Re: Rebuilding an OBIT

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-uswest-dot-net>" <evp-at-pacbell-dot-net>

Tesla list wrote:
> 
> Original poster: "S.Gaeta by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<sgtporky-at-prodigy-dot-net>
> 
> Hi All,
> 
> I have a 10KV, 23mA OBIT that burned out in furnace duty last Winter. I
> finally got around to depotting it and found that the only part of the
> secondary that was any good is the bobbin. I am in the process of rewinding
> it with 34 AWG wire (much thicker than what was on there before!). I am
> designing it to give me about 5KV total. I chose the 34 AWG because it looks
> like the same diameter wire that they used on a 12/60 that I also depotted.
> My goal is to get 60mA out of this thing.
> My question is: How much current can I get out of this thing before the core
> saturates and gives me grief. 

	Current doesn't saturate cores, voltage does!  You'll need the same
number of turns on the primary that you had before.  If you destroyed
the primary, a conservative rule of thumb is that the number of turns is
the voltage divided by the cross sectional area of the core in square
inches.

<A lot of folks have written about knocking
> shunts out of NSTs, but has any one else ever tinkered with OBIT cores?
> 
> Thanks,
> Sue

Ed