In our previous post “Impedance Spectroscopy 101”, we focused on the fundamentals of impedance spectroscopy and derived both Bode and Nyquist representations of impedance, along with the mathematical relations linking impedance and frequency for several basic AC circuits.
In this follow-up post, you'll find a simple interactive simulator that allows you to experiment with these common equivalent circuits and observe the immediate changes in the resulting impedance spectra.
IS Simulator
In the dropdown menu below, you can select the AC circuit you'd like to simulate. Use the sliders to define the values of the resistor \(R\), inductor \(L\), and capacitor \(C\). The corresponding impedance spectra are displayed in the figures below.
When simulating the parallel RC circuit, we suggest to start with the following parameters for meaningful results: \(R = 100 \; \Omega\) and \(C = 1 \; \mathrm{\mu F}\).
On the other hand when simulating the series RL circuit, we suggest to start with the following parameters for meaningful results: \(R = 0.01 \; \Omega\) and \(L = 1 \; \mathrm{mH}\).
When simulating RLC circuits, we recommend starting with the following parameters for meaningful results: \(R = 10 \; \Omega\), \(L = 10 \; \mathrm{mH}\) and \(C = 100 \; \mathrm{\mu F}\).
Bode plot of impedance magnitude: \(|Z|\) as a function of frequency \(|Z(f)|\).
Nyquist representation of impedance: Resistance (\(R\)) vs. Reactance (\(X\)) or Real part (\(Z'\)) vs. Imaginary part (\(Z''\)).
Nyquist representation of admittance: Conductance (\(G\)) vs. Susceptance (\(B\)) or Real part (\(Y'\)) vs. Imaginary part (\(Y''\)).
