Re: HV Choke Design (fwd)

---------- Forwarded message ----------
Date: Sun, 18 Jan 98 16:01:17 -0500
From: Adam <absmith-at-tiac-dot-net>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: HV Choke Design (fwd)

>I used small cores which were originally commercially wound common mode
>mains suppression chokes, removed all the wire and bobbin to just leave
>the ring core. These cores are of the right material for RFI suppression
>use (Generally Mn/Zn ferrite of a high permeability). These type of
>chokes can be obtained as surplus for very little money! 

Your main enemy will be saturation.  The small cores work fine as common 
mode chokes, since the flux from 60Hz current in each winding cancels the 
flux of the other (zero net flux).  In tesla use, they are no longer 
common mode chokes, and it will take very little 60Hz current to saturate 
these small high-permeability cores.

I would only expect these chokes to function adequately on the smallest 
of coils (e.g. an OBIT powered coil)