On Sun, 2008-05-18 at 23:59 -0700, David Griffith wrote: > On Sun, 18 May 2008, Mark Lorenz wrote: > > > First, Werner, thanks for helping me get a working diode model in place. > > The link you provided was also quite helpful. > > > > Now I'm struggling with transformers, I understand that ngSpice doesn't > > support them natively, buy geda-symbols did come with a transformer symbol. > > So the question is, how do I tell what values this model takes, and what > > order then go get entered into gschem? This information would be really > > helpful for any model that one isn't familiar with. > > Ugh! I'm trying to learn how to use spice and now I learn this about > transformers. Anyone have any suggestions for designing high voltage > power supplies?
Spice can do coupled inductors, or you can use a construct with voltage sources / current sources to model an ideal transformer. You could add an inductor to model magnetising reactance, and a parallel resistor to represent core losses. However: If you want to model non-linear effects such as saturation / magnetic hysteresis, then you will need to implement a sub-circuit which implements the behaviours of the core. Take a look at search results for "Jiles Atherton spice". A colleague of mine has implemented this in P-Spice for modelling of HF lighting ballasts, but I don't know of any ngspice / spice 3 compatible implementation. Kind regards, -- Peter Clifton Electrical Engineering Division, Engineering Department, University of Cambridge, 9, JJ Thomson Avenue, Cambridge CB3 0FA Tel: +44 (0)7729 980173 - (No signal in the lab!) _______________________________________________ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user