LT-Spice Analysis 2

Electrical Circuits 1

ELECENG 301-602

By

Tyler Doro

3/24/15

Introduction

This report describes the use of the LT-Spice program, and some of its more advanced applications such as parametric analysis, DC sweep, and AC simulations.

Procedure

Open LT-Spice

Create a new schematic

Add circuit elements such that the circuit created resembles problem 2.110 from the text book (figure 1)

Change the 18k resistor value to {R}

Click Edit -> SPICE Directive

Type .STEP PARAM R 10 500 10 into the dialog box

Run simulation

Perform DC voltage sweep

Click Simulate ->Edit Simulation Cmd

Run DC sweep simulation

Run a AC simulation

Plot AC simulation

Acquire results

Figure 1

Results

Figure 2 (Parametric analysis and Vo graph above)

Figure 3 ( DC sweep and Vo graph above)

Figure 4 (AC simulation and graph above)

Questions

What should the new value of the 18K ohm resistor be in order for Vo to equal 2V?

From Figure 2 we can see that the value of the resistor should be changed to 72k.

What value should the input voltage be in order for Vo to equal 2V?

From Figure 3 we can see that the voltage required in order for Vo to be equal to 2V is 7V.

Plot the Vo signal of the AC Simulation

See Figure 4

Discussion and Conclusion

The results from this lab were very promising. At the end of this lab I had a greater understanding of how I can use the program LT-Spice for transient analysis, DC sweeps, and AC simulations. Using this program to manipulate circuit voltages could be very useful in an engineering application