Simulating Circuits Using QUCS, the Quite Universal Circuit Simulator Doug Reece, AK4AO May 22, 2015

About QUCS Free software! Provides CAD tools for drawing schematic diagrams Simulates the behavior of the circuit represented by the schematic DC AC Frequency domain Time domain Digital logic

Uses for QUCS Students/hobbyists: Experiment with various types of electronic circuits without components and lab instruments Professionals: Analyze circuit performance before building Caution: Models don’t capture all aspects of a real circuit: stray capacitance/inductance, hum pickup, etc.

DC Circuit: Voltage Divider

Voltage Divider with Parameter Sweep

AC Circuit – Frequency Domain

AC Circuit – Time Domain

Digital Logic Simulation

Some other QUCS Features Libraries of real devices Filter design Attenuator design Equations, including differential equations Optimization

Resources URL for software (MAC, Windows, various Linux flavors, source code) http://qucs.sourceforge.net/ Note: Windows version loads several programs Tutorials: http://qucs.sourceforge.net/docs.html