ECET210 Week 2 iLab3 Complete Solution
Laboratory Procedures
DeVry University
College of Engineering and Information Sciences
I.OBJECTIVES
To analyze a series AC circuit containing an inductor (L) and a resistor (R) using Ohm’s Law and Kirchhoff’s Voltage Law.
To simulate the RL circuit and observe the voltage drops and currents at different frequencies.
To build a RL circuit and measure voltage drops and current at different frequencies.
To prove that the power delivered by the source is equal to the sum total of power dissipated by all of the resistors in the circuit.
Equipment:
Function Generator
DMM (Digital Multimeter)
Parts:
1 - 470 Ω Resistor 1 - 47 mH Inductor
Software;
MultiSim 11
A. Theoretical Analysis
Given the R & L series circuit in Figure 1, calculate the total equivalent impedance, ZT , of the circuit at frequencies, f = 1 kHz, 2kHz and 3 kHz, and list the values obtained in Table 1.
Figure 1: Series R L Circuit
Note: Notice that the self resistance, RL of the 47 mH inductor is shown in the schematic. This should be included in the analysis, as it is present with the inductor, since the inductor is a wire-wound component. Before starting the lab, measure the coil resistance with a DMM and include the value in the ensuing calculations.
Frequency (kHz) | Reactance, XL (Ω) | Inductive Impedance ZL | Total Series Circuit Impedance ZT | ||
Rectangular Form RL + j XL | Rectangular Form [R + RL] + jXL | Magnitude | Angle | ||
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Table 1 – RL Circuit-Calculated Impedance Values
Calculate and record the following quantities:
Frequency (kHz) | IS (RMS) = VS / ZT (A) | Power Factor | ||
Rectangular Form | Magnitude | Angle |
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Table 2 – RL Circuit-Calculated Current Values
Frequency (kHz) | VL (RMS) – (Volts) | ||
Rectangular Form | Magnitude | Angle | |
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Table 3 – RL Circuit-Calculated Inductor Voltage Values
Frequency (kHz) | VR (RMS) - (Volts) | {VL + VR}(RMS) - (Volts) | ||
Rectangular Form | Magnitude | Angle | ||
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Table 4 – RL Circuit-Calculated Voltage Values
Does the sum of the 2 voltage drops in Table 4 equal 2.5 VRMS ?
(YES or NO)
Explain why your answer is what it is.
Calculate the power dissipated in the series resistor of this circuit and the power supplied by the source:
Frequency (kHz) | PR (W) | PS (W) |
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Table 5 - Source Power and Power Dissipation
B. MultiSim Simulation and Circuit Calculations
Launch MultiSim and build the circuits shown in Figure 2. Include the AC power source and connect the DMMs.
Figure 2 – MultiSim RL Circuit with Instrumentation
The MultiSim AC power source has the facility to choose RMS value for the voltage in addition to frequency and the phase. Type 2.5 in the voltage window of the power-source dialog box.
Choose any one frequency (1kHz, 2 kHz, or 3 kHz) for the source used in Section A. In Figure 2, a source frequency of 1 kHz is used.
Set both DMMs, XMM1 and XMM2, to read AC measurements and Voltage (V). Set the DMM, XMM3, to read AC RMS Current.
Expand the DMMs, activate the MultiSim simulation, and record the voltage and current readings in Table 5.
Frequency (kHz) | IS (RMS) | VL (RMS) | VR (RMS) (Volts) |
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Table 5 - MultiSim Simulation Results
Do the (simulated) voltage and the current values in Table 5 agree with those obtained in Tables, 2, 3, and 4 of Part A? (Circle your answer).
YES NO
Remove the DMMs from the circuit and enable the wattmeter from the instrument menu, as shown in Figure 3.
Figure 3 - AC Power Measurement with Wattmeter
Turn the simulator ON and note the Power in Watts and the Power Factor as displayed by the simulator wattmeter instrument.
Frequency (kHz) | Source Power, PS (Watts) | Power Factor |
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Table 6 - Power Measurement Readings
Do the numbers in Table 6 agree with those in Table 2?
YES NO
If there is any disagreement, investigate the source of error and report your findings below:
C. Construction of a Series R L Circuit and Measurement of Circuit Characteristics
Construct the circuit in Figure 1.
Set the function generator voltage to 2.5 V RMS. Set the frequency to the same value used in the simulator experiment.
Set DMM to measure AC current and make the appropriate connections. Switch the function generator power ON.
Record the current reading.
IS = _____________ (A)
Is this the same as the simulated and calculated value? ________ (YES or NO)
Switch OFF the AC input power. Remove the DMM and re-configure it to measure voltages. Reconnect the circuit and apply power. Measure the voltage across L and R, one at a time.
Record these voltages.
VL = ________ (V) VR = ________(V)
Are the voltage readings the same as your calculated and simulated values?
__________ (YES or NO)
If you answered NO, explain why you think they differ.
IV. TROUBLESHOOTING
Describe any problems encountered and how those problems were solved.
ECET210 Week 2 iLab3 Complete Solution
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