ECET11
Lab Activity #6 Part 1
Given the circuit below:
Enzo Paterno
Students: __________________________________
__________________________________
Construct the circuit shown below:
R << XL given the operating frequency so that V A ≈ VL
Digital Storage Oscilloscope
IR = IL
VS
6 VPP
10 kHz
≈ VL
L
10 mH
R
47 Ω
VR
1
ECET11
Lab Activity #6 Part 1
Enzo Paterno
Students: __________________________________
__________________________________
VR and IR are in phase and IR = IL. Thus, VR and IL are in phase. The oscilloscope
waveforms represent the phase relationship between VL and IL .
Draw the Channel 1
and Channel 2
waveforms.
Measure the phase
difference between
the two waveforms.
t
θ = 360°
T
θ = _________
2
ECET11
Lab Activity #6 Part 2
Given the circuit below:
Enzo Paterno
Students: __________________________________
__________________________________
Construct the circuit shown below:
Digital Storage Oscilloscope
Measure VR (Pk-Pk) for various frequencies
(10 kHz, 20 kHz, 40 kHz, 60 kHz, 80 kHz,
100 kHz) and record your
answers in the table provided
on page 5.
VS
8 VPP
10 kHz
CH1
L
10 mH
R
1 kΩ
VRmeasured
3
ECET11
Lab Activity #6 Part 2
Given the circuit below:
Enzo Paterno
Students: __________________________________
__________________________________
Construct the circuit shown below (i.e. Reverse the components):
Measure VL (Pk-Pk) for various frequencies
(10 kHz, 20 kHz, 40 kHz, 60 kHz, 80 kHz,
100 kHz) and record your
answers in the table provided
on page 5.
Digital Storage Oscilloscope
CH1
VS
8 VPP
10 kHz
R
1 kΩ
L
10 mH
VLmeasured
4
ECET11
Lab Activity #6 Part 2
Enzo Paterno
Students: __________________________________
__________________________________
measured
VRVmeasured
R
I TVmeasured
R
computed
VLmeasured
 Using Ohm’s law compute ITmeasured (i.e. VRmeasured / R) for the circuit at each frequency
and enter your values In the table above.
 Using the measured values of VLmeasured and the values of ITmeasured compute XL for
each frequency and enter your results in the table above.
 Compute XL for each frequency using the equation XL = 2π f L and enter your results
5
in the table above.
ECET11
Lab Activity #6 Part 3
Enzo Paterno
Students: __________________________________
__________________________________
Plot the two values of XL (for
each frequency) for the
last two columns
6
ECET11
Lab Activity #6 Part 4
Given the circuit below:
Enzo Paterno
Students: __________________________________
__________________________________
Construct the circuit shown below:
Trigger on Channel 1. Measure VR(pk-pk) and record
the measurement on Part 6 table.
θR relative to VS can be determined using:
θ=
Digital Storage Oscilloscope
t
360°
T
T = Period
t = time between the
points where the 2
waveforms cross the
t-axis.
Record the computation
on Part 6 table.
VS
VS
8 VPP
20 kHz
L
10 mH
R
1 kΩ
VR
7
ECET11
Lab Activity #6 Part 5
Given the circuit below:
Enzo Paterno
Students: __________________________________
__________________________________
Construct the circuit shown below:
Trigger on Channel 1. Measure VL(pk-pk) and record
the measurement on Part 6 table.
θL relative to VS can be determined using:
θ=
Digital Storage Oscilloscope
t
360°
T
T = Period
t = time between the
Points where the 2
waveforms cross the
t-axis.
Record the computation
on Part 6 table.
R
1 kΩ
VS
VS
8 VPP
20 kHz
L
10 mH
VL
8
ECET11
Lab Activity #6 Part 6
Enzo Paterno
Students: __________________________________
__________________________________
Frequency
VR
θR
VL
θL
20 kHz
45 kHz
90 kHz
180 kHz
350 kHz
 Measurement results for: VR and VL (Peak-Peak)
 Computations for θR and θL relative to VS
9
ECET11
Lab Activity #6 Part 7
Enzo Paterno
Students: __________________________________
__________________________________
Frequency
VS = V + V
2
R
2
L
 VL 

 VR 
θ S = tan −1 
20 kHz
45 kHz
90 kHz
180 kHz
350 kHz
 Use the data from Part 6 table to calculate the magnitude and phase angle of
VS and enter the results in the Part 7 table.
10
ECET11
Lab Activity #6 Part 8
Enzo Paterno
Students: __________________________________
__________________________________
+ 90 º
+ 90 º
+ 45 º
+ 90 º
+ 45 º
0º
0º
-45 º
- 90 º
20 kHz
+ 45 º
0º
-45 º
-45 º
- 90 º
- 90 º
90 kHz
350 kHz
 Use the results from Part 6 and Part 7 tables to draw the voltage phasor
diagrams for VR, VL, and VS at frequencies of 20 kHz, 90 kHz and 350 kHz.
11