The Rössler attractor challenge.

[GK]

My current digital camera refuses to capture acceptably focused video of my oscilloscope displays, although it focuses fine when taking single-shot photographs. So rather than video I've put together some pictorial illustrations of the computers manual/variable bifurcation control for a few systems instead.

System D:


System G:


System M:


System R:

 

[R_Gtx]

Could somebody explain what do exactly do this circuits do, and is there any propose for them?

Today, I posed myself the question "can Chuas' circuit be used as a RNG?", naturally, googling this question was first solution, and I found this interesting page.
(Sorry, if this has been posted before.)

[GK]

Could somebody explain what do exactly do this circuits do, and is there any propose for them?

Today, I posed myself the question "can Chuas' circuit be used as a RNG?", naturally, googling this question was first solution, and I found this interesting page.
(Sorry, if this has been posted before.)

That is an interesting page. Statistical analysis somewhat along those lines is something that I'd like to get around to eventually, just for my own experimentation and edification.

[EEVblog]

Every time I see this thread pop-up I'm reminded how I lost the circuit I was going to build for this 

[richmit]

[Note to mods:  I didn't know if it was better to respond to the old thread or start a new one.  Please feel free to move this post if I made an error in etiquette.]

I'm a little late to the game, but here is mine!

I posted a few movies on my web page -- including a few failed attempts:

      https://www.mitchr.me/SS/Rossler/index.html

[Gyro]

Now that's why you want to keep an old analogue scope around! 


P.S. I think you did the right thing, good threads need to be resurrected and refreshed, it's bad threads that should be left to rot.

[RoGeorge]

https://www.mitchr.me/SS/Rossler/index.html

Very nice website!   
(though the Rössler attractor project is not linked in your home page)

Since you already have a webplace to store images, you can make animated gifs instead of movies.  The advantage would be that a gif can be embedded between 'img' tags, while a movie can not be played here.

[richmit]

https://www.mitchr.me/SS/Rossler/index.html

Very nice website!   
(though the Rössler attractor project is not linked in your home page)

Since you already have a webplace to store images, you can make animated gifs instead of movies.  The advantage would be that a gif can be embedded between 'img' tags, while a movie can not be played here.

Thank you RoGeorge.  I didn't realize I could inline GIFs in a post!

Here is the movie I mentioned in my original post:



And here is one my more interesting failures:

[iMo]

Try this one:

More on www.chaotic-circuits.com

[richmit]

I built this (or tried to), and got a sinusoid.  I built it again on my lunch break today. Got another beautiful sinusoid!  At least my simulations show the right thing...

I'm sure I'm doing something silly, so I'm going to set the breadboard aside for a bit and finish up my Lorenz board.  When I look at it again, I'll no doubt slap myself when I realize whatever I've done wrong.

[richmit]

One more.  The Lorenz Attractor.  The details are here:

     https://www.mitchr.me/SS/lorenz/index.html#sim-vis-analog

This first image is a long exposure with the scope intensity set very low:



And here is a movie:

[iMo]

Or this simple one:

More on www.chaotic-circuits.com

[iMo]

I built this (or tried to), and got a sinusoid.  I built it again on my lunch break today. Got another beautiful sinusoid!  At least my simulations show the right thing...

I'm sure I'm doing something silly, so I'm going to set the breadboard aside for a bit and finish up my Lorenz board.  When I look at it again, I'll no doubt slap myself when I realize whatever I've done wrong.

There is an IEEE paper on that circuit you may study:

http://www.chaotic-circuits.com/wp-content/uploads/2016/06/Simple-Two-Transistor-Single-Supply-RC-Chaotic-Oscillator.pdf

[richmit]

I built this (or tried to), and got a sinusoid.  I built it again on my lunch break today. Got another beautiful sinusoid!  At least my simulations show the right thing...

I'm sure I'm doing something silly, so I'm going to set the breadboard aside for a bit and finish up my Lorenz board.  When I look at it again, I'll no doubt slap myself when I realize whatever I've done wrong.

There is an IEEE paper on that circuit you may study:

http://www.chaotic-circuits.com/wp-content/uploads/2016/06/Simple-Two-Transistor-Single-Supply-RC-Chaotic-Oscillator.pdf

Third time was the charm.  What was I doing wrong?  I didn't have a BC547C on hand, so I dug around in my parts bin and found a bag of vintage Motorola 2N2222.  Now I haven't used a BJT in a can for a long time, and I poked the thing into the bread board the wrong way around!  Doh!



Anyhow... This circuit is super sensitive!  Tiny changes in the value of R4 deliver completely different results.  Even things like temperature cause changes.  For the following movie I cooled down Q1 and captured the output as the transistor warmed up.



Obligatory breadboard shot:

[richmit]

Or this simple one:

More on www.chaotic-circuits.com

I finally got around to this one!  It's pretty cool.





The GIF above is just a 5 second preview of the 30 second movie.  The full movie as well as one captured with my Siglent SDS2354X Plus can be found at the link:

               https://www.mitchr.me/SS/eeChua/index.html

[RoGeorge]

Nice one, congrats! 

For the curious, the I-V characteristic of those non-linear resistors (and more) is shown in these PDFs linked here:
https://www.eevblog.com/forum/beginners/tek-475a-vs-tek-2445/msg4401871/#msg4401871

[iMo]

What if the 2 transistor circuit would modulate the Chua circuit (or vice versa)..

[Smokey]

Well, I think I have got it down to four op-amps and a multiplier now (after getting some inspiration from the circuit I mentioned previously). Subjectively, it does not seem quite as chaotic as the old circuit, but it still gives quite a good display on the CRO. The clipping is gone too.

OK, good work!

In case anyone out there has an inclination to experiment with 3-D projections, all the information required to get started is here:

What book is this?  Google doesn't seem to know, which is unexpected.

[richmit]

What if the 2 transistor circuit would modulate the Chua circuit (or vice versa)..

All sorts of interesting things happen when you couple a couple of these circuits together.  Even something supper simple like a free running pair of RC oscillators.  For example, in the schematic below we have a 555 delivering a 0.7V squarewave to a couple of RC oscillators:



The result is pretty cool:

.

That gif is a 5 second sample.  The full movie and a bunch of other stuff is at the link:

   https://www.mitchr.me/SS/eeCoupledRC/index.html