• Faculty may change the demo from its default setup (such as moving plugs and adding a capacitor on the circuit board to change damping and frequency of system). However, please do not change settings on the oscilloscope.

• However, if faculty run into any issues with the demonstration they may double check that the oscilloscope is set to a vertical scale of 500 mV / division and horizontal scale of 200 ms / division. Also ensure the voltage on the power supply is below 2.5 V.

• Adjust circuit board to the desired damped system setting.

• Briefly push down and release the red momentary button on the circuit board.

• To further show the difference between the critically damped system and over damped system, flip the switch on the board to increase the system's capacitance.

• Demonstration consists of a digital oscilloscope with a VGA output to the classroom A/V system, 10 Henry inductor, a choice of no resistance, 18000 ohm, and 24000 ohm resistors in the circuit (corresponding to under damped, critically damped, and over damped), a default 2.6 microfarad capacitor, which can be combined with a 4.5 microfarad capacitor.

• The amplitude of oscillation decays more rapidly as damping (resistance) increases, which has an affect on frequency.

• Ensure all wires are plugged in correctly as shown in the circuit board and power supply photos below.

• After transferring demo to the classroom, turn on the oscilloscope to adjust the settings for faculty.

• Ensure the oscilloscope is set to 500 mV / division for the vertical scale and 200 ms / division for the horizontal scale.

• Set the voltage on the power supply below 2.5 V.

Last Updated 2023 - University of Texas at Austin Physics Dept. - All Rights Reserved.