Stuart Brorson wrote: >>How do I specify an aribtrary ac source in gschem? For example, >>I want a current a source of e^(At)sin(Bt) where A and B are some constants. >> >>I have tried searching google, but am not sure what I should >>specifically search for. I have found that I can specify an ac source >>with an amplitude and a phase, but not how to specify a source which an >>arbitrary function of time. > > > Ummmm, what kind of arbitrary AC source are you looking for? I assume > SPICE. If so, SPICE doesn't support arbitrary source > waveforms using a single device. It gives you things like sine, PWL, > DC, and a few others which I have forgotten. Here's the SPICE > documentation on sources: > > http://newton.ex.ac.uk/teaching/CDHW/Electronics2/userguide/sec3.html#3.2 >
Thanks for the pointer. I see that we can form exp and sin sources. It took me quite some time to decipher the syntac in which the specs for exp are written. Actually, a differently phrased explanation in a text book's appendix showed me the light. I also see that the sin source is itself an exponentially decaying source! So I do not need two different sources at all to get an exponentially decaing sinusoidal. The only that remains is how do I insert a phase change. Or, special case, how do I get a cosine source. thanks, ->HS
