User:David K. O'Hara/Notebook/physics 307 lab/Oscilloscope lab notes

Oscilloscope Lab

Purpose of this lab is to become familiar with oscilloscope operation and wiki editing. Safety:

Be cautious when moving energized electrical equipment. No open drinks or other unsafe behavior is acceptable while working with energized electrical equipment. To protect the equipment that will be used, do not exceed voltage or amperage ratings.

Equipment Used Tektronix tds1002 two channel oscilloscope BK Precision 10MHz sweep/function generator

Lab Procedure Becoming familiar with oscope controls. Triggering: allows a stable representation of the waveform to be displayed on the scope.

Effects of using different triggers: video - shows continuously moving waveform, difficult to read pulse - had no effect, display was similiar to video  edge - stable representation of waveform, generates a pulse when signal crosses a given threshold voltage

Measuring values off oscilloscope

using a 200hz sine wave signal from a function generator measure the peak-peak voltage (amplitude) and the period (giving frequency)

perform measurements using oscope display divisions, cursors, and finally measure function. measurement type        voltage          period               frequency display                   2.3  v           4.8   ms             205     hz cursor                     2.24 v           4.84  ms             206.4   hz measure                    2.24 v           4.840 ms             206.446 hz

compare AC coupling to DC coupling

AC coupling shows entire wave makeup, both AC and DC parts.

DC coupling shows waveform with only DC component. Filtered waveform.

measuring fall time.

set the function generator to output a square wave with 0 dc offset, and an amplitude of 8.6 volts @1.1hz measured the fall time from the peak of the signal to 10% of the signal to be 53.3 ms.

The time constant τ of the system is given by fall time = 2.197*τ

in this case τ is approximately .024.