > static gap and a 15/30.  Did you retun when you removed
capacitors?
 >  > Are
 >  >  >  > you using a Safety Spark Gap?  Did you set it properly before
 >  >  >  > operation?  What type of MMC cap are you using?  Brand and model
 > will
 >  > be
 >  >  >  > great, or just type of dielectric will suffice.  Where on the
caps
 > are
 >  > the
 >  >  >  > holes/failures located?
 >  >  >  >
 >  >  >  > My first MMC used 11 caps per string of 1600VDC caps.  No
problems
 >  > there
 >  >  >  > despite shorting the MOVs in a "Terry Filter...."
 >  >  >  >
 >  >  >  > So I, too, think that your MMC is probably suspect.  Answers to
 > these
 >  >  >  > questions will help us determine what's going on.
 >  >  >  >
 >  >  >  > Cheers,
 >  >  >  >
 >  >  >  > Mark Broker
 >  >  >  > Chief Engineer, The Geek Group
 >  >  >  >
 >  >  >  >
 >  >  >  > On Wed, 04 Feb 2004 18:07:59 -0700, Tesla list <tesla-at-pupman-dot-com>
 >  > wrote:
 >  >  >  >
 >  >  >  > >Original poster: "steven hyman" <steve502-at-bellsouth-dot-net> I have
 > been
 >  >  >  > >building my first coil (Researched this lists archives for over
a
 >  > month
 >  >  >  > >,along with all the websites Thanks), and had first sparks
 >  >  >  > >on Saturday  WOW!!!, about  15 inches, but having some problems,
I
 >  > cannot
 >  >  >  > >figure out, and need some expert advise
 >  >  >  > >
 >  >  >  > >     Spark gap , static type with 6 ,1" diameter x2" long copper
 > pipes
 >  >  >  > > laid out flat, gap spacing about 1mm  with fan
 >  >  >  > >.  MMC with 2 strings 12 each string(24total of 1600kv .15uf
 >  > poly's.Total
 >  >  >  > >value .025 uf ??? ( can someone check this)
 >  >  >  > >      I am presently powering this coil with 15/30 NST
 >  >  >  > >
 >  >  >  > >first light was great, ran the coil 10-15 short runs 12-24 inch
 >  >  >  > >sparks.   Then the  spark gap would only fire for about a second
 > and
 >  >  > stop,
 >  >  >  > >after inspecting the MMC realized I had burned 2 caps up ( big
 > holes
 >  > in
 >  >  >  > >two caps together in series), I replaced these caps, and added 3
 > more
 >  > per
 >  >  >  > >string( now qty 15- .15uf 1600kv each per string x 2 strings))
but
 >  > same
 >  >  >  > >problem, after some evals, my present  situation remains the
same ,
 > if
 >  > I
 >  >  >  > >remove the parallel connection between the 2 strings of 15 caps,
 > and
 >  > use
 >  >  >  > >each string alone, the gap fires ( but no sparks from top
load( I
 > can
 >  > get
 >  >  >  > >spark from topload with breakout), but if I reconnect the 2
strings
 > of
 >  >  >  > >caps , same problem, gap only fires for about a second or two,
and
 >  >  >  > >nothing, I have tried the coil using a smaller NST (9/30 )   and
 > the
 >  > coil
 >  >  >  > >works well all components working with about 15" sparks.
 >  >  >  > >
 >  >  >  > >4" secondary 1050 turns ,24awg, 21.5 " coil length
 >  >  >  > >12 turn primary 1/4 od, 1/4 spacing( tuned at about 7 turns)
 >  >  >  > >
 >  >  >  > >I suspect the MMC  configuration, but cannot figure this out !!
I
 >  > thought
 >  >  >  > >15 x1600kv caps would suffice for a 15/30 nst (15 x 1600=24kv
 >  >  >  > >any help would be greatly appreciated
 >  >  >  > >
 >  >  >  > >Steve
 >  >  >  > >
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