(a manual to the Impedance Simulator)
1. Purpose
This simulator allows you to:
- build equivalent electrical circuits
- simulate impedance spectra
- visualize results as Nyquist and Bode plots
It is intended for learning and exploring electrochemical impedance spectroscopy (EIS).
2. Circuit syntax
Circuits are entered as a text expression.
Basic rules
- – → series connection
- || → parallel connection
- parentheses () → grouping
Examples:
R-(R||C)
R0-(R1||C1)-(R2||C2)
R-(Q||R)-W
3. Elements
| Symbol | Meaning |
|---|---|
| R | Resistor |
| C | Capacitor |
| L | Inductor |
| Q | Constant Phase Element (CPE) |
| W | Warburg (diffusion) |
| G | Gerischer |
Notes
- Elements can be indexed: R0, C1, Q2, etc.
- Each element gets its own parameters automatically.
4. Parameters
After entering a circuit:
- all parameters appear in the Parameters panel
- you can edit their values manually
Important
Changes are applied when:
- you press Enter, or
- click Apply parameters
5. Presets
Use presets to explore typical cases:
- Two semicircles → two processes
- Depressed arc → distributed behavior
- Warburg tail → diffusion
- Capacitive limit → blocking electrode
- Inductive loop → inductive response
Preset → Load preset
6. Plots
Nyquist plot
- X-axis: real impedance Z′
- Y-axis: −Z″
- semicircles represent processes
- 45° line → diffusion
Bode magnitude
- |Z| vs frequency (log scale)
Bode phase
- shown as −Phase (deg)
- peaks point upward for capacitive behavior
7. Export
Export PNG
This saves:
- all plots
- circuit
- parameter values
8. Tips
- To separate two processes → use very different time constants
- To merge them → make parameters similar
- If the graph looks strange → check parameter values
- Extremely large or small values may produce unrealistic results
9. Limitations
Current version:
- Warburg is infinite (no finite-length diffusion)
- No graphical circuit builder (text only)
- Parameters must be entered manually
10. Typical mistakes
- missing parentheses
- wrong use of ||
- invalid element names
- forgetting to apply parameters