Re: Current Limiting and Impedence

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "david baehr" <dfb25@xxxxxxxxxxx>


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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