Re: Math help...

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

Original poster: "Brent Turner by way of Terry Fritz <twftesla-at-qwest-dot-net>" <bturner-at-apc-dot-net>

Thanks Ed...

That's what I remember when I was learning all this stuff in college.
:-)

- brent




Tesla list wrote:
> 
> Original poster: "John H. Couture by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <couturejh-at-worldnet.att-dot-net>
> 
> -----Original Message-----
> From: Tesla list [mailto:tesla-at-pupman-dot-com]
> Sent: Tuesday, July 10, 2001 5:55 PM
> To: tesla-at-pupman-dot-com
> Subject: Re: Math help...
> 
> Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <evp-at-pacbell-dot-net>
> 
> Tesla list wrote:
> >
> > Original poster: "John H. Couture by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <couturejh-at-worldnet.att-dot-net>
> >
> > Bert -
> >
> > I agree with your excellent comments below, however, I believe it should
> be
> > pointed out that the energy transfer in all magnetic circuits is 100%
> > because there are no losses in magnetic circuits. Electric losses are only
> > in electric circuits and the efficiency is the ratio of output/input.
> 
>         Oops!  There are PLENTY of losses in a magnetic circuit excited by AC
> and operating anywhere near (say 50%) of the maximum flux density.  Two
> kinds of losses.  Eddy current losses result from voltage being induced
> in the core (just like in a shorted turn)  thin sheets of steel help
> this, as does use of high resistivity steel.  Second, there is
> hysteresis loss which is caused by the fact that the magnetization and
> demagnetization curves aren't the same.  Work has to be done to change
> the direction of the magnetic field in the core.  Hysteresis loss gets
> worse as the saturation flux density is approached, and usually sets the
> limit on the design.
> 
>         If magnetic circuits were lossless transformers wouldn't warm up
under
> no load conditions.
> 
> Ed
> 
> -----------------------------
> 
> Ed -
> 
> My understanding is that with electric circuits currents flow in conductors
> and resistance (ohms) create the losses. With magnetic circuits flux flows
> in steel because of electromotive force and there are no flux losses. Eddy
> currents flow in conductors and are electric circuit resistive losses.
> Hysteresis is another matter but not involved with Tesla coils. Is this
> incorrect?
> 
> John Couture
> 
> ---------------------------