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From: DK1IS <DK1IS@kabelmail.de>
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Date: Fri, 24 Jun 2016 11:55:21 +0200
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Subject: Re: LF: RE: Re: Cumiana OOS
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Am 24.06.2016 um 10:30 schrieb DK7FC:
> Ignition coils, well, they may handle the voltage but i think the 
> winding will become to warm at 30 mA 24/7. But the main problem would 
> be that i need a certain inductance because it is a resonated circuit. 
> So i need an adjustable air gap into the ferrite material, like i have 
> in my arrangement. Also, the ignition coil may generate (and temporary 
> hold) 20 kV but i don't assume that it can generate that voltage at 
> 2.97 kHz but just on higher frequencies. It is the same with the old 
> TV transformers (LOPT). They may generate 3 kV but not at 2.97 kHz. 
> There, they would saturate. Of course i already checked that a long 
> time ago :-)
>
>
Hi Stefan,
just another idea: what about old voltage transformers 
(Spannungswandler) from your local utility company, at least for a test? 
The 20-kV-versions should have an insulation test voltage of 50 kV 
against ground and secondary winding, the nominal secondary voltage is 
100 V at 50 Hz. They have high-quality iron cores and should core-wise 
be able to handle more than 1 kW at 3 kHz. Following your own 
transductor idea, you could superimpose a DC component in series to the 
AC signal on the secondary (now primary) winding to tune the 
inductivity. Weak points could be the current capability especially of 
the primary (now secondary) windig and its resonance frequency - this 
has just to be tested.

73 es gl,
Tom, DK1IS