* chua-circuit.i
* Chua's Circuit, Kimmo Silvonen 5.11.2012
* This file can be run (among others) with the APLAC version (7.80) used in the laboratory (saatavilla Kimmolta)

* Chua's Diode based on two parallel-connected piecewise linear negative resistances
* Details in Elektroniikka ja puolijohdekomponentit

* Chuan piirin netlist-tiedosto on muistirajoituksen takia kahdessa erikseen ajettavassa osassa. 
* Tiedostot voi ajaa esim. labran Aplac-versiolla 7.80 (Win/Linux), joka on saatavilla luennoitsijalta. 
* Osassa 2 u_1 ja u_2 on piirretty ajan funktiona: tuloksena on kaoottinen aaltomuoto.

opamp o1 1 2 3 0 $ nonideal opamp model used
opamp o2 1 4 5 0 $ nonideal opamp model needed
res r1 1 3 220
res r2 2 3 220
res r3 2 0 2.2k
res r4 1 5 22k
res r5 4 5 22k
res r6 4 0 3.3k

* Rest of the circuit
Res R  1 7 1.9k
Cap C1 1 0 22u U0=0.1
Cap C2 7 0 220u u0=0.0
Ind L  7 0 55

Sweep "uC2 as a function of uC1, R=1.9k, C1=22 uF, C2=220 uF, L=55 H" 
+ LOOP 8001 time LIN 0 120
+ GRID 
+ BIG_SCREEN
+ Y "uC2" "V" -2.4 2.4
+ X "uC1" "V" -10 10
* Minimal changes in component values cause radical changes in response, do have a try!
* OMG, this is chaotic behaviour!
* You might want to save the result
*+ EPS="chua.eps"

* Extra delay for drawing
For i 0 200
Print s "" lf
EndFor

* I'll change the pen after each 40 seconds of analysis
If t<40
Show XY vtran(1) vtran(7) width=2 color=Red
Endif
If (t>=40 and t<80)
Show XY vtran(1) vtran(7) width=2 color=Blue
Endif
If (t>=80)
Show XY vtran(1) vtran(7) width=1 color=Black
Endif

EndSweep