PERIODICALLY FORCED PENDULUM: ILLUSTRATE PERIODIC, MULTIPLY PERIODIC AND CHAOTIC ORBITS.
The above sketch shows the hookup. The torque motor is driven by an audio oscillator attached to an audio amplifier (DC - so very low frequency of forcing is possible). Use the audio oscillator in the SINE WAVE MODE ONLY.
Clamp the pendulum firmly to a desk. Driver and amplifier look like:
The motor connects to the right rear output as shown below:
Adjust amplitude and frequency of forcing to get various states:
QT Movie of Periodic Orbits (Big Screen Version)
QT Movie of Chaotic Orbits (Big Screen Version)
©2000. John Hart, University of Colorado