Re: Crushing ferrite cores to make one big one?

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

Original poster: "Malcolm Watts" <m.j.watts-at-massey.ac.nz> 

On 14 Feb 2004, at 12:01, Tesla list wrote:

 > Original poster: "Hydrogen18" <hydrogen18-at-hydrogen18-dot-com>
 >
 > I've been on the prowl for cheap transformer cores recently and
 > something just occured to me. I have TONs of ferrite cores, and they
 > are amazingly cheap to obtain in large weight. what If I just took and
 > ground them up, then say filled a 3 inch PVC pipe with them? I could
 > use this as a core for a fairly large 60 Hz transformer couldnt I? Any
 > thoughts on this somewhat crazy idea?

Not a good one. You'll have a distributed airgap built into the core
and a rather low permeability as well as plenty of scope for energy
storage. You'd be better off using it as a choke core. I did exactly
what you're suggesting years ago. In fact I have two cores stuffed
full of broken ferrite, the largest being 4.5" diameter. I forget the
induction factor.

Malcolm