ECE 240 – Electrical Engineering Fundamentals
PSPICE Tutorial #9
Using Sinusoidal Inputs in PSPICE
In this tutorial, we will review the use of PSPICE to simulate a circuit with a sinusoidal input.
Figure 1 shows the PSPICE schematic for a circuit that was analyzed in class. The original
circuit had a sinusoidal input 9 cos 2t. Note the use of the VSIN source for this input. The
VOFF is set to zero. The VAMPL is set to 9. The FREQ is set to the frequency in Hz. For this
source the frequency in Hz is 2/(2π) = 1/π = 0.3183.
R1
3
VOFF = 0
VAMPL = 9
FREQ = .3183
1
L1
R3
2
2
1
V
V1
1
R2
1
L2
.5
1
C1
I
.25
0
Figure 1. PSPICE Schematic
Probes are placed in the circuit to measure the voltage across the resistor and the current through
the inductor. Since we want to plot the voltage and current versus time, the Transient analysis is
used. The Simulation Settings are shown in Figure 2. Note that the period of the input
waveform is approximately 3 seconds. Thus, TSTOP was set to 9 seconds to provide a display
of approximately 3 cycles. Another important difference is that the SKIPBP box was NOT
selected. In this case PSPICE will let the circuit run to steady state BEFORE producing the plot.
Thus, the solution will correspond to the steady state solution that we found in class. The
method of phasors only produces the steady state solution. The transient part of the solution
(homogeneous solution) will not appear.
Figure 2. Simulation Settings for Steady State Analysis
The results of the simulation are shown in figure 3. As expected, the voltage and current
produced have the same frequency as the input. They only vary in amplitude and phase.
Compare these results to the ones obtained in class.
2.0
0
-2.0
0s
V(R3:2)
I(L2)
2s
4s
6s
Time
Figure 3. Voltage and Current Waveforms
8s
10s