RE: Any suggestions for more spark length

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

Original poster: "Mudford, Chris" <chris.mudford-at-agresearch.co.nz> 

Hi Gerry

Yes it is pulsed DC at 100 Hz with 12.4 kV peaks unloaded.  Built much
the same as Greg Hunters example that follows.

http://hot-streamer-dot-com/greg/frames.htm

I do have a fan blowing through my spark gap but it gets damn hot, quite
quickly.

Cheers, Chris (NZ)


-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Wednesday, 29 September 2004 1:43 a.m.
To: tesla-at-pupman-dot-com
Subject: Re: Any suggestions for more spark length

Original poster: "Gerry Reynolds" <gerryreynolds-at-earthlink-dot-net>

Hi Chris,


Where is Cp at with respect to the Cres of the supply??  For a static
gap,
you might want to set Cp = 1.6 * Cres.  Also, do you have a fan for your
spark gap?

2 series MOTs and 2 series MOV???  How does the MOV voltage compare to
the
peak voltage out of the MOTs???  Doubler??  Is this a DC coil?  I think
Im
confused.


Gerry R.


  > Original poster: "Mudford, Chris" <chris.mudford-at-agresearch.co.nz>
  >
  >
  > Hi all
  >
  > I need some hints as to where my power is going?
  >
  > Coil specs are:
  >
  > Power supply:  2 series mot with doubler having 1.05 uF in each HV
leg, 2
  > series MOV diodes with by pass caps between legs and 110 ohms in each
  > output leg.  There is a safety gap to ground (CT of two transformers)
from
  > both HV outputs.
  >
  > Spark gap: 5 pipe linear satic gap (2 pipes on bottom, 3 on top,
separate
  > the top further from bottom to adjust gaps)  Total gap ~4 mm.
Parallel to
  > supply.
  >
  > Capacitor: 10 seriesed WIMA FKP1 (0.068 uF, 1600 DC, 650 AC) with 7
  > parallel strings.  33 MOHM bleeder across each cap.  Connects to
inner
turn
  > of primary and spark gap.
  >
  > Primary:  14 turns of 4.8 mm refrigeration tubing spaced at 4.8 mm as
flat
  > spiral.  35 mm space between secondary and primary inner turn.
  >
  > Secondary:  90 mm diameter wound at 540 mm length for 6:1 ratio for
1630
  > turns (0.28 mm wire, 0.32 mm including enamel).  Bottom turn of
secondary
  > ~30 mm above primary.Toroid ~90 mm above last turn of secondary (to
centre
  > of minor toroid diameter).
  >
  > Toroid:  Spun aluminium 50 x 180.
  >          Silver tape toroid 80 x 600.
  >
  > RF ground:  Short length of steel into ground which I clip to
  >
  > With the small toroid it is producing ~14".  I quickly built the
bigger
  > toroid hoping to get rid of the multiple streamers with the smaller
  > one.  But, was still getting 3-4 streamers into air at ~18".
  >
  > Things I think are poor.  SPARK GAP, TOROID, COUPLING, RF GROUND,
POWER
  > FACTOR.
  >
  > With a supply like this how does one approach power factor.  The
mains
  > supply lead is getting warm.
  >
  > Hope all you guru's can have a think about this and give me some
ideas.
  >
  > Cheers, Chris (NZ).
  >
  >