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126 2. Tutorial
In[30]:= oscillatorMNA2 = CircuitEquations[oscillator,
AnalysisMode −> Transient, ElementValues −> Symbolic,
InitialConditions −> All];
DisplayForm[oscillatorMNA2]
Out[31]//DisplayForm=
I$L1t C1 V$1 ′ t V$2 ′ t ⩵⩵ 0,
V$2t
C1 V$1 ′ t V$2 ′ t ⩵⩵ 0, V$1t L1 I$L1 ′ t ⩵⩵ 0,
R1
I$L10 ⩵⩵ 0, V$10 V$20 ⩵⩵ 0.002, V$1t, V$2t,
I$L1t, DesignPoint L1 0.00001, C1 3. 10 7 , R1 1.
Note that this time the time-domain equations contain not only the initial condition for the
capacitor C1 (given by the node voltage difference V$1[0] V$2[0]) but also an initial condition for
the inductor current I$L1[0]. Now, we compute the DC operating point and the transient response
by applying NDAESolve.
Finally, we plot the output current.
In[32]:= NDAESolve[oscillatorMNA2, {t, 0.}]
Out[32]= V$1 0.002, V$2 0., I$L1 0.
In[33]:= transient2 = NDAESolve[oscillatorMNA2, {t, 0., 10^−4}]
Out[33]=
V$1 InterpolatingFunction0., 0.0001, ,
V$2 InterpolatingFunction0., 0.0001, ,
I$L1 InterpolatingFunction0., 0.0001,
In[34]:= TransientPlot[transient2, {I$L1[t]}, {t, 0., 10^−4},
PlotRange −> All]
0.0002
0.0001
0.00002 0.00004 0.00006 0.00008 0.0001 t
I$L1[t]
-0.0001
-0.0002
-0.0003
Out[34]= Graphics
Please note the different transient waveforms dependent on the usage of initial conditions.