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Re: 1/4 wave TC (fwd)

---------- Forwarded message ----------
Date: Wed, 25 Jul 2007 16:20:20 -0500
From: Harold Weiss <hweiss@xxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: 1/4 wave TC (fwd)

Hi Skip,

Try setting your safety gaps with just the 9KV NST.  They should only fire 
with the NST on startup when you get transients.  Then hook everything to 
the primary tank circuit.  If it's still firing, then you need to adjust 
tunning and/or phase of the SRSG.

Make sure your cap voltage capacity is about 2.5 X the NST voltage.  Also 
make sure you are running pulse rated caps that are rated for more than 120 
pulses per second.  That should stop the explosions.

David E Weiss

> Hi All
> Well after my capacitor literally exploded and destroyed both the
> primary and secondary of the first 1/4 wave TC, a new one has been built
> and is in test. The specs are:
> Primary: 7 turns, 1/4" tubing, 19" in diameter
> Secondary: 390 turns #22ga, 0.050" overall diameter insulated wire, 14"
> diameter, winding len:19.5", frequency len of wire: 217khz, wire length
> 1429'
> Measured Resonance of secondary is 210 khz. no excitation
> With 5 x 20 toroid: 205khz
> With two 5 x 20 toroid: 150 khz
> Driver: 9kv x 120ma NST
> Break: SRSG with 2 poles
> Cap: .027
> Some of the test results:
> Variac set no higher than 40 or about 50 volts input
> Spark length:
> No toroid: multiple 12" (+) arcs from top turn of sec
> One toroid: 20" (+) from breakout point
> Two toroid: 27" (+) from breakout point
> Operating freq: with toroids: 140khz
> Operating freq: without toroids: 190khz
> Note that the wire length frequency and the operating frequency with no
> top load under power are pretty close. I am trying to figure out how to
> concentrate the discharges into a single streamer without a top load. I
> seem to be processing a large amount of power and the total amount of
> sparks with or without a top load seems to be similar.
> Above the "40" setting of the variac the NST safety gaps really fire
> nearly all of the time and so far I am afraid to open up the gaps which
> are set to about 0.125". Does anyone have a comment as to the maximum
> safety gap opening that I might use on a 9kv NST? It looks like this
> thing will really perform at higher inputs but I do not want to risk the
> NST yet.
> Skip