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Run PSpice key. The result will be a blank screen with an x-axis
extending from 0 s to 5 ms.
The first quantity of interest is the current through the circuit, so
Trace-Add-Trace is selected followed by I(R) and OK. The resulting
plot of Fig. 15.110 clearly shows that there is a period of storing and
discharging of the reactive elements before a steady-state level is established.
It would appear that after 3 ms, steady-state conditions have
been essentially established. Select the Toggle cursor key, and leftclick
the mouse; a cursor will result that can be moved along the axis
near the maximum value around 1.4 ms. In fact, the cursor reveals a
maximum value of 16.4 A which exceeds the steady-state solution by
over 2 A. A right click of the mouse will establish a second cursor on
the screen that can be placed near the steady-state peak around 4.4 ms.
The resulting peak value is about 14.15 A which is a match with the
longhand solution for Fig. 15.35. We will therefore assume that steadystate
conditions have been established for the circuit after 4 ms.
COMPUTER ANALYSIS ⏐⏐⏐ 691
FIG. 15.110
A plot of the current for the circuit of Fig. 15.109 showing the transition from the transient state to
the steady-state response.
Let us now add the source voltage through Trace-Add Trace-
V(Vs:+)-OK to obtain the multiple plot at the bottom of Fig. 15.111.
Forthe voltage across the coil, the sequence Plot-Add Plot to Window-
Trace-Add Trace-V(L:1)-V(L:2) will result in the plot appearing at
the top of Fig. 15.111. Take special note of the fact that the Trace
Expression is V(L:1)�V(L:2) rather than just V(L:1) because V(L:1)
would be the voltage from that point to ground which would include the
voltage across the capacitor. In addition, the � sign between the two
comes from the Functions or Macros list at right of the Add Traces