Re: Charging Inductor Construction (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Fri, 26 Oct 2007 10:29:24 +0200
From: Kurt Schraner <k.schraner@xxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Charging Inductor Construction (fwd)

Hi Crispy,

for 50mH you might do it with an "air-core" inductor, composed of a number 
of "pies" as seen for my induction coils on:

http://home.datacomm.ch/k.schraner/induc_build.htm

An example (well, I'm im metric land ;-)):
10 pies as follows
- wire: double coated magnet wire, i.e. Nexan 0.5mm/0.566mm(insulated) dia.
- inner diameter of winding:  30mm diameter
- outer diameter of winding: ~46mm diameter
- winding length of one pie:  10mm
- assumend length, including former: 13mm
- number of turns per "pie": ~250

With 10 pies you'd have 2kV per pie, which is easily supported by the 
windings. You might support the insulation even more, by impregnating the 
windings in paraffin. The windings can be made by "wild winding". Main 
problem is to obtain the winding forms. Mine are made from cardboard, 
impregnated in paraffin. Connection of the coils is in a zig-gag way: outer 
turn of one pie goes to the innermost turn of the next (_between_ the 2 
winding forms). Taps between the pies may enable different inductances.

I can send you an Excel, in order to do calculations, to meet your 
specifics. This however is in german language, and might need you to consult 
a dictionary.

Best regards,  Kurt

Tesla list wrote:
> ---------- Forwarded message ----------
> Date: Wed, 24 Oct 2007 21:52:14 -0500
> From: Crispy <crispy@xxxxxxxxxxx>
> To: tesla@xxxxxxxxxx
> Subject: Charging Inductor Construction
>
> Hello,
>
> I've been working on the pulsed DTSG coil, and have finished the spark
> gap, tank capacitor, de-Qing diode, and power supply.  The next thing
> to make is the charging inductor, but I'm not sure what the best way
> to do it is.  I need an inductor of anywhere between 25mH and 50mH
> that is able to withstand 20kV across the terminals.  Single-layer
> air core inductors of that value would have to be pretty big, and
> multilayer inductors could arc between the layers.  Does anyone have
> any suggestions on how to do this easily?  Also, if there are suitable
> inductors which I can purchase, that works just as well.
>
> Thanks,
> Crispy