Xuircit

A desktop GUI application for drawing electrical, electronic, and power electronics circuit schematics.

Features

• Visual drag-and-drop drawing — pick components from a categorized palette and place them on a zoomable, pannable canvas
• SPICE netlist mode — write or import standard SPICE netlists; sync the canvas and netlist bidirectionally
• Full component library — Resistors, Capacitors, Inductors, Transformers, Voltage/Current Sources, Dependent Sources (VCVS/CCCS/VCCS/CCVS), Diodes, Zener Diodes, BJTs (NPN/PNP), MOSFETs (N/P), IGBTs, Ideal Switches, SCRs, TRIACs, Ground, Net Labels, Junctions
• Export — PNG, SVG, PDF schematic images; .sp/.net SPICE netlist files
• Save/load — .xcit JSON project format (human-readable, version-control friendly)

Requirements

• Python 3.10+
• PyQt6 ≥ 6.4.0

Installation

pip install -r requirements.txt

Running

python src/main.py

Project Structure

src/
  main.py                     # Entry point
  app/main_window.py          # Main window, menus, toolbars, status bar
  canvas/                     # QGraphicsScene/View canvas with zoom/pan/grid
  components/                 # Schematic symbol graphics items (QPainterPath)
  panels/                     # Palette, properties, and netlist editor docks
  dialogs/                    # Export and import dialogs
  io/                         # File I/O, SPICE parser/generator, SVG/PNG/PDF export
  models/                     # Circuit data model and component library registry

Usage

Drawing mode

1. Select a component from the left palette (double-click or press Place Selected)
2. Click on the canvas to place it; right-click to cancel
3. Press W or choose Tools → Draw Wire to connect pins
4. Hover over a component to reveal its pin dots (blue), click a pin to start a wire, click again to finish
5. Right-click a component for Rotate CW / CCW, Properties…, Delete

Netlist mode

1. Open the Netlist Editor dock at the bottom
2. Click Generate from Schematic to produce a SPICE netlist from the canvas
3. Edit the netlist directly, then click Apply to Schematic to rebuild the canvas

Keyboard shortcuts

Key	Action
Escape	Switch to Select mode
W	Switch to Wire-drawing mode
Del / Backspace	Delete selected items
Ctrl+N	New schematic
Ctrl+O	Open project
Ctrl+S	Save project
Ctrl+Z / Ctrl+Y	Undo / Redo
Ctrl++ / Ctrl+-	Zoom in / out
Ctrl+0	Fit all in view
Ctrl+Scroll	Zoom in/out
Middle-mouse drag	Pan canvas

Component Library

Category	Components
Passive	Resistor (R), Capacitor (C), Inductor (L), Transformer (T)
Sources	Voltage (V), Current (I), VCVS (E), CCCS (F), VCCS (G), CCVS (H)
Semiconductors	Diode (D), Zener (Z), NPN/PNP BJT (Q), NMOS/PMOS FET (M), IGBT
Power Electronics	Ideal Switch (SW), SCR, TRIAC
Wiring	Ground (GND), Net Label, Junction

File Formats

• .xcit — JSON project file (positions, values, connections, metadata)
• .sp / .net / .cir — SPICE netlist (compatible with LTspice, Ngspice, HSPICE)
• .png / .svg / .pdf — Exported schematic image