[sdiy] Logistic Equation chaos engine?

[Tim Stinchcombe]

> Hi ..still on the topic of Lorenz attarctors and chaos..it 
> might be fun to see if one could  design an anlogue circuit 
> that solves the so called' logistic equation' (for those who 
> like maths see 
> http://mathworld.wolfram.com/LogisticEquation.html for a nice 
> review and pretty pictures) . The solutions to this equation 
> (or at least the recurrence relation thats based on this 
> equation) can approach chaos ..and show period doubling and 
> bifurcation etc. I would guess  it must be possible to solve 
> simple recurrence relations using analogue computer type circuits?

Yes indeed. Dan Slater did an article in the Computer Music Journal in 1998
entitled 'Chaotic Sound Synthesis' in which he gives a patch for the
logistics equation using 3 Moog 902 VCAs and a 928 sample & hold. It used to
be up on the web, but I haven't been able to find it at all recently (just
some references to it). It looks like Dan Slater has completely removed it
from his website. I'd be surprised if searching in Google didn't reveal a
few circuits.

Tim

__________________________________________________________
Tim Stinchcombe 

Cheltenham, Glos, UK
email: tim102 at tstinchcombe.freeserve.co.uk