User:Randy Jay Lafler/Notebook/Physics 307L/2010/08/30

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Oscilloscope Lab

SJK 15:17, 24 September 2010 (EDT)
15:17, 24 September 2010 (EDT)
This is a pretty good primary notebook. It's a little sparse on information sometimes...however, I peeked at your e/m notebook and can see that you're including more information in that one, which is great.
Oscilloscope
• In this lab we used a signal generator to produce a signal, and analized the signal with an oscilloscope. Our goal was to learn how the oscilloscope functions.

Procedure

SJK 15:14, 24 September 2010 (EDT)
15:14, 24 September 2010 (EDT)
The pictures of setup are good. Important, too, to record the make and model numbers of the equipment here in your primary notebook.
• We connected the signal generator to the oscilloscope with a BNC cable.
• Set the signal generator to 200Hz. Measure the voltage and frequency of the signal using the grid, the cursor, and the measure function at high, medium, and low output.

Measurements

1) Measurments for medium output

```Using oscilloscope grid
Amplitude = 6V
Frequency = 200Hz
Using the cursor
Amplitude = 6.12V
Frequency = 200Hz
```
Using Measure Function
```Using measure function on oscilloscope
Amplitude = 6.20V
Frequency = 200.8Hz
```

2) Measurements for high output

```Using the cursor
Amplitude = 22.2V
Frequency = 200.0Hz
Using measure function on oscilloscope
Amplitude = 22.4V
Frequency = 200.4Hz
```

3) Measurements for low output

```Using the cursor
Amplitude = 2.10V
Frequency = 196.1Hz
Using measure function on oscilloscope
Amplitude = 2.08V
Frequency = 200.4Hz
```

4) Measurements with the DC offset on full and with the same low output

```Using cursor
Amplitude = 2.00v
Frequency = 192.3Hz
Using measure function on oscilloscope
Amplitude = 2.20v
Frequency = 200Hz
```
• But the frequency is fluctuating between about 150-300Hz.

Triggering

• Edge triggering shows the wave as an image on the display by assigning a point on the wave to t=0 with the trigger arrow.
• Rising edge triggering catches the wave at a point where the slope of the wave is positive, and Falling edge triggering catches the wave at a point where the slope is negative and falling.

Fall time

Square Wave Fall Time
SJK 15:16, 24 September 2010 (EDT)
15:16, 24 September 2010 (EDT)
Here it's a little unclear how you're measuring fall time, 100% to 10% or other method?
• We created a square wave at 10Hz and 7V and using AC coupling.
• We measured the fall time as the time change during the dip in the wave.
• Using the cursor we found a fall time of 45.20ms.
• Using the measure function we got a fall time of 39.99ms.
• The RC constant is the fall time divided by 2.197.
• RC=18.20ms