.ChaoticCircuits.ColpittsCircuit

Information

Colpitts' circuit is a simple nonlinear circuit which shows chaotic behaviour, based on a transistor.
Note: There are different variants of the Colpitt's oscillator. The one used in this example is based on:

• [Buscarino2014]
• [Kennedy1994]

Plot v1 vs. v2.
Default parameter RE = 5000 Ω (AnalyticEquations and IdealCircuit) resp. RE = 2000 Ω (Improved Circuit) shows nearly periodic results, i.e. the result varies within a narrow band. It seems that this circuit is extremely sensible.
Change parameter RE = 500 Ω to obtain chaotic results.

Note that initial condition = 0 is sufficient!

Note: The AnalyticEquation and the IdealCircuit use a simple transistor model according to the following equations:
iC = β*iB
Ron*iB = if vBE≤Vth then 0 else (vBE - Vth)

Contents

Name	Description
AnalyticEquations	Colpitts chaotic Circuit
IdealCircuit	Colpitts chaotic Circuit
ImprovedCircuit	Colpitts chaotic Circuit