Bingo! Thanks Jinx, this is just the sort of info I was looking for. I
glanced at it, but I'm too tired to make anything of it right now, so
it'll have to wait until tomorrow.

Since I'm not an EE, nor do I even pretend to be, a few questions do
spring to mind (boing!). Is the torroid that they are talking about used
to "focus" or "enhance" the already present magnetic field, thereby
making it easier to sense using the hall effect sensor? And why does
there need to be wire wrapped around the torroid?

Please keep in mind I only glanced at the document, and that glance is
the sum total of my knowledge in this area.

Thanks!

Josh
--
A common mistake that people make when trying to design something
completely foolproof is to underestimate the ingenuity of complete
fools.
        -Douglas Adams

Jinx wrote:
>
> Hall Effect application guide (880kB)
>
> http://www.allegromicro.com/techpub2/an/an27701.pdf
>
> An example on Page 29 of a 1000A current sensor

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.