I definitely need to use SPICE more often. Without practice it is time consuming, without a doubt. I was referred to a tool called PSCAD by some folks on another list, and found a free download - something done by Manitoba Hydro. It looks very interesting, but there is apparently another learning curve to get past....Hmmmm >> SPICE. But you have to learn to use it properly or it will lie to you >> all the time. > >I can't tell if you have read the full message I posted and are breaking >my chops, or if you are serious. I am not familiar with that expression. I was answering your op before reading the whole thread (I see digests, 24 hours out of phase - I should quote more of the op probably). Setting up a simulation in SPICE needs to be done once. Then you use it as a template (or subcircuit) for each new design. A couple of hints: - Three phase supplies can be made by using three sine wave ac sources, specify the phase for each (you knew that). - Phase synchronous thyristor firing points can be obtained in several ways, one being a sawtooth source (square wave + rc lowpass filter works too) that drives a voltage controlled switch (whose reference voltage is a voltage source you can set). The edge of the output from this can be used as a firing pulse after differentiation. - A real power measuring device can be built from a multiplier connected suitably across voltage and current (the latter obtained from a probe resistor and a voltage controlled voltage source with suitable gain). By using the maths built into spice you can write expressions for 3-phase power, rms, reactive power for strange waveforms from chopped ac, dc component, whatever. By saying that you need to learn to use SPICE properly I meant the not so obvious features, as described above. Since it's a simulator you can do things that are not possible in a real circuit. I assume that you are using a graphical input tool for SPICE (schematic capture). Writing it by hand may be hard ;-). -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics