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Re: gEDA-user: Simulation with Potentimeter
Thanks for all your replies. John your reply sounds like an interesting
thing to learn more about, but right now I have to admit it is far above
my knowledge. Does anybody here know of good tutorials on spice which
tell a litle more about topics like using models, creating models on his
own, in general the more advanced stuff. There is more and more stuff
using IC's coming up with our future lab tasks at university and I want
to be prepared for that.
Tobias
Am Mon, den 05.01.2004 schrieb John Doty um 00:05:
> Remember: dependent sources are your friends when synthesizing nonstandard
> SPICE components.
>
> Most SPICE variants give you a way to make a bilinear dependent source. In
> ngspice, for example, you can use a "B" device to make a resistor whose
> voltage is proportional to the product of the applied current (measured by
> a series "ammeter") and a control voltage. A pair of these with
> complemetary control voltages should make a voltage-controlled pot
> (although I haven't tried this particular trick).
>
> This is enormously more flexible than a swept resistor. You can sweep the
> control voltage if you wish, but you can also do a transient analysis
> using an arbitrary function for the control voltage.
>
>
> John Doty "You can't confuse me, that's my job."
> Home: jpd@w-d.org
> Work: jpd@space.mit.edu
>
> On Mon, 5 Jan 2004, John Sheahan wrote:
>
> > On Sun, Jan 04, 2004 at 09:15:55PM +0100, mailinglists@my-mail.ch wrote:
> > > Hi Stuart,
> > >
> > > I did some simulations today using ".dc name start end stepsize" so that
> > > would mean for your example
> > >
> > > Resistor sweep test circuit
> > > r1 0 1 100
> > > r2 1 2 1k
> > > v1 0 2 1v
> > > .dc r1 100 1k 100
> > > .end
> > >
> > > This way it works and generates values, but shouldn't the result be a
> > > straight line?
> > >
> > >
> > > Tobias
> >
> > this circuit has the transfer function vout = v1 . r1 / (r1+r2)
> > which is not a linear function of r1 (not a straight line)
> >
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