🚀 go-pugleaf

In article <1992Oct05.234429.10063@bnr.ca> kelvinp@crchh447.bnr.ca (Kelvin Porter) writes:
>I remember, way back in the early days of 'Strange Attractors', seeing an article
>(written I believe by University of Texas Non-Linear Dynamics Professors)
>which mentioned capacitors that exhibited chaotic characteristics...
>It may have been in the Springer-Verlag "Intelligeneer"?????
>
>My question is can direct me to reference(s) regarding chaotic circuitry or better
>yet post ASCII schematics?
>

There are a mere 5 pages on 'electronic chaos' near the end of *Chaos
Cookbook* (Joe Pritchard, Butterworth/Heinemann, 1992) p. 342-346.
His only ref. is a paper by Testa, Perez & Jeffries published in
*Physical Review Letters* (1982) p. 714-717 (no title). The circuit
he uses replaces a capacitor in an LCR (inductor-capacitor-resistor)
oscillator with a varactor, a variable capacitor whose capacitance varies
with applied voltage, introducing non-linear feedback into the circuit.
The project is geared toward observing phase portraits with an oscilloscope.
He does state, "Although I've not done this, I feel that it should be
possible to run this circuit at audio frequencies & monitor the output
on a loudspeaker; this could interesting to see what the different states
of the system sound like as well as what they look like."

I also recall J. Gleick, _Chaos: Making a New Science_, Penguin, New York, 1987
discussing some analog computing work done at Santa Cruz, but of course he
doesn't discuss any circuits.

The Pritchcard stuff is a start if you know electronics, you'd have
to learn at least some oscillator stuff if not. A less messy approach
would be to simulate the circuit on a computer & send the simulation
results to an audio frequency generator, but you'd have to know the
math & device data for modeling the devices. Have fun.

Dale Parson