"Cross connect" integrators?

[Mark Todd]

I have a set of instructions for producing a device which includes the
following line:

"This low level signal (white noise) is fed through two
cross-connected integration stages (op-amp integrators) producing a
low frequency chaotic modulation signal."

Can anyone tell me how this "cross connection" is wired. My best guess
is to wire the output of each integrator to the input of the other
with their inverting inputs and outputs tied together.

It seems to be a strategy to derive second order modulation that does
not result in feedback. Why it produces a "low frequency" component
from white noise I do not understand.

I have never seen this done before, and the designer is no longer
contactable.

Any opinions on how and why this works would be most welcome.

Mark

 

[Tim Shoppa]

Can anyone tell me how this "cross connection" is wired.

Not from this distance. But a similar, easily mathematiically
described chaotic system (the Lorenz equation) is done with three
integrators at

http://frank.harvard.edu/~paulh/misc/lorenz.htm

In general to get chaoticity you need nonlinear terms.

Why it produces a "low frequency" component
from white noise I do not understand.

Integration generally smooths things out... in the most general case an
RC integrator is also a low-pass filter.

Your description has words that are related to reality but without a
schematic I don't think you'll get anything definite.

Tim.