Date   : Mon, 13 Mar 2006 00:31:07 GMT
From   : Pete Turnbull <pete@...>
Subject: Re: Them pesky case stickers (was 1MHZ SCSI/ATA board.)

On Mar 12 2006, 15:15, Jonathan Graham Harston wrote:
> Pete Turnbull <pete@...> wrote:
> > the rotating disk.  You can also use a clamp meter, a device with a
> > ring-shaped clam on the end instead of cables.  It uses magnetic
fields
> > to measure the current, usually via a Hall effect sensor.  Many are
>
> I'm sure they work by transformer effect. The power cable is a
> single loop primary, and the ring clamp forms the secondary.

All the modern reasonably sensitive ones use a Hall effect sensor in
the clamp.  I know because I've just some some time and energy
evaluating several of them.

-- 
Pete                                           Peter Turnbull
                                               Network Manager
                                               University of York