Monday, February 6, 2017

Week 5

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

Above is the Oscilloscope from page 5.  

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

Above is the same picture used in question #1! 

Above is the overcompensated oscilloscope. 

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

Basically, when attenuation is set to 1x the max bandwidth is 7 MHz.  For full usage of the bandwidth it must be at 10x.  The default setting is 10x, so the smaller it is the more accurate it will be.  

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

Changes the display of the waveform to on and off, selects scale factors, and displays waveform math operations.  

Adjusts math waveforms and the horizontal position of a channel.   

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).

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

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

The black wire in the scope has a very hard ground so anything connecting to it is going to be ground. and the small wire in the function generator is going to short the generator.  There is no current going through the circuit because it is shorted.  

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:

a. Va and Vb at the same time (Photo)

b. Voltage across R4.

1 V.  R4 + R5 = 2 V, R5 = 1 V, so R4 = 1 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.


The voltage across each resistor is 1.67DC V. we get 1.75 V across R5 (Va), and get 3.42V across R5 and R4 combined. 3.42-1.75=1.67V so that will be the voltage across R4 which is near to our calculated value for AC.

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

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)

As we increase the voltage, the amplitude on the input and the output gets larger.  This makes sense because on the graph the larger the voltage the larger the amplitude will be.  The amplitudes will eventually cross into each other but that is no problem.  The input and the output are opposites of each other, which again makes sense because -1V and +1V cancel to make zero, as well as -5 V and +5 V.  

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)

The non-inverting amplifier measures the same as the inverting amplifier.  This makes sense to me because all we were changing is the circuit set up, we aren't changing any voltage inputs or outputs.  Also as we increase our voltage up to 5 volts the amplitude again gets larger, which makes sense because the amplitude is the voltage measurement.  In channel 2 the peak is 6 volts. As we increase to 5 volts channel 2 (output) levels off at 6 volts while the input voltage keeps increasing.  


  1. Good job guys. I would do some adjusting with your text font and size, there were some points in your blog it was hard to tell which was the questions and the answer. For the last question, we received different values for our non-inverting vs inverting amplifiers. We had a lot higher peak to peak values for our non-inverting amplifier. Which makes sense because we are calculating different gain values which will change the outputs.

    1. About the font i am going to be more aware about that so next time i am going to make it clear
      For the last question i think most of the groups had problem with it and we have a really confusing with the function generator.

  2. I noticed something in number 6. If you connect wires to the opposite connectors you get an error in the oscilloscope. The wave is very noisy.

    1. Yes you are write first we thought that the problem is because the negative and positive than we realize that and correct the answer

  3. Similar to Austin and Scout's group, I believe you could touch on probe attenuation a bit more. The way I understand it, the higher the attenuation (#x) the more impedance there is, which lowers the incoming voltage so that more accurate measurements can be taken. Also it is likely beyond what we are doing in our class, but there are even higher attenuations such as 100x for even higher voltages.

    1. Yes you are right but in this question we had a problem with it so we let dr kaya to help us with it