Physics307L F08:People/Gooden/Notebook/070827

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see comment
Steven J. Koch 00:52, 29 August 2007 (EDT):Overall, excellent lab notebook!

set up

I set up the oscilloscope with a BNC cable to ch1 connecting to the low output of the generator. Generator producing sine waves at ~50 Hz. Set on DC coupling.

ch1 positioned at v=0. Trigger set at v=0, slope-rising.


Measurement- Voltage with original wave

    1. using the grid to measure amplitude  
       of the wave I get ~4.4 volts.
    2. using the cursor mode I find an      
       amplitude of ~4.64 volts.
    3. Using the measure control I again   
       find an amplitude of ~4.64 volts. 
    REPEATS:making voltage measurements using the measure 
    and cursor controls for waves of different 
    applitudes and 20 and 30 hz.
    1. 20hz wave, I find 2.72 volts after   
       adjusting the amplitude.
    2. 30 hz with another adjusted amplitude I find
       1.36 volts as the amplitude.

Measurements- frequency - original wave (f=1/T)

    1. Grid- I find period of ~20ms and so for frequency I find ~50hz
    2. Cursor- I find a frequency of ~50Hz
    3. Measure control- I find a frequency of ~49.50 Hz
    REPEATS:making frequency measurements using the measure 
    and cursor controls for waves of 2.4v 
    applitudes and 30 hz.
    1. Cursor- 30.6 Hz
    2. Measure control- I find 30.6 Hz
       * Trying these functions for different types of waveforms
        (square wave, etc) to measure frequency and amplitude
        the oscilloscope seems to do so properly.*
      **Dr. Koch helped to explain calculate frequency from period and to use the
        functions on the oscilloscope**


see comment
Steven J. Koch 00:44, 29 August 2007 (EDT):Great description!
   A) What does triggering on the rising edge mean?
       - this means that the trigger is set at a specified voltage on the 
         oscilloscope,and when the waveform reaches that value and is increasing, 
         event is registered.

AC Coupling

see comment
Steven J. Koch 00:51, 29 August 2007 (EDT):Excellent work on the AC coupling and in particular the calculation of the RC constant. I couldn't find anything when I tried either, but Antonio did find an article that looked promising.
    A)Read the ac coupling article
    B)Getting a voltage of about 12V, and then looking at the AC coupling to shift the signal
      back to zero voltage, and then decreasing the sec/div and volts/div a distinct 
      but 'noisy' sine component appears. The amplitude of the wave is ~10mV and a frequency
      of ~50kHz.
    C)Measuring Fall time - cursor function
        1. Using 1.12 volt square wave, and measuring with the cursor command I find a 
           fall time of ~52ms
        2. 880mV square wave, I find ~52ms
    C) Measuring Fall time - Measure function
        1. 880mV square wave, I find ~50ms
        2. 1.12 V square wave, I find ~50ms
    D)To find the RC constant we can use the equations given to us in the wikipedia article
      on the lab outline. The equation gives us Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "":): {\displaystyle .1=(exp(-t/s))}
 where t is the
      fall off time calculated previously and s is the RC constant. Solving this equation I   
      find s=22.5 milli sec.
    E)I was unable to find any information on the RC constant that I should expect on 
      the internet.

    ** Had help from TA in calculating the RC constant, and from Dr. Koch in using the 
       correct equation to do so.**
see comment
Steven J. Koch 00:51, 29 August 2007 (EDT):Great work giving credit!


    1)Using the FFT math function to find the frequency of a sine wave and with help from Zane
      Gibson, I find the frequency is 80Hz. Which matches up with what the wave generator is