RC Transient

1
Example 5
PSPICE assumes the circuit in SS at t0-. We do
not need to provide initial value for the
capacitor.
RC Transient V1 1 0 DC 10V R1 1 2 2 C1 2 0
1/3 X1 2 3 Sw_tclose R2 3 4 6 V2 0 4 50 .Lib
Eval.lib .Tran 5m 5 0 5m .Probe .End
v
V(2,0)
TRACE EXPRESSION
i
I(R1)
15EXP(-2TIME)-5
For Verification
2
Example 6
PSPICE assumes the circuit in SS at t0-. We do
not need to provide initial value for the
inductor.
RL Transient I1 0 1 DC 3A R1 1 0 10 L1 1 2
1.5H X1 2 0 Sw_topen R2 2 0 5 .Lib Eval.lib .Tran
5m 5 0 5m .Probe .End
2
1
L1
i(0) 3A
R2
R1
I1
0
v
V(2,0)
TRACE EXPRESSION
i
I(L1)
2EXP(-10TIME)
For Verification
3
Example 3
t 0
1
i
t t
2
1k
20 V
100 V
0.5 mF
Find i(t) for t gt0.
Plot i(t) for t gt0.
4
Question For Example 3
The switch in the circuit of Figure Example 3 has
been opened for a long time. At t 0, the switch
is moved to position 1. The switch remains at
position 1 for t s then moved to position 2 at t
t s. Assume no initial charge at t 0. Find
i(t) for t gt 0. Plot i(t) for t gt0.
5
PSpice Input File (Netlist)
RC time with delay V1 1 0 DC 100V X1 1 2 SW_topen
PARAMS topen0.5m X2 2 3 SW_tclose PARAMS
tclose0 X3 3 4 SW_topen PARAMS topen0 X4 3 4
SW_tclose PARAMS tclose0.5ms V2 0 4 DC 20V R1 3
5 1k C1 5 0 0.5u .Lib Eval.lib .Tran 1u 5m 0
1u .Probe .End