Re: secondary core other than air

["Ivica Pauk" <ipauk-at-optusnet-dot-com.au> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

I'm new here and I still didn't build one of Tesla coils,(I intend to) but I
believe that efficiency of  primary coil can be improved simply by employing
multiturn  parallel coil instead of pancake coil,and yes there is some
materials that can be used apart from ferrite(I'm using them every day in
induction heating processes)
They are Electrolytic iron based and there is two type of alloys
one for higher frequencies(50-450kHz) and others for lower
frequencies(50Hz-50kHz)
Try search under Fluxtroll,or Alphaflux &Alphaform
Using this materials on the outside  of single turn induction coil it's
efficiency is improved by 25%.
This material can also be used with pancake coil .If it is used on one side
it will push the field on to the
opposite side off coil.It is not conductive but there is down side -it is
very expensive.Block 1"x1"x4" costs more than $100.00.
Ivan







-----Original Message-----
From: Tesla list <tesla-at-pupman-dot-com>
To: tesla-at-pupman-dot-com <tesla-at-pupman-dot-com>
Date: Tuesday, August 08, 2000 2:20 AM
Subject: Re: secondary core other than air


>Original poster: FutureT-at-aol-dot-com
>
>In a message dated 8/6/00 2:52:27 PM Pacific Daylight Time,
tesla-at-pupman-dot-com
>writes:
>
>> Original poster: "Garth van Sittert" <garth-at-mediasupplies.co.za>
>>
>>  Would it be possible to use something other than an air core to increase
>the
>>  secondary inductance and Q factor?
>
>Garth,
>
>I don't think there's any practical way to increase the inductance
>very much.  Some folks (including myself) have inserted ferrite
>rods into the secondary to increase the inductance, but it doesn't
>make a large difference, and I never use it anymore.
>>
>>  Are their any possible cores available?  I know something like ferrite
core
>>  would create internal arcs, but surely there must be something out
there!
>>
>>  I have just wound my 6.4" secondary with what I was told to be #24 wire,
>> but
>>  wintesla seems to use incorrect figures for wire guage and turns per
inch.
>
>> My
>>  secondary has 33 turns/inch.
>>
>>  My secondary inductance is way too low and I now have re-calculated my
>> primary
>>  with only 5 turns which I think will be terrible for spark gap losses.
>
>Well, many TC's have been built using a 5 or 4 turn secondary and
>good results have been obtained.  Perhaps not the best.... but good.
>
>Cheers,
>John Freau
>
> > My
>>  topload is 20" wide so I can't drop secondary resonance any more unless
I
>> use
>>  some secondary core other than air or wind more turns on the secondary.
>>
>
>
>