I use Bspice A/D Pro. http://www.beigebag.com/pricing.htm It is $350 for the full Pro version, they have a lite version for free, which is probably too wimpy for your needs but check it out anyway. You don't need the $$$ version that is bundled with Eagle if you already have Eagle or another schematic capture program. They also have a cheap competitive upgrade program. I haven't found any limitations on simulating in the pro version, it is stable, and can simulate lots of signals, analog and digital. While not the cheapest package around, it is rock solid stable and professional. Also integrates with Eagle, you can export schematics and so on. Has a large library of parts so you don't have to do any monkey wrenching to get a model to work. Exports data to a text file for further processing in Excel etc. I have only one complaint - it will measure and calculate math on all kinds of signals, but it won't calculate RMS, so I often export data to Excel when I want that feature. Other than that it is very satisfactory. There are plenty of free or GNU Spice simulators out there, but I am not familiar with any that have a graphical interface and don't require a lot of monkey-wrencking to get them to work. I am sure someone will now post a link to a totally free, stable and bugless graphical interface Spice engine which has a large and robust library, automatically creates schematics by telepathy, simulates an entire IBM mainframe with one mouseclick and runs on a PIC12C508, but I am not familiar with such things ;-) -- Lawrence Lile Senior Project Engineer Toastmaster, Inc. Division of Salton, Inc. 573-446-5661 voice 573-446-5676 fax Chris Loiacono Sent by: pic microcontroller discussion list 04/03/2003 07:57 AM Please respond to pic microcontroller discussion list To: PICLIST@MITVMA.MIT.EDU cc: Subject: To Simulate, or not to simulate? That is the Q? Does anyone know of affordable simulation software that will let me sim polyphase AC and DC circuits at the same time. I want to be able to see the polyphase relationships when the circuit is manipulated by logic outputs at various points on the time axis. I have never used a simulator, so I am basically lost as to where to even start looking... TIA, Chris -- 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 -- 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