This document provides instructions for a lab experiment on DC circuit analysis using PSpice simulation software. The experiment involves constructing circuits with independent and dependent sources and analyzing their DC characteristics by sweeping source voltages and currents. Key steps include plotting diode voltage and current under DC sweep, determining maximum power dissipation of a resistor under parametric sweep, and calculating the Thévenin equivalent circuit and current. The document also discusses DC analysis, dependent sources, parametric analysis, and methods for determining maximum power dissipation.

1. Centre of Diploma Studies Page 1/6
Electrical Engineering Department Session 2010/2011
Experiment’s Title: DC Analysis Semester II
CENTRE OF DIPLOMA STUDIES
COMPUTER AIDED DESIGN LABORATORY
LABORATORY INSTRUCTION SHEET
Subject’s Code DEE 2213 / DAE 21503
Experiment’s Title DC ANALYSIS
Course’s Code 2 DEE/DET/DAE
No. of Experiment 4

2. Centre of Diploma Studies Page 2/6
Electrical Engineering Department Session 2010/2011
Experiment’s Title: DC Analysis Semester II
AIM: To provide understanding in DC transfer characteristic.
1.0 OBJECTIVES
1. To be able to the DC Sweep mode of operation.
2. To be able to use markers for convenient trace variable display.
2.0 OVERVIEW
The DC sweep analysis causes a DC sweep to be performed on the circuit. DC sweep
allows you to sweep a source (voltage or current), a global parameter, a model
parameter, or the temperature through a range of values. The bias point of the circuit is
calculated for each value of the sweep. This is useful for finding the transfer function
of an amplifier, the high and low thresholds of a logic gate, and so on.
R 1
Vd
1k
V
V1
0Vdc D 1
D 1N 914
0 0
DC sweep for the above figure is to analyze the voltage barriers for diode 1N914 as
source voltage, V1 varies from -15V to 15V. Normally, plotted graphs depend on type
of analyses used. In this case x-axis is voltage source variations and y-axis is diode
voltage, as in figure below.
5V
0V
-
5V
- V
10
-
15V
-
15V - V
10 -
5V 0V 5V 10V 15V
V D)
(V
V 1
_V

3. Centre of Diploma Studies Page 3/6
Electrical Engineering Department Session 2010/2011
Experiment’s Title: DC Analysis Semester II
To check diode voltage barrier, plotted graph should be I(diode) vs V(diode). To
change x-axis into I(diode), select Axis setting → X-axis → Axis Variable, and select
diode current. I(diode) vs V(diode) graph should be as figure below.
5V
0V
-
5V
- V
10
-
15V
0A 2mA 4mA 6mA 8mA 10mA 12mA 14mA 16mA
V D)
(V
I(D1)
PSpice allows one to vary a parameter and to evaluate its effects on the dc analysis.
The parameters could be a circuit element such as R, L, C and their model parameter.
The sweep variable name can be one of the following:
Source. A name of an independent voltage or current source. During the sweep, the
source’s voltage or current is set to the sweep value
Model parameter. A model type name and then a model name followed by a model
parameter name in parenthesis. The parameter in the model is set to the sweep value.
Temperature. The keyword TEMP followed by the keyword LIST. The temperature
is set to the sweep value. For each value of sweep, the model parameters of all circuit
components are updated to that temperature.
Global parameter. The keyword PARAM followed by a parameter name. The
parameter is set to sweep. During the sweep, the global parameter’s value is set to the
sweep value and all expressions are evaluated.

4. Centre of Diploma Studies Page 4/6
Electrical Engineering Department Session 2010/2011
Experiment’s Title: DC Analysis Semester II
3.0 EQUIPMENT LIST:
1. Personal Computer
2. OrCAD Capture CIS
3. OrCAD Pspice A/D
4. Storage Device
4.0 PROCEDURE:
1. Reconstruct circuit in Figure 4.1 into PSpice equivalent circuit.
a. Print out the PSpice equivalent circuit diagram.
b. Sweep the current source from 0A to 3A with 0.1A increment.
c. Plot power delivered at 8Ω resistor
d. Get the power delivered when current is at 1.8A
e. Print out graph from (d).
f. Add another plot window to trace V(in) vs V(load).
g. Get the value of V(load) when V(in) is at 10V.
h. Print out graph form (g).
in load
2
+
I12 A V1 V1
A
4 4 8
-
Figure 4.1
Important Note: When assigning the gain in dependent source, ensure it is in decimal
form instead of fractional form ( e.g : set gain to 0.25 instead of 1/4)

5. Centre of Diploma Studies Page 5/6
Electrical Engineering Department Session 2010/2011
Experiment’s Title: DC Analysis Semester II
2. Construct circuit as in Figure 4.2:
a. Print out the Pspice equivalent circuit
b. Replace the RL resistor with the suitable model for parametric analysis.
c. Sweep the RL from 1Ω to 30Ω with 1Ω increments.
d. Plot the power (watt) dissipated in RL.
e. Get the maximum power dissipated by RL.
f. Print out graph from (e).
g. Get the value of Thèvenin Resistance (RTH) with RL as output terminal.
h. Print out output file for (g).
4 12
i1
V1
3i1 V
3V R L
Figure 4.2
5.0 ANALYSIS
1. From graph 4.1e; what is the power delivered at 8Ω when input current is at 1.8A.
(3 marks)
2. What is V(load) value accumulated form graph from graph 4.1h.
(3 marks)
3. Make a conclusion from plotted graph in procedure 4.1h.
(3 marks)
4. Make a conclusion from graph 4.2e.
(4 marks)
5. From 4.2h, get the Thèvenin equivalent circuit.
(4 marks)
6. From 5.5, calculate total current during maximum power dissipation of RL.
(3 marks)

6. Centre of Diploma Studies Page 6/6
Electrical Engineering Department Session 2010/2011
Experiment’s Title: DC Analysis Semester II
6.0 DISCUSSION
1. Discuss dc analysis (.DC) in general.
(5 marks)
2. Discuss how dependent sources are translated into PSpice equivalent circuit in this
exercise.
(5 marks)
3. Discuss parametric analysis in general.
(5 marks)
4. Discuss two methods introduced in this experiment in determining maximum power
dissipation.
(5 marks)
7.0 CONCLUSION
Make a conclusion form the listed topics.
1. DC analysis (.DC) simulation for electrical circuit.
(5 marks)
2. Independent and dependent sources adaptation in PSpice equivalent circuit.
(5 marks)
3. Parametric analysis (.PARAM) simulation for electrical circuit.
(5 marks)
8.0 REPORT WRITING
Report writing can be written in English or Malay.
Report writing must be handwritten and submitted at the end of lab session.
Report can be submitted in a group of two.
Group reporting consists of individual results (print out), individual analysis, group
discussion and group conclusion.