paraphrase
alq8
report_4_ece240l.docx
Introduction
In this experiment we made preliminary calculations of two circuits and then designed them with PSPICE. After analyzing our circuits, we programmed PSPICE to plot specified voltage cycles. PSPICE is an effective tool for simulating circuits, but it does have limitations. We learned how computer generated models can give data that is different than what is expected.
Step 1: First, analyzed the circuit shown in Figure 4.1 and made preliminary calculations to find I1 and I2.
Figure 4.1:
We then designed and analyzed the circuit in PSICE.
As we compared our calculated values with the PSICE results, we observed that PSPICE was showing 8.000pA instead of the calculated value of zero.
Step 2: Next, we made preliminary calculations of Figure 4.2 and designed in PSPICE.
Figure 4.2:
Assuming vi(t) was a 1kHz square wave with a 15 volt peak, we programmed PSPICE to plot the first two cycles of Vo(t). To plot these first two cycles, the x-axis needed to start at 0 ms and stop at 2ms.
We then repeated this step for the 10th and 11th cycles of Vo(t) by programming PSICE to plot from 9 ms to 11 ms.
Step 3: We then replaced the circuit with vi(t) as a sine wave with peak voltage of 15 volts and a frequency of 1kHz.
Next, we plotted voltage versus time for the first two cycles by programming PSPICE to plot from 0 ms to 2 ms.
Lastly, we plotted cycles 9 through 10 by programming the plot to be from 9 ms to 11 ms.
Discussion
As is mentioned in step 1, we observed that PSPICE measured 8.000pA instead of the calculated value of zero. We concluded that this is because PSPICE makes imperfect measurements and such differences between the expected values should be expected. Because 8.000pA is so minute, it can be considered as 0A.
Also, during step 3 we observed that our sine wave initially was square-like, instead of smoothly curved. In order to produce a more rounded curve, we had to change the increment to 100 ns. The negative result of this was that PSPICE took more than one minute to do the calculations required to produce the plot. Even though this demonstrated that improving our simulation can cost more time, PSPICE is still an invaluable tool for simulating circuits. PSPICE has so many functions that an enormous amount of time needs to be spent learning about this useful tool.
Conclusion
This experiment allowed us to explore the basic mechanics of PSPICE. We were not only able to learn about how to graph the output voltage over time, but we also learned how to manipulate the graphical display to be viewed easier. Even though the graph may not be perfectly smooth, we can fix this by decreasing the step size that the program uses to calculate the values for the graph.
