Lab 2 Report – DC and AC Analysis with PSpice Software
Bill Chun Wai Hung
A.
Describe the Set-up
There are two circuits that were investigated in this lab. One is a DC circuit analysis and the other is an AC circuit analysis. The set-up diagram and the source file for the PSpice software is shown below. In the diagrams, R is resistors, V is voltage source, C is capacitors, and D is diode
*this is my DC circuit
* Circuit Diagram
* 1--------(R1)-----2
* | |
* | |
*(V0) (R2)
* | |
* | |
* -----------------0 (Ground)
R1 1 2 1k
V0 1 0 5
R2 2 0 1k
.DC V0 0 5 1.0
*DC element start stop step
.PLOT DC V(1,0)
.END
Part II. AC Circuit Analysis
AC Circuit Analysis
*this is my AC circuit
R1 1 2 1k
V0 1 0 AC 1
*element Node+ Node- AC Amplitude sin(off-set, amplitude, frequence)
C1 2 0 1u
* 1--------(R1)----2
* | |
* | |
*(V0) (C1)
* | |
* | |
* ------------------0 (Ground)
.AC LIN 20 1 60000Hz
*AC Linear #-of-points Start Stop
.PLOT AC V(2, 0)
.END
Part III. Tran Analysis
TRAN Circuit Analysis
R1 1 2 1k
V0 1 0 AC 1 sin(0 1 10MEG)
*element Node+ Node- AC Amplitude sin(off-set amplitude frequence)
C1 2 0 1u
* Circuit Diagram
* 1--------(R1)-----2
* | |
* | |
*(V0) (C1)
* | |
* | |
* -----------------0 (Ground)
.TRAN 1n 100n
*TRAN time-step Stop-time (start-time), in this case, 1 nano-second step add up to 10 micro second
.PLOT TRAN V(2, 0)
.END
B.
Desbribe Inputs
In the DC Circuit, there are 2 resistors
each of 1 kilo ohms, 1 voltage source of 5 volt. The voltage across node 0 and
1 is measured, that is the voltage across resistor 1 and resistor 2 (R1 and
R2).
Part II. AC Circuit Analysis
In the AC Circuit, the set-up is similar to
the set-up in the Part I (See the diagram in Part A), except the resistor (R2)
is replaced by a capacitor (C1) across node 2 and node 0. The voltage across
node 0 and node 2 is measured, that is the voltage across the capacitor (C1).
Part III. Tran Analysis
In the transient analysis, the voltage
source has defined a signal frequency by sin (0 1 10MEG), which means a sine
function of frequency 10 mega herz, no offset, and with an amplitude of 1.
C.
Describe What you Observe
The output is consistent with the input. The input voltage of the voltage source is 5 volt, and the voltage across resistor 1 and 2 (R1 and R2) is also 5 volts. This is consistence ohm’s law of V=IR.
From the graph of simulation, the voltage drop across node 1 and node 0 can be seen. This diagram shows a linear voltage drop, and this is consistent with the ohms law V=IR for a circuit that consist of resistors (R1 and R2) and voltage source.
Diagram of Simulation for
V0 V(1,0)
(*)---------- 0.0000E+00 2.0000E+00 4.0000E+00 6.0000E+00 8.0000E+00
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
0.000E+00 0.000E+00 * . . . .
1.000E+00 1.000E+00 . * . . . .
2.000E+00 2.000E+00 . * . . .
3.000E+00 3.000E+00 . . * . . .
4.000E+00 4.000E+00 . . * . .
5.000E+00 5.000E+00 . . . * . .
- - - - - - - - - - - - - - - - - - - - - - - - - - -
Part II. AC Circuit Analysis
The result of the AC Circuit shows the
behavior of a RC (Resistor and Capacitor) circuit. The graph shows the
relationship between voltage and frequency.
Diagram of Simulation
for Part II. AC Circuit Analysis
FREQ V(2,0)
(*)---------- 1.0000E-03 1.0000E-02 1.0000E-01 1.0000E+00 1.0000E+01
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
1.000E+00 1.000E+00 . . . * .
3.159E+03 5.032E-02 . . * . . .
6.317E+03 2.519E-02 . . * . . .
9.475E+03 1.680E-02 . . * . . .
1.263E+04 1.260E-02 . . * . . .
1.579E+04 1.008E-02 . .* . . .
1.895E+04 8.399E-03 . * . . .
2.211E+04 7.199E-03 . *. . . .
2.526E+04 6.300E-03 . * . . . .
2.842E+04 5.600E-03 . * . . . .
3.158E+04 5.040E-03 . * . . . .
3.474E+04 4.582E-03 . * . . . .
3.790E+04 4.200E-03 . * . . . .
4.105E+04 3.877E-03 . * . . . .
4.421E+04 3.600E-03 . * . . . .
4.737E+04 3.360E-03 . * . . . .
5.053E+04 3.150E-03 . * . . . .
5.368E+04 2.965E-03 . * . . . .
5.684E+04 2.800E-03 . * . . . .
6.000E+04 2.653E-03 . * . . . .
- - - - - - - - - - - - - - - - - - - - - - - - - - -
Part III. Tran Analysis
The graph of transient is shown below. This
is a plot of the voltage across the capacitor (between node 2 and node 0), from
time equals to zero to time equals to 100 nanoseconds. The time step (interval
of time) is 1 nanosecond. The voltage function is a sine function defined by
the voltage source (sin(0 1 10MEG)).
Diagram of Simulation
for Part III. Tran Analysis
TIME V(2,0)
(*)---------- -2.0000E-05 0.0000E+00 2.0000E-05 4.0000E-05 6.0000E-05
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
0.000E+00 0.000E+00 . * . . .
1.000E-09 3.464E-08 . * . . .
2.000E-09 1.381E-07 . * . . .
3.000E-09 3.028E-07 . * . . .
4.000E-09 5.242E-07 . * . . .
5.000E-09 7.985E-07 . .* . . .
6.000E-09 1.140E-06 . .* . . .
7.000E-09 1.532E-06 . .* . . .
8.000E-09 1.989E-06 . .* . . .
9.000E-09 2.492E-06 . . * . . .
1.000E-08 3.057E-06 . . * . . .
1.100E-08 3.664E-06 . . * . . .
1.200E-08 4.327E-06 . . * . . .
1.300E-08 5.029E-06 . . * . . .
1.400E-08 5.780E-06 . . * . . .
1.500E-08 6.564E-06 . . * . . .
1.600E-08 7.392E-06 . . * . . .
1.700E-08 8.247E-06 . . * . . .
1.800E-08 9.138E-06 . . * . . .
1.900E-08 1.005E-05 . . * . . .
2.000E-08 1.099E-05 . . * . . .
2.100E-08 1.195E-05 . . * . . .
2.200E-08 1.292E-05 . . * . . .
2.300E-08 1.390E-05 . . * . . .
2.400E-08 1.490E-05 . . * . . .
2.500E-08 1.589E-05 . . * . . .
2.600E-08 1.689E-05 . . * . . .
2.700E-08 1.788E-05 . . *. . .
2.800E-08 1.887E-05 . . *. . .
2.900E-08 1.984E-05 . . * . .
3.000E-08 2.080E-05 . . .* . .
3.100E-08 2.174E-05 . . .* . .
3.200E-08 2.265E-05 . . . * . .
3.300E-08 2.354E-05 . . . * . .
3.400E-08 2.440E-05 . . . * . .
3.500E-08 2.522E-05 . . . * . .
3.600E-08 2.601E-05 . . . * . .
3.700E-08 2.676E-05 . . . * . .
3.800E-08 2.746E-05 . . . * . .
3.900E-08 2.812E-05 . . . * . .
4.000E-08 2.873E-05 . . . * . .
4.100E-08 2.930E-05 . . . * . .
4.200E-08 2.980E-05 . . . * . .
4.300E-08 3.026E-05 . . . * . .
4.400E-08 3.065E-05 . . . * . .
4.500E-08 3.099E-05 . . . * . .
4.600E-08 3.126E-05 . . . * . .
4.700E-08 3.149E-05 . . . * . .
4.800E-08 3.164E-05 . . . * . .
4.900E-08 3.174E-05 . . . * . .
5.000E-08 3.176E-05 . . . * . .
5.100E-08 3.174E-05 . . . * . .
5.200E-08 3.164E-05 . . . * . .
5.300E-08 3.149E-05 . . . * . .
5.400E-08 3.126E-05 . . . * . .
5.500E-08 3.099E-05 . . . * . .
5.600E-08 3.065E-05 . . . * . .
5.700E-08 3.026E-05 . . . * . .
5.800E-08 2.980E-05 . . . * . .
5.900E-08 2.930E-05 . . . * . .
6.000E-08 2.873E-05 . . . * . .
6.100E-08 2.812E-05 . . . * . .
6.200E-08 2.746E-05 . . . * . .
6.300E-08 2.676E-05 . . . * . .
6.400E-08 2.601E-05 . . . * . .
6.500E-08 2.522E-05 . . . * . .
6.600E-08 2.440E-05 . . . * . .
6.700E-08 2.354E-05 . . . * . .
6.800E-08 2.265E-05 . . . * . .
6.900E-08 2.174E-05 . . .* . .
7.000E-08 2.080E-05 . . .* . .
7.100E-08 1.984E-05 . . * . .
7.200E-08 1.887E-05 . . *. . .
7.300E-08 1.788E-05 . . *. . .
7.400E-08 1.689E-05 . . * . . .
7.500E-08 1.589E-05 . . * . . .
7.600E-08 1.490E-05 . . * . . .
7.700E-08 1.390E-05 . . * . . .
7.800E-08 1.292E-05 . . * . . .
7.900E-08 1.195E-05 . . * . . .
8.000E-08 1.099E-05 . . * . . .
8.100E-08 1.005E-05 . . * . . .
8.200E-08 9.136E-06 . . * . . .
8.300E-08 8.247E-06 . . * . . .
8.400E-08 7.390E-06 . . * . . .
8.500E-08 6.564E-06 . . * . . .
8.600E-08 5.778E-06 . . * . . .
8.700E-08 5.028E-06 . . * . . .
8.800E-08 4.325E-06 . . * . . .
8.900E-08 3.663E-06 . . * . . .
9.000E-08 3.055E-06 . . * . . .
9.100E-08 2.491E-06 . . * . . .
9.200E-08 1.987E-06 . .* . . .
9.300E-08 1.531E-06 . .* . . .
9.400E-08 1.138E-06 . .* . . .
9.500E-08 7.971E-07 . .* . . .
9.600E-08 5.225E-07 . * . . .
9.700E-08 3.013E-07 . * . . .
9.800E-08 1.492E-07 . * . . .
9.900E-08 4.364E-08 . * . . .
1.000E-07 -1.373E-09 . * . . .
- - - - - - - - - - - - - - - - - - - - - - - - - - -
D.
What you can deduce
From the observation in Part C, the linear
drop of the voltage represents the linear voltage drop caused by resistors.
Part II. AC Circuit Analysis
From the observation in Part C, the voltage
drop shows as the frequency increases, the voltage across the capacitor
decreases. The decrease of the voltage is in a
exponential form.
Part III. Tran Analysis
From the observation in Part C, the voltage
of the capacitor increases and decreases according to the input voltage of the
voltage source (V0).The voltage of the capacitor is observed by the transient
plot, which is the voltage of the capacitor against time.