User:David K. O'Hara/Notebook/physics 307 lab/Oscilloscope lab notes
Oscilloscope LabSJK 16:48, 15 September 2009 (EDT)
Purpose of this lab is to become familiar with oscilloscope operation and wiki editing.
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.
SJK 16:43, 15 September 2009 (EDT)
Tektronix tds1002 two channel oscilloscope
BK Precision 10MHz sweep/function generator
SJK 16:45, 15 September 2009 (EDT)
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.