Monday, February 6, 2017

Week Five

Week Five

Not Shocking People

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


Figure 1&2: Images of out functionality test

2. Perform manual probe compensation (Oscilloscope manual page 8) (Photo of overcompensation and proper compensation).

Figures 3 & 4: Image on the right of slight over compensation, image on the left of proper compensation.

3. What does probe attenuation (1x vs 10x) do (Oscilloscope manual page 9)?

1 X: Whatever your probe is reading, that is what the measurement truly is. 
10 X: Whatever your probe is reading, your probe will multiply the display times 10.

4. How do vertical and horizontal controls work? Why would you need it (Oscilloscope manual pages 34-35)?

There are two knobs allowing you to change the horizontal and vertical position of the wave function. The horizontal position control allows you to establish the time between the screen center and the trigger, and can help you establish the period of the wave function. The vertical controls can allow you to establish the peak and peak to peak voltage of the voltage. 

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 5: Image of our function as specified in the question

b. Figure out how to measure the signal properties using menu buttons on the scope.

Select the measure button. From there you can select the different forms of measurement that automatically read the data from the wave function.

6. Connect function generator and oscilloscope probes switched (red to black, black to red). What happens? Why?

The signal held static. The warning saying "Unknown signal" appeared. It was not able to be read. This is because the common ground of the oscilloscope is applying zero volts to the function generator, making it short. 

7. After calibrating the second probe, implement the voltage divider circuit below (UPDATE! V2 should be 1.0Vac and 2Vdc). Measure the following voltages using the Oscilloscope and comment on your results:

*Changed to be able to match function generators limitations
a. Va and Vb at the same time (Photo)

Figure 6 & 7: Photo on the left is of  the measurements placed side by side. The second channel measured a small indeterminate value whilst the first channel measured 750 mV(pp)

b. The voltage across R4.

DMM Measurement: DC=1.34 V    AC = 0.354 V

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.

Va: DC=1.348V   AC=0.353V

Vb: DC=2.698V   AC=0.710V

9. For the circuit below
a. Calculate R so given voltage values are satisfied. Explain your work (video)

Figure 8: Video showing how R value is found.

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.

Figure 9 & 10: Videos, measuring resistance

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:
2: Negative input 7: +10V
3: Positive input 6: output
4: -10 V 5: DO NOT USE
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)

Figure 11: Inverted Amplifier

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)

Figure 12: Non-inverted amplifier


  1. For #8 we got different values and i think you missed the explanation for this question I think you should find the voltage across R4 .

    1. Voltage Accross R4 is part of question 7. Thank you though.

  2. For numbers 7, 9 and 10 they could use some text to go along with the videos just for some extra clarity. For 9 part A, my group got the same value but we did it a different way just using the voltage divider equation.

  3. We found something different for Q3, but the rest our values are pretty close. you may want to explain the videos a little more clearly.

    1. We will check our work and explain better, thank you.

  4. The blog is organized and the questions are well-explained. But I think question 5a needs some explanation for clarity. Question 8 result is the same as our result for the DC and AC part. Also, for Question 9a, we got the same value but we use KVL and ohm's Law to find the resistance.

    1. We will add some explanation on problem 5a. Thank you.

  5. On your question 5a, we encountered something similar with the "blurring" of the wave on the Oscilloscope. Nicely done pcitures!