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AIM
This experiment was conducted in order to design and test the diode circuits for peak clipping
and peak detection
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It
does this by altering the positive peak or negative peak of the input signal to a definite value by
shifting the entire signal up or down to obtain the output signal peaks at the desired level
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As these circuits are only used for clipping input waveform as per requirement and
for transmitting the waveform, they do not contain any energy storing elements like capacitors
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Series clippers (Negative and positive clipping)
a
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The positive half of the input
waveform reverse biases the diode
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Resultantly providing no output voltage for
positive half of the input waveform

Figure A: Showing input and output for series positive clipper
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b
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This causing no current to flow through the circuit
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Figure B: Showing input and output for series negative clipper
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2
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Parallel positive clipper
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Hence its working principle is
exactly opposite of a series clipper
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Due to
this the parallel combination of the diode and the load, no current is observed at the
load
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The contrary,
during the negative half of the input signal, the diode gets reversed biased
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The entire half
appears at the output
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b
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For negative parallel clippers, during the positive half of input, the diode gets
reversed biased
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Hence the output signal is achieved fir positive half of the input signal
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Ultimately no output is observed for negative half
of the input signal
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3
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Hence the combination of a biased positive
clipper and a biased and a biased negative clipper is called a combination or dual diode
clipper
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Figure E: Showing input and output dual clipper circuits
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I No

Apparatus

Range

Quantity

1

AFO

2

VRPS Dual Supply

3

CRO

4

Resistors

10KΩ

4

5

Diodes

IN4007

5

6

Bread Board

6

7

Connecting wires

7

1
0 – 30 V

2
3

PROCEDURE

1
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Figure 1: Showing positive peak clipping

2
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3
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The AC voltage was gradually adjusted and the level of clipping was noted
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The input wave was connected to the other channel of the CRO and with the XY mode
the clipping characteristic was recorded
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Steps 1 to 5 were repeated for the circuits shown below
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Figure 6:Showing double ended clipper to generate ended clipper a symetrical square waves
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RESULTS AND DISCUSSIONS
After following every step stated above the following were the results obtained from the
experiment
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Figure 8 : Showing waveform for the input for all clipping circuits
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DIODE SHUNT CLIPPING ABOVE VR OR POSITIVE PEAK CLIPPING
(FIGURE (1))
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For the diode to
be forward biased it must have an input voltage greater than +2
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C source was added to the voltage of the diode (0
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4v) just
to increase the reference level of clipping
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Figure 9: Showing output waveform for diode shunt clipping above VR
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DIODE SHUNT CLIPPING BELOW VR OR NEGATIVE PEAK CLIPPING
(FIGURE (2))
After connecting the circuit in figure 2 it was noted that the diode (D1) was reversed
biased during the negative half cycle of the sinusoidal input wave form
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0 volts just because
the voltage of the D
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6v - 1
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Nothing happens to the positive side of the
wave
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3
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The negative side of the diode was connected to the positive part of the A
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C power supply
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C source (+2volts) the level of the blocked or removed part was
increased as shown in fig 11 below
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4
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The positive side of the diode was connected to the positive part of the A
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C power supply
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C source (-2volts)
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Figure 12: Showing output waveform for diode shunt clipping below VR
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CLIPPING AT TWO INDEPENDENT LEVELS OR SLICER CIRCUIT
(FIGURE (5))
After connecting the circuit in figure 5 it was noted that the diode (D1) was forward
biased during the positive half cycle of the sinusoidal input wave form
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0volts just because
the voltage of the D
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6v + 3
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diode (D2) was
reversed biased, the clipping happened on the negative half cycle of the wave but due
to the presence of VR2 (-1
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Figure 13: Showing output waveform for diode shunt clipping above VR
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DOUBLE ENDED CLIPPER TO GENERATE A SQUARE WAVE (FIGURE
(6))
From circuit in figure (6) diode (D1) was in reverse biased with battery (VR1) but in
forward biased from the voltage supply and diode (D2) was in reverse bias with the
battery but in forward bias with the voltage supply
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diode (D1) was responsible for clipping
on the positive part and diode (D2) on the negative part
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Figure 14: Showing output waveform for diode shunt clipping above VR
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CLIPPING CIRCUITS TO CLIP THE CENTER PORTION AND TRANSMIT
THE EXTREMITIES OF SINUSOIDAL SIGNAL (FIGURE (7))

Connection from circuit in figure (7) was showing that diode (D1) was reverse biased
by the input supply, the input wave form was clipped with the reference level of -2
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During the
negative half cycle diode D2 was forward biased by both the input supply voltage and
battery voltage as a result the negative half cycle was removed at the output with
reference level of clipping +2
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Due to the change of polarity of the A
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The bottom part had a smaller clip than the top due to
the magnitude of the batteries as shown in fig 15 below
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TRANSFER CHARACTERS
1
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From the experiment it was noticed that when voltage was below +1
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8 volts
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6

2
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8 there was no clipping
unless the voltage was below -1
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5
4
3

Y-Axis

2
1
0
-6

-4

-2

0

2

4

6

-1
-2
-3

Axis Title
Figure 17: Showing transfer characteristics of circuit 2
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DIODE SERIES CLIPPING ABOVE VR OR POSITIVE PEAK CLIPPING
(FIGURE (3))
From the lab it was noticed that when voltage was below +1
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6 volts
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4
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9 there was no clipping
unless the voltage was below -1
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5
4
3

Y-Axis

2

-6

1
0
-4

-2

-1 0

2

4

6

-2
-3

X-Axis

Figure 19: Showing transfer characteristics of circuit 4
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CLIPPING AT TWO INDEPENDENT LEVELS OR SLICER CIRCUIT
(FIGURE (5))
It was notice that clipping was happening when the supply voltage was below +1
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8

9
8
7
6

Y-axis

5
4
3
2
1
0

-3

-2

-1

0

X-axis

1

2

3

Figure 20: Showing transfer characteristics of circuit 5
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DOUBLE ENDED CLIPPER TO GENERATE A SQUARE WAVE (FIGURE
(6))
1
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5

y axis

0
-6

-4

-2

-0
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5
-2
-2
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7
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8 and on the
negative it started when it was above -2
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5
4
3
2
1

Y-axis


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3 and on the negative part clipping started below -1
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-10

0
-5

-1

0

5

-2
-3
-4
-5
-6

X-axis

Figure 22: Showing transfer characteristics of circuit 7

10

From the experiment conducted above the level of clipping was not exactly as indicated in the
lab manual rather it was less than the original value by (0
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Not only that, but reading the values from the oscilloscope was very hard just
because the values that were being dealt with were very small when noticing the voltage where
clipping started on the oscilloscope
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Despite all the short falls encounter in the experiment, clipping circuits are used for
protection of electronic sensitive devices by limiting voltage and communication
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P
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J
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Electronic Principles (8 ed
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Mlatho, J
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(2018)
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Zomba: Chancellor College
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electronics-tutorials
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