User:Alexander T. J. Barron/Notebook/PHYC 307L Lab Notebook/Oscilloscope notes

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I lost all of my superior notes up to now, when my browser timed out. However here are my pictures, without text:

SJK 01:09, 17 September 2008 (EDT)
01:09, 17 September 2008 (EDT)
losing your notes was a real bummer! Also, it will make the "practice" nature of this lab a little difficult, because I don't know what was missing. One important thing that other people have been missing has been to record the model number and manufacturer of the oscilloscope and function generator, and also to describe how things were wired up. I don't know whether you had done this, but I do know that you took some pictures. The pictures could have been quite helpful (but not if you don't upload them!). So, make sure in your future labs to record the equipment used and how things were set up.

Also, it is difficult to judge how much was lost. I think your below notes are pretty good, except probably a little more description in certain areas of what you are doing. Also, a description of uncertainty when taking the measurements.

Now, the rest of the lab:

2) Triggering:

I started out with edge, rising trigger @ 0.00 V. This projected the typical sin wave, with slope 1 @ t = 0. When I switched to falling trigger, my sin graph changed phase by pi, with slope -1 @ t = 0. Video trigger gave me a slowly moving double-wave - none of the options cleaned it up. Pulse triggering yielded more gibberish until I set the "when" option to ≠ instead of =. The Pulse Width was set to 1.00 ms, so the ≠ makes sense.

3) AC Coupling

I set V amplitude to ~10 V. Switching to AC Coupling raises and advances in time the whole function a very little bit.

To measure fall time:

cursor: peak = 8.28 V, end square peak = 6.68 V. time to fall (8.28-6.68) V = 4.400 ms. (8.28-6.68)/8.28 = 19.3% total. For 90% fall time: 4.400 ms x 90/19.3 = 20.5 ms.


Now that I can see the more pronounced fall time:

Cursor: peak = 8.60 V, fallen side = 600 mV. 10% of 8.6 is .86, so moved the second cursor to 800 mV. fall time is 62.00 ms.

By the equation V = V0(e^-t/tau), tau = 62 ms.