[Mike Kost <mike@ta...>]

Hi there,

I've been simulating models of analog PWM modulators. I've noticed that if I
do not have a sufficient number of points per ms of simulation time, the
results will start to diverge (wildly) from the expected result. As I add
simulation points, it converges on the expected result. This is not
unreasonable since PWM systems have very large transients (depending on how
the simulator handles such transients). The downside is that I end up with
much more simulation data than is necessary for review/analysis, and qucs
gets a little chunky when it has a 1.5 GB memory footprint. I noticed that
the transient simulation has a MinStep property that expresses the minimum
time step size to be used in simulation, but that there isn't a MaxStep
property. My interpretation is that the MaxStep is defined as (Stop -
Start)/Points. If this interpretation is correct, is there a way to specify
a MaxStep equivalent that's independent of the number of data points
captured? If not, any suggestions for better accuracy with fewer points?
I've already manipulated the integration method and gotten large
improvements over the 2nd order trapezoidal (I'm on a 4th order Gear at the
moment).

Thanks,

Mike
mike@...