ECE 213 Electrical Circuits Lab II
LAB #9
Fall 2013
Name ___________________
Section ______________
Introduction to AC Simulation
OBJECTIVE:
Each student will be able to use: (a) Simulation program to determine voltage and current
amplitudes and phase angles in an AC circuit, and (b) the AC sweep capability of the simulation
program to compute and plot the frequency response of a circuit.
COMPONENTS AND EQUIPMENT:
1.
2.
3.
4.
5.
Oscilloscope
Function Generator
Digital Multimeter
Personal Computer
Simulation Program (PSPICE, LTSPICE (free), Cadence, TINA)
PROCEDURE:
1. Single-Frequency Analysis:
The circuit has L = 210 mH, R = 1 kΩ, C = 480 nF, and the
sinusoidal source shown in the figure is described by the
equation:
vg = 3sin(2πf t) V
where f = 1 kHz
Figure 1 - Circuit Diagram
(a) The voltage 3V is the amplitude of voltage (Vpeak = 3V). Solve the circuit by finding
voltages on each node, voltage across each component, and the current across the circuit.
Show all the calculation. Then Find out real and reactive power in each component. Use
amplitude voltage for calculation.
(b) Use simulation to find the magnitude and phase of each node, VL, VR, VC (across
component), and the current in the series circuit;
(c) Check the simulation results against an analytical solution. Report percent error.
(d) Construct the circuit and measure the voltage on each node including phase, voltage and
phase across L, R, and C, and current. Capture the waveform from Oscilloscope. Tabulate the
result in the report. If possible, take a picture of the constructed circuit.
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ECE 213 Electrical Circuits Lab II
LAB #9
Fall 2013
A schematic representation of this circuit is shown below.
N1
N2
N3
Figure 2 - Circuit Schematic
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ECE 213 Electrical Circuits Lab II
LAB #9
Fall 2013
2. Swept Frequency Analysis Part A: AC Sweep
Place Node 1, 2, 3… on all the connector between each component.
(a) Place voltage marker on the node 2 and 3. Select AC Sweep as the type of analysis. Since
we only need a single frequency, set the Start and End “sweep” frequencies to the same value
and Number of Total Points to 1. Screen shot the node voltage. Note that we must specify
the source file frequency in Hertz.
(b) Then set the Number of Total Point to 100, frequency from 10Hz to 2kHz. Sweep and plot
the Voltage node, voltage across R, L, and C. Capture the waveform with results shown in
the plot. Label the node voltage at 1kHz. Does the value agree to calculation?
(c) Find out the resonant frequency of the circuit at VR (Voltage acorss R) by plotting a range of
frequency. The resonant frequency is frequency where voltage is at peak.
(d) Output the simulation values and open them in a spreadsheet. Values can be saved in either
Rectangular or Polar form.
(e) Put a portion of this output into your lab book.
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ECE 213 Electrical Circuits Lab II
LAB #9
Fall 2013
3. Parametric Analysis
This part is to vary the R1 in several difference values. Change the schematic by replacing the
value of R with a "global parameter" named r_value contained in curly brackets: {r_value}; the
curly brackets are used to indicate a global parameter. “r_value” can be x, y, z. It’s just a
variable. Find the part call “PARAM”. The default value of such a parameter is specified using
the part named PARAM. Double click the PARAM part to specify a default value of r_value; do
not use the curly brackets here. Set the default value of r_value to 1 kΩ, the original value of R.
During a swept frequency analysis, a global parameter can also be swept using a "parametric
sweep". Examine the Parametric option under Options and notice the type of information
required to specify the Sweep Variable Type and Sweep Type. List the possible Sweep Variable
Types and the possible Sweep Types.
Use what you have just learned about AC Sweep analysis and about parametric sweeps to
examine the effect of the resistor value on the magnitude response. Use the following list of
values (Use List Value in configuration): 500 Ω, 1 kΩ, 2k, and 5 kΩ. Label the results at 1kHz.
Paste the waveform in your report. Example of a schematic is shown below. Plot Vout (Node 3:
between R and C). Capture the waveform.
Figure 3 – Example: AC Sweep with Parametric Analysis
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ECE 213 Electrical Circuits Lab II
LAB #9
Fall 2013
Figure 4 - Parametric Analysis
QUESTIONS:
1.
2.
3.
4.
5.
Explain what AC Sweep is and the usage of it.
Explain what Transient Analysis is.
Explain the Parametric Analysis
What is the voltage between the inductor and resistor at 0.6kHz from simulation?
Think of an application where you will need to use RLC circuit.
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