Re: SISG Coil question... (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Fri, 17 Aug 2007 23:50:33 +0200
From: Finn Hammer <f-h@xxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: SISG Coil question... (fwd)



Tesla list skrev:
> ---------- Forwarded message ----------
> Date: Fri, 17 Aug 2007 10:52:45 -0400
> From: Daniel Kline <daniel_kline@xxxxxxxxxxx>
> To: Tesla list <tesla@xxxxxxxxxx>
> Subject: SISG Coil question...
> 
> Hello,
> Does the operating frequency of a Tesla-coil system using a SISG matter?
> Is there a frequency that's too low or too high?

I don`t think that there is a lower limit to the resonant frequency due 
to the sisg components. I have run as low as 40kHz.
There may well be an upper limit determined by the IGBT and the 
freewheeling diode, but I am no solid state expert, so others should 
answer that.
> 
> 
> Is it possible to over-current a SISG?

Absolutely. This is determined by the current handling ability of the 
IGBT. When I grew tired of the 600Amps limit imposed by the 
IRG4PSH71KDPBF`s originally specified for the job, I switched over to 
the CM600HA and successfully ran them at 4.5kA
You can see one such brick doing 1,5 meters here:
http://www.youtube.com/watch?v=vK17-CoB7LE
> How do I calculate current through a SISG?

You need to calculate the surge impedance of the tank, and combined with 
the voltage, you have the current.

Z=sqrt(L/C)

I=V/Z

Hope this helps.

Cheers, Finn Hammer
> 
> Thanks,
> Dan K.
> 
> 
> 
> 
>