SV: Re: [sdiy] Simulating SW?

[James Patchell]

I have never used the FFT feature.  I generally avoid them because there 
are a lot of variables that need to be considered.  This is probably a good 
question to be answered by the more mathematically inclined people on the 
list (hint..hint...Magnus...:-)

At 10:20 PM 11/18/2005 +0100, karl dalen wrote:
>Thanks for the spice sugestion Jim!
>I downloaded it and now trying to use it properly!:)
>
>However i havent simulated before!
>(oh, that was a bad one) :)
>
>When i run the FFT on a single sine wave i get spurious harmonics, first harmo
>are displayed 60db below fundamental
>and so on.
>
>Is this due to the number of samples in the AC sine
>model or the number of FFT points or what?
>
>The more FFT sample points i use the worser the result gets!
>Im used to get one spike in the diagram showing the fundamental
>and spurious noise a 140db below! And no harmonics!!
>
>And the signal floor are constantly changing due
>to number of FFT sample points set? Really wierd!
>
>KD
>
>--- James Patchell <patchell at cox.net> skrev:
>
> > I use the Linear Technology Switcher Cad...they promote it as a way to
> > simulate switching power supplies, but you can use it as a general purpose
> > SPICE as well...and the best thing...it is free....there are similar
> > packages available from other vendors as well...I think TI also has
> > one.  Take your pick...use the one that works for you.
> >
> > http://www.linear.com/company/software.jsp
> >
> >
> > At 07:55 AM 11/18/2005 +0000, tom.adam at telenet.be wrote:
> > >What simulation software you guys use for trying out new idea's?
> > >Or is this "not done".....
> > >
> > >Looking for a lite version, preferably freeware ;-)
> > >
> > >Cheers,
> > >
> > >--
> > >Tom Adam
> > >The Big Ear
> > >http://users.pandora.be/the-big-ear/
> > >Check out the download section!
> >
> >          -Jim
> > ***************************************************************
> > http://www.oldcrows.net/~patchell
> >
> > ***************************************************************
> >
> >
> >

         -Jim
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http://www.oldcrows.net/~patchell

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