The Quite Universal Circuit Simulator package
Doug Reece, AK4AO, demonstrates the use of the open source QUCS (for Quite Universal Circuit Simulator) package, which can be found at http://qucs.sourceforge.net. Computer simulation software can predict the behavior of an electronic circuit. Designers can use simulations to test and refine their designs before building, and students can experiment without having to invest in parts, tools, and lab equipment.