Visualization of the Diode-Inductance Circuit's Dynamics

    Normally to observe chaotic behavior in the system of a Diode-Inductance Circuit the applied voltage would be varied while the input frequency would be maintained close to that of the resonating frequency of the inductor and the reverse capacitance of the diode.  However, in our experiment we arbitrarily chose to demonstrate period doubling and chaotic behavior by varying the input frequency instead of the voltage.  In order to observe chaotic behavior in an oscillatory system one needs only to vary one parameter of the input or driving force, so while our methods are unconventional they still produce the desired results.

    The phase spaces from the data page and those below are useful in that they provide information about the dynamics of our system at specific values of the input frequency.  The Poincare Sections are a means of simplifying the phase space and demonstrate more clearly each stage of the transition from single periodicity to chaos in our system.  The Fourier Transformations illustrate the predominant frequencies that compose our output voltages.  Sometimes though it is helpful to get a more global view of the dynamics of a system by examining the entire range of a parameter at once, thereby allowing simultaneous comparison of periodic and chaotic behavior.  The bifurcation diagram is an excellent method of presenting this overview and provides a summary of the essential dynamics of our system.

Phase Spaces at Specific Frequencies

wpe16.jpg (7049 bytes)  wpe14.jpg (7197 bytes)  wpe13.jpg (8703 bytes) wpe12.jpg (7919 bytes)  wpe17.jpg (8518 bytes)  wpe18.jpg (9069 bytes) wpe19.jpg (8791 bytes)  wpe1A.jpg (8924 bytes)  wpe1C.jpg (8284 bytes)

Actual scope images:

The following are phase portraits as plotted on the oscilloscope:

Period doubling at 156.2 kHz        double.jpg (34524 bytes)

Period quadrupling at 128 kHz      quad.jpg (40929 bytes)

Chaos at 107.4 kHz                      chaotic.jpg (43605 bytes)

 

Poincare Sections

 

 

Fourier Transforms of the Output Voltages at Specific Frequencies

 

 

 

 

 

Bifurcation Diagram for our Range of Frequencies

Periodicity:       single        double      quadruple          octuple        chaos           octuple      quadruple      double        single

                      

Frequency:       16 kHz       32 kHz      57 kHz      61 kHz            111 kHz         124 kHz  130 kHz     149 kHz   177 kHz

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