New Tesla Book
Subject: New Tesla Book
From: jim.oliver-at-welcom.gen.nz (Jim Oliver)
Date: Sat, 12 Aug 1995 01:09:00 GMT
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TE>From: richard.quick-at-slug-dot-org (Richard Quick)
TE>Subject: New Tesla Book
TE>RE: HIGH VOLTAGE GENERATION WITH AIR-CORE SOLENOIDS
TE>written and published by Thomas W. Lee, 8329 E. San Salvador Dr.
TE>Scottsdale, AZ 85258 USA
TE>> outside tube keeps the winding submerged in MINERAL OIL!
TE>> (Polyurethane has it's disadvantages but...)
TE> JO> Where does the polyurethane come in Richard ?
I didn't realise until after I had replied to this that you meant
the polyurethane coatings that YOU use. I thought from the way it
read that the authour had used some PU coatings in some strange
TE>Well the whole idea of the two nested acrylic tubes and
TE>submerging the secondary winding in oil is to increase the
TE>breakdown voltage of the construction and to eliminate corona
TE>I have verified that corona losses can be reduced to acceptable
TE>levels by coating the secondary coil with enough heavy coats of
TE>polyurethane sealer that the ridges and valleys of the magnet
TE>wire winding are eliminated, followed by loading the coil with
TE>the proper sized toriod discharger.
I wonder how sulphur hexafluoride would go as an insulator :-)
TE> JO> Was there any rationale for all this complexity ?
TE>The large number of turns creates a large self capacitance in the
TE>winding that delays the current peak in the coil. The long thin
TE>wire has a high DC and RF resistance which further weakens the
TE>current peak developed in the coil. A sharp current peak in the
TE>coil is essential in obtaining a long hot spark.
That statement above higlights what I've rambling on about in
"art and science". What you say there appears to be pure
TE>Using a small sphere discharge terminal does not corona protect
TE>the secondary winding very well. As you saw in the pictures of
TE>Malcolm's coil, many good sparks, and lots of corona, will leave
Of course. He has since installed a larger toroid with MILES
TE>The author's solution for such a poorly designed coil is to
TE>engineer the problem away after the coil is wound. By sumberging
TE>the secondary in mineral oil, so that the winding has about one
TE>inch of oil all around it, excessive corona losses from the
TE>windings are reduced to nearly zero. Mineral oil prevents
TE>parasitic 1/4 wave voltage peaks from breaking out of the sides
TE>of the coil, and gives sufficient electrical strength that most
Don't we want these to break out at the top of the coil ?
TE> JO> What is the claimed performance ?
TE>it is coupled to the correct primary. This performance comes at a
TE>very high cost in materials however...
I agree. Spoken like a true coiler. If something can be lower
cost for improved performance, then we must embrace it ! My
roamings around junk yards proves it also.
Jim Oliver <jim.oliver-at-welcom.gen.nz> (3:771/370)
* SLMR 2.1a * It is easier to get forgiveness than permission.