Circuit Simulator

A Python DC network solver using Modified Nodal Analysis (MNA).

Overview

This project implements a modular DC circuit simulator based on Modified Nodal Analysis (MNA).
It supports arbitrary network topologies using NetworkX and allows simulation of:

• Resistors
• Voltage sources (with internal resistance)
• Ideal switches

The solver constructs and solves the MNA system matrix A x = b, then returns per-node voltages and per-component currents/voltages for inspection or debugging.

This project is designed to demonstrate engineering fundamentals in numerical methods, circuit simulation, object-oriented design, and structured testing.

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Features

• Build networks via add_node() and add_component()
• Full MNA stamping for:
  • Resistors (conductance form)
  • Voltage sources (with additional current unknowns)
  • Switches (open/closed resistance modeling)
• Automatic node indexing and isolated-node removal
• Ground selection and matrix conditioning
• Node voltage reporting
• Branch voltage & current reporting with clear sign conventions
• Physics-based validation tests (series & parallel examples)

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Example Usage

Please refer to either "examples/series_network.py" or "examples/parallel_network.py" for examples on how to build networks, and solve them.