Oscillations and Waves > Oscillations > Nonlinear Systems
 DCS# 3A95.50
NONLINEAR OSCILLATOR
nonlinear oscillator
APPARATUS
rotary motion sensor 202-13-E2
disk with offset rod 202-13-E2
two springs 202-13-E2
string 202-13-E2
mounting bracket 202-13-E2
mechanical driver 202-13-E2
ringstand 202-13-F
DC power supply 202-08-D
pc running LoggerPro 206

DESCRIPTION
Adjust the driver frequency and amplitude for chaotic motion.  Use the rotary motion sensor to make a phase plot.

NOTES
 
Edge mass should be at the top of the disk when springs are stretched equally.  Wrap string around large diameter pulley one and a half turns.

The followings settings work:
driver amplitude of 4.5 cm (as marked on frame)
power supply voltage (which determines driver frequency) = 4.82 V
maximum stretched length of spring ~40 cm
3 mm magnet gap

Use LoggerPro experiment file "nonlinear oscillator demo" or, if things go wrong, "nonlinear oscillator data".
Settings are:
Pasco rotary motion sensor, rotary high
experiment length = 300 sec
sample rate = 50 pts/s
plot position vs. time or angular speed vs. time
angular variables have no particular units

other data from Pasco:
1440 points/rev
1 pt = 0.25 degrees
disk diameter = 5 cm
edge mass = 10 g
Vdrive = 4V gives f = 0.71 Hz
ksp = 0.45N/m