Those are listed as having material type "HY 2" and they are powdered iron,
not ferrite. The characteristics of that material are given on page 2 of
this document:

http://www.jaycar.com.au/images_uploaded/ferrites.pdf

Despite the name being ferrites.pdf, it also covers powdered iron.

It looks like this would be OK as a material for SMPS inductors up to
100kHz or so. I bet, though, that if you compared it with materials
intended for SMPS use, some of the properties would fall short. For
example, compare it to 3F3 material:

http://www.ferroxcube.com/prod/assets/3f3.pdf

Note how much higher the permeability is for 3F3.

Sean



On Wed, Jul 31, 2013 at 2:02 AM, IVP <joecolquitt@clear.net.nz> wrote:

> > Unfortunately, at a quick glance, it doesn't look like any of the
> > three options you chose are really intended for SMPS applications
> > but rather EMI suppression. Depending on additional characteristics
> > which are not in the quick descriptions I saw, they may also be
> > acceptable for SMPS
>
> FWIW, I buy these powdered iron toroids, similarly described
>
>
> http://www.jaycar.co.nz/productView.asp?ID=3DLO1242&keywords=3Dtoroid&for=
m=3DKEYWORD
>
> I wind in the 50-400uH range and they seem to work well
> enough with an MC34063 at 35kHz. Going by colour alone,
> they look like (and perform like) those I've scavenged from
> commercial SMPS and re-wound. They are also specified
> by part number in various magazine constructional articles, so
> I presume the authors of those articles consider them OK for
> SMPS
>
> Joe
>
> --
> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
>
--=20
http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.