Re: Current Limiting and Impedence

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Dr. Resonance" <resonance@xxxxxxxxxx>




145-160 turns will work well with a pig.  It will give you approximately
140-150 mH which is the inductance required to limit your current in the 30
amp range with a 3 x 4 inch cross section of Supercil C-10.  Works good with
a .05 to .06 uF capacitance value.

Dr. Resonance


>
> I dont think the 160 turn ballast would Saturate ,as long as I have a
'gap'
> ,  I really, really appreciate your help/ideas, but, all this math is
> WAY  over my head ,....the original 150-160 turn idea came from a man that
> makes transformers/inductors for a buisness , ...he said to keep the turns
> down a bit , or , it may saturate,.... heck, I dont know !!  Lots of turns
> , BIG air gap , Few turns, Smaller air gap,.....Brett , at Precision
> Transformer in Ft C helped me out when I went up there to pick up my #12
> wire ,....493-9094, (2506 Zuric Dr #5 )............
>
>
>
>  >From: "Tesla list" <tesla@xxxxxxxxxx>
>  >To: tesla@xxxxxxxxxx
>  >Subject: Re: Current Limiting and Impedence
>  >Date: Thu, 12 May 2005 10:28:10 -0600
>  >
>  >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 !!!!
>  >>
>  >>
>  >
>  >
>  >
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