Re: Current Limiting and Impedence

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Gerald  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>

Hi David,

You can put your ballast inductor directly across your variac and plot the 
current as a function of the variac's output voltage.  and see how linear 
it is and if it saturates.  The impedance of the inductor will be Xp = 
Vp/Ip (assuming the resistance is negligable).  Choose a Vp,Ip pair for 
where you intend to operate it at.  Assuming your ballast does not 
saturate, you can transfer the primary ballast impedance to the secondary 
by multiplying it by the turns ratio squared.  Xs = Xp * N^2.  Cres can 
then be calculated as follows:

Cres (nf) = 10^9 / (2*pi*freq*Xs)

If both of your ballast configurations limit the current at 14 amps, the 
effective inductance should be the same and where you are relative to 
charging resonance will depend on your Cp.  This assumes no saturation.  If 
the 160 turn ballast saturates, its effectivce inductance will go down.

Gerry R.



> Original poster: "david baehr" <dfb25@xxxxxxxxxxx>
>
>
>
> Ok, I had trouble when I substituted  a static spark gap with a  SRSG , 
> would not operate correctly ,....it was suggested that my home made 
> ballast( gapped 'E' and 'I' core ) was resonating with the ballast, and,I 
> should add more turns to the ballast. Now, just say I wanted a short 
> circuit value of 14 amps , would there be a diff in resonance if  I had 
> 270 turns at 14amps , but having to remove the 'I' completly from the 'E' 
> to reach that value , or , to have 160 turns , but having the 'I' shimmed 
> about .06" to reach the 14amps Im lookin for ???  ....between these two 
> configurations , would they still have the same resonances with the cap or 
> ??,,,,,, Heck , I dont know !!!!