Re: eddy current

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

Original poster: davep <davep-at-quik-dot-com> 


>Can anyone point me in the direction (and not google either! ) to find a 
>good article to explain eddy current.

         Any good electrical engineering text.
         Or it can be found by googling.
         Usual discussions will concentrate on effects other
         than skin effects.

> From what I can gather it is the force which make the current flow

>towards the outside of the wire (skin effect).

         That's a particular case.
         Roughly:
         Any changing electrical current will have an accompanying
         changing magnetic field.
         If there is a conductor in this magnetic field (say:
         a transformer core...) the changing mag field will induce
         electrical currents in the 'conductor'.  These will heat
         the conductor, the heating energy is lost.  These are
         called 'eddy currents' because they flow in closed
         loops in the 'conductors', like 'eddies' in water.
         Eddy currents are reduced by choice of materials, shaping
         of cores, etc.


>It would be interesting to do some experiments on this. Would it be 
>possible to make 2 coils one with a high eddy current loss and one without 
>for exepriments and testing ?
         Its been done.  Others can better cite specifics.  Some

         of the effects are 'nonobvious'.  Low eddy current loses are
         a good thing.

-- 
         best
         dwp

...the net of a million lies...
         Vernor Vinge
There are Many Web Sites which Say Many Things.
         -me
...for he has read everything, and written nothing...
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