Introduction to GEEC

What is GEEC?

GEEC (Graphic Editor of Electrical Circuits) is a web-based circuit design and simulation platform developed at Czech Technical University in Prague. It combines an intuitive graphical interface for drawing electrical circuits with powerful analysis engines for both numerical and symbolic analysis.

GEEC is ideal for:

  • Electrical Engineering Students learning circuit theory and analysis
  • Educators teaching circuit design and simulation
  • Engineers prototyping and validating circuit designs
  • Researchers exploring symbolic and numerical circuit behavior

Key Capabilities

Circuit Drawing

Create electrical circuits using an interactive canvas with:

  • Intuitive drag-and-drop component placement
  • Wire connections with automatic node management
  • Customizable component library
  • Full undo/redo functionality with project history

Multiple Analysis Engines

Choose the right tool for your analysis needs:

  • NGSpice - Industry-standard numerical circuit simulator (AC, DC, transient response)
  • SymCirc - Symbolic analysis engine for exact mathematical solutions
  • General Tools - FFT and Fourier analysis for frequency domain exploration

Rich Export Options

Export your work in multiple formats:

  • Raster formats: PNG, JPEG, WebP
  • Vector formats: PDF for high-quality printing
  • LaTeX: PDF + TeX source for academic papers
  • Netlists: SPICE format for external tools

Interactive Parameter Exploration

  • Design variables — use symbolic names (e.g. R, Cx) as component values to tune the entire circuit from one place
  • Mathematical expressions — component values can reference variables and standard math functions (e.g. 1/(2*pi*f*C))
  • Interactive sliders — a floating panel lets you drag a slider to change a variable and instantly re-run all open analyses
  • Result boxes — live displays shown directly on the canvas that update automatically whenever an analysis is re-run

Browser Requirements

GEEC is a modern web application that requires:

  • A modern web browser (Chrome, Firefox, Safari, Edge)
  • ES6+ JavaScript support
  • HTML5 Canvas API support
  • Clipboard API for copy/paste operations
  • File API for project import/export

Manual Structure

This user manual is organized into the following sections:

Getting Help

Ready to get started? Continue to Getting Started to learn how to access GEEC and create your first circuit.