Friday, February 10, 2017

Blog 5 group 1

1. Functional check: Oscilloscope manual page 5. Perform the functional check (photo).
Figure 1: Shows the functional check

2. Perform manual probe compensation (Oscilloscope manual page 8) (Photo of overcompensation and proper compensation).
 Figure 2: shows overcompensation on the signal.
Figure 3: Shows proper compensation on the signal.

3. What does probe attenuation (1x vs 10x) do (Oscilloscope manual page 9)?
When you have the attenuation set at 1x then you have a max bandwidth of 7 MHz.  To utilize the full bandwidth that the oscilloscope can use, you must have it set on 10x attenuation. 

4. How do vertical and horizontal controls work? Why would you need it (Oscilloscope manual pages 34-35)?
The horizontal and vertical controls adjust the viewing area of the sinusoidal wave. The vertical will adjust it up and down, and horizontal will adjust left and right.  If the wave is too large, and you wish to see a certain section of it, then you can adjust the vertical and horizontal controls to see it.  You can use the auto range which adjusts the viewing window for you so you don't normally have to use those two knobs. 

5. Generate a 1 kHz, 0.5 Vpp around a DC 1 V from the function generator (use the output connector). DO NOT USE oscilloscope probes for the function generator. There is a separate BNC cable for the function generator.
a. Connect this to the oscilloscope and verify the input signal using the horizontal and vertical readings (photo).
Figure 4: Verifies the signal sent from the function generator
b. Figure out how to measure the signal properties using menu buttons on the scope.
If you hit measure then whatever channel you are using you can find out the scale and measurements

6. Connect function generator and oscilloscope probes switched (red to black, black to red). What happens? Why?
When you swap the leads on the probe, you don't get any connection on the oscilloscope.  The black must be the ground and must only allow current to flow one direction.

7. After calibrating the second probe, implement the voltage divider circuit below (UPDATE! V2 should be 0.5Vac and 2Vdc). Measure the following voltages using the Oscilloscope and comment on your results:
Figure 5:  Va= 2.00V and Vb=1.00V after measuring from the oscilloscope. 

Channel 1 read 1.00 V and then Channel 1 peak to peak was 2.02V for the voltage across R4.
(comment on results)
8. For the same circuit above, measure Va and Vb using the handheld DMM both in AC and DC mode. What are your findings? Explain.
DC voltages: 
Vb= 2.69 Volts
Va= 1.34 Volts
AC voltages:
Vb= .238 Volts
Va= .0118 Volts
Our data appeared unintuitive to us because we would have assumed our AC voltage readings would be higher than our DC voltage readings. Looking back on our procedure we used our handheld multimeter as opposed to our more versatile and accurate DMM. However, we believe that the AC readings must be a peak reading as opposed to a peak to peak reading.

9. For the circuit below
a. Calculate R so given voltage values are satisfied. Explain your work (video)
Video 1: Shows how to calculate R, which we discovered to be 5.767 k ohms
When using the calculator to solve the final equation, we discovered our value to be 5.767 kOhms instead of 6.072 kOhms like it shows in the video.

b. Construct the circuit and measure the values with the DMM and oscilloscope (video). Hint: 1kΩ cannot be probed directly by the scope. But R6 and R7 are in series and it does not matter which one is connected to the function generator.
Video 2: Shows how we obtained our readings from using the oscilloscope.
When constructing our circuit, we could not locate the exact resistor value that we calculated at R7. We ended up using a resistor that was 5.58 kOhms.  We got a peak to peak value of 12.3 Volts across R7, and we received a peak to peak value of 2.20 Volts for R6.

10. Operational amplifier basics: Construct the following circuits using the pin diagram of the opamp. The half circle on top of the pin diagram corresponds to the notch on the integrated circuit (IC). Explanations of the pin numbers are below:
a. Inverting amplifier: Rin = 1kΩ, Rf = 5kΩ (do not forget -10 V and +10 V). Apply 1 Vpp @ 1kHz. Observe input and output at the same time. What happens if you slowly increase the input voltage up to 5 V? Explain your findings. (Video)
Video 3: Shows and explains our findings when you slowly increase the voltage.

b. Non-inverting amplifier: R1 = 1kΩ, R2 = 5kΩ (do not forget -10 V and +10 V). Apply 1 Vpp @ 1kHz. Observe input and output at the same time. What happens if you slowly increase the input voltage up to 5 V? Explain your findings. (Video)
Video 4: This video shows the difference between the non-inverting and inverting amplifier.


  1. The blog looks great. I couldn't find any errors. Keep up the good work. I do have a very small complaint though. You probably should have re scaled the oscilloscope for the pictures. Just so people can see the differences between the two waves. However, that issue is completely arbitrary, keep up the good work.

    1. Thanks Alec! Yeah we are still getting comfortable scaling and measuring on our oscilloscope.

  2. Our oscilloscope pictures are very similar except for #7. Was your zoom window farther out or what? Our two readings were evenly spaced apart and the amplitude was much larger with a larger frequency. On #8 our voltages were similar. Good job on the blog though everything looks good!

    1. We used our autofocus button but its important to note that your oscilloscope was displaying the pk-pk value also which would explain the difference of amplitude.

  3. You guys have the necessary info for question 3, but could elaborate more on what probe attenuation does. From what I understand, probe attenuation adjusts the voltage of the incoming signal by increasing impedance. This is done so that more accurate measurements can be taken.