To investigate several diode applications namely clipping circuits, peak detectors, clamping circuits and voltage doublers.
To investigate several diode applications namely clipping circuits, peak detectors, clamping
circuits and voltage doublers.
LAB PROCEDURE
Clipping circuit
a. Construct the clipping circuit shown in Figure 1. Using a dual channel oscilloscope
obtain the input and output waveforms. Note that the function generator in Figure 1 is
set to output units of “rms” and not “pk-pk”. Make sure that both channels are
synchronized in terms of the gain settings (V/Div) and zero volt reference axis.
b. Construct the clipping circuit with a reference voltage source as shown in Figure 2.
Obtain a screen capture of the waveforms illustrating the clipping phenomenon with the
reference voltage source indicated as V2 in Figure 2.
REPORT: Explain the impact of the reference voltage V2 on the output waveform. Explain
why the output waveforms were as observed, using the conditions required to forward bias
and to reverse bias the diodes as the basis for the explanation.
University of Dayton, Department of Electrical and Engineering Department, Spring 2017
V1
3 Vrms
1kHz
0°
D1
1N4148
R1
1kΩ
XSC1
Agilent
0
3
1
Figure 1: Clipping circuit
V1
3 Vrms
1kHz
0°
V2
2 V
D1
1N4148
R1
1kΩ
XSC1
Agilent
3
0
1
2
Figure 2: Clipping circuit with reference voltage source
Peak Detector
a. Construct the peak detector circuit shown in Figure 3. The idea behind such a design is
to charge the capacitor up to peak voltage of the input and to refresh it with each cycle
before discharge occurs. Using a dual channel oscilloscope in the dc-coupled mode,
obtain a screen capture of the input and output waveforms. Note that you may or may
not have to change the capacitor value if the capacitor appears to discharge too
quickly. Whatever value of capacitor you use, be sure to maintain that value for the
entire exercise in this sub-section. Also please confirm the capacitance value by
reading it off the body of the capacitor or double-checking with the capacitance meter.
Include this information in your formal report.
b. Moreover, investigate the effect of adding a load resistance across the output as
shown in Figure 4. Obtain a screen capture that demonstrates such an effect with load
resistances of 390Ω, 56KΩ and a 2.2MΩ and explain the changes you observe.
REPORT: How can you explain the changes in the observed output waveform when adding a
load?
University of Dayton, Department of Electrical and Engineering Department, Spring 2017
V1
3 Vrms
1kHz
0°
D1
1N4148
XSC1
Agilent
C1
100nF
1
0
2
Figure 3: Peak detector circuit
V1
3 Vrms
1kHz
0°
R1
D1
1N4148
C1
100nF
XSC1
Agilent
0
1 2
Figure 4: Peak detector circuit with load
Clamping circuit
a. Construct the clamping circuit as shown in Figure 5. Using a dual channel oscilloscope in
the dc-coupled mode (Mode/Coupling button), obtain a screen capture of the input and
output waveforms.
b. Repeat (a) for the clamping circuit containing the reference voltage source shown in Figure
6.
REPORT : Explain the operation of either one of the clamping circuits.
University of Dayton, Department of Electrical and Engineering Department, Spring 2017
V1
3 Vrms
1kHz
0°
XSC1
Agilent
C1
100nF
D1
1N4148
0
1
3
Figure 5: Clamping circuit
V1
3 Vrms
1kHz
0°
XSC1
Agilent
C1
100nF
D1
1N4148
V2
2 V
2
0
3
1
Figure 6: Clamping circuit with reference voltage source
Voltage Doubler
a. Construct the voltage doubler show in Figure 7. Note that the ‘doubler’ can be seen as a
clamp cascaded/followed by a peak detector. Obtain the input and output waveforms of
the voltage doubler circuit.
b. Connect several different load resistors as shown in Figure 8 and obtain the corresponding
screen captures. Use load resistors of 390Ω, 56KΩ and 2.2MΩ.
REPORT : Explain the operation of the voltage doubler circuit.
University of Dayton, Department of Electrical and Engineering Department, Spring 2017
V1
3 Vrms
1kHz
0°
D1
1N4148
D2
1N4148
C1
100nF
C2
100nF
2
0
XSC1
Agilent
1 3
Figure 7: Voltage Doubler
V1
3 Vrms
1kHz
0°
D1 R1
1N4148
D2
1N4148
C1
100nF
C2
100nF
2
XSC1
Agilent
1
0
3
Figure 8: Voltage Doubler with load
General notes:
A formal write up is required. Refer to the Guidelines for Writing a Formal Report and the
template provided on Isidore.
Prepare a typed up report. Submit a pdf of your report on Isidore.
Include ALL simulation results and screen captures in your report. Also be sure to include
answers to all items marked REPORT in the formal lab procedure above