Ministry Of Higher Education and Scientific Research

Southern Technical University

Basra Engineering Technical Collage

Electrical Engineering Techniques Department

ELECTRONICS LAB.
Second Year

Done By:
Ibrahim Emad Ibrahim Tabarek Abdulhassan
Zainab Ali Hameed
 SAFETY INSTRUCTIONS

1. Wear appropriate protective lab coats.

2. Keep the workspace tidy: Maintain a clean and organized work

area to prevent accidents and tripping hazards.

3. Use proper tools and equipment: Handle electronic tools and

instruments with care, and ensure they are in good working
condition before use.

4. Power off equipment when not in use: Turn off all electronic
devices and unplug them when not actively working with them.

5. Avoid food and drinks in the lab.

6. Be cautious with electricity: Avoid contact with live circuits, and

use insulated tools to minimize the risk of electric shock.

7. Read and follow instructions carefully: Always refer to equipment

manuals and experiment protocols before starting any task.

8. Never work alone: When handling potentially hazardous materials

or experiments, have a colleague or supervisor nearby for
assistance and in case of emergencies.

9. No unauthorized experiments: Perform only approved experiments

and refrain from any unauthorized activities that could pose risks.

10.Remember, safety is a shared responsibility, and following these

instructions will help ensure a safe and productive environment in
the electronic laboratory.

I
 CONTENT LIST

EXP NO. EXP NAME EXP PAGE

1 Diode Characteristics 1

2 Single phase Half-wave uncontrolled Rectifier 5

Single phase Half wave uncontrolled Rectifier with
3 9
filter
Single phase full-wave uncontrolled rectifier (Bridge
4 13
& center tap).
Single phase full-wave uncontrolled rectifier (Bridge
5 18
& center tap) with filter
6 Clipper (limiter) Circuit. 22

7 Double Diode Positive and Negative Clipping Circuit 26

8 Clamper circuit (DC resistance) 29

Voltage Multiplier Circuit (Doubler, Tripler,
9 32
Quadrupler).
10 Zener Diode Characteristics 36

II
 LAB. APARATUES

INSTRUMENTS:

Oscilloscope DC Power Supply Digital Multimeter Function Generator

Breadboard Wires Probe Cables Center Tap Transformer

Multimeter Multimeter

ELECTRONIC COMPONENTS:

Fixed Resistors Potentiometer

Capacitor

Diode Zener Diode

Transistor
III
 FIRST
SEMESTER
EXPERMENTS

IV
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

EXP NO.: 1
EXP NAME: Diode Characteristics
OBJECTIVE: To study and understand the characteristics of a diode.

THEORY:
Diodes are semiconductor devices that allow current to flow in one
direction only, and their behavior is crucial in various electronic circuits.
Through this experiment, we will explore the voltage-current (V-I)
characteristics of a diode and analyze its behavior in forward and reverse
bias conditions.

Forward Bias: When a positive voltage is applied to the anode and a

negative voltage to the cathode, current flows easily through the diode,
and it is said to be forward biased. In this mode, the diode exhibits low
resistance and allows current to pass through it.

Reverse Bias: When a positive voltage is applied to the cathode and a

negative voltage to the anode, the diode is reverse biased. In this mode,
the diode exhibits high resistance, preventing significant current flow.

FORMULA:
The Average Forward Resistance (𝑹𝒇 ) :

∆𝑉𝑓
𝑅𝑓 =
∆𝐼𝑓

Keep in mind that the forward resistance of a diode is not a constant

value but various with the forward current passing through it. Is also
important to know that the diode must be in the forward biased mood.

1
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

CIRCUIT DIAGRAM:
Diode

V R
DC source

Figure (1.1) Forward Circuit

D1

V
R
DC source

Figure (1.2) Reverse Circuit

WAVEFORMS:

Figure (1.3)
2
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

APPARATUS:
1. Diode (1N4007).

2. Resistor (100 Ω).

3. DC Power Supply (0-5V).

4. Digital Multimeter.

5. Breadboard.

6. Connecting wires.

PROCEDURE:
1. Set up the circuit as per the circuit diagram in figure (1.1) on the
breadboard.

2. Make sure the connections are correct to prevent short circuits.

3. Ensure the power supply is off initially.

4. Increase the forward voltage gradually from 0 V a shown in table

(1.1).

5. Record 𝑰𝒅 and 𝑽𝒅 for each 𝑽𝒔 value.

6. Set up the circuit as per the circuit diagram in figure (1.2) on the
breadboard.

7. Repeat the steps 2 to 5, use table (1.2).

8. Plot on graphical paper the V-I characteristics using the practical

results in tables (1.1) and (1.2):

3
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

𝑽𝒔 (𝒗) 𝑽𝑭 (𝒗) 𝑰𝑭 (𝑨)

0
0.2
0.4
0.5
0.6
0.7
1--------5
Table (1.1)

𝑽𝒔 (𝒗) 𝑽𝑹 (𝒗) 𝑰𝑹 (𝑨)

0
2
4
6
8
10

Table (1.2)

9. Then graphically determine the diode barrier potential 𝑽𝒃 and

forward resistance 𝑅𝑓 .
10.Calculate the forward resistance 𝑅𝑓 .

REPORT:
1. Compere the V-I characteristics of an ideal, practical and complete
diode?
2. How do these differences impact circuit design and analysis?
3. What is the typical Vbias of diode:
a. Silicon.
b. Germanium.

4
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

EXP NO.: 2
EXP NAME: Single phase Half-wave uncontrolled Rectifier.
OBJECTIVE: To understand the working principle of a half-wave
rectifier and to analyze its output characteristics.

THEORY:
A rectifier is an electronic circuit that converts alternating current
(AC) into direct current (DC). In this experiment, we will focus on the
half-wave rectifier, which allows only one-half of the input AC cycle
to pass through and blocks the other half. The circuit consists of a
diode, which acts as a one-way valve for current flow.

During the positive half-cycle of the input AC voltage, the diode

conducts and allows current to flow through the load resistor. As a
result, a positive half-wave rectified output is obtained across the load.
During the negative half-cycle of the input AC voltage, the diode
becomes reverse-biased, blocking the current flow through the load.

The average DC output voltage and rectification efficiency can be

calculated based on the input and output waveforms.

FORMULA:
The rectification efficiency of a half wave uncontrolled rectifier refers
to the ratio of DC power delivered to the load resistance (𝑃𝑑𝑐 ) to the
AC power available at the input (𝑃𝑎𝑐 ). It measures how effectively the
half wave rectifier converts the AC input signal into a DC output
signal.

5
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

The rectification efficiency (η) can be calculated using the formula:

𝑃𝑑𝑐
η= ∗ 100%
𝑃𝑎𝑐

Where,
𝑉𝑜 2
𝑃𝑑𝑐 = ( 𝑉𝑜 is the av output voltage)
𝑅𝐿

𝑉𝑆𝑒𝑐𝑜𝑛𝑑𝑎𝑟𝑦 2
𝑃𝑎𝑐 = ( 𝑉𝑆𝑒𝑐𝑜𝑛𝑑𝑎𝑟𝑦 is the rms input voltage)
2𝑅𝐿

The average DC output voltage (𝑉𝑎𝑣𝑔 ) can be calculated using the

formula:
𝑉𝑝
𝑉𝑎𝑣𝑔 =
𝜋
𝑉𝑝
Note: 𝑉𝑟𝑚𝑠 =
√2

Peak Inverse Voltage (PIV): The PIV occurs at the peak of each half
cycle of the input voltage when the diode is reversed bias.

𝑃𝐼𝑉 = 𝑉𝑝(𝑠𝑒𝑐𝑜𝑛𝑑𝑎𝑟𝑦)

CIRCUIT DIAGRAM:
Diode

+12

ACvoltage 0
source 220v R
-12
V
220V:24V

Figure (2.1)

6
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

WAVEFORMS:

Figure (1.1)

Figure (2.2)

APPARATUS:
1. Diode (1N4007).

2. Resistor (1k Ω).

3. AC Power Supply (220 v).

4. Transformer (220:24 v).

5. Breadboard.

6. Connecting wires.

7. Oscilloscope.

PROCEDURE:
1. Set up the circuit as shown in the circuit diagram in figure (2.1).

2. Ensure that the connections are secure and the diode is oriented
correctly.

3. Use an oscilloscope to visualize the input and output.

4. Record the input and the output voltage values from the oscilloscope.

5. Draw the observed input and output voltages waveforms.

6. Measure the average DC output voltage.

7
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

7. Calculate the average DC output voltage.

8. Calculate the rectification efficiency (η).

9. Measure the peak inverse voltage (PIV).

10.Calculate the peak inverse voltage (PIV).

𝑉𝑝(𝑠𝑒𝑐𝑜𝑛𝑑𝑎𝑟𝑦) 𝑉𝑝(𝑜𝑢𝑡) (𝑣) 𝑉𝑎𝑣 (𝑣) η(%) 𝑃𝐼𝑉(𝑣)

Table (2.1)
REPORT:
1. What is the purpose of load resistor in a half wave uncontrolled
rectifier circuit?
2. How does the load resistor affect the output waveform?

8
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

EXP NO.: 3
EXP NAME: Single phase Half wave uncontrolled Rectifier with
filter.

OBJECTIVE: To understand the working principle of a half-wave

rectifier and its output improvement using a filter circuit.

THEORY:

A half-wave rectifier is a simple electronic circuit that converts an

alternating current (AC) input into a pulsating direct current (DC) output,
allowing only one-half of the AC input waveform to pass through. The
primary component of the half-wave rectifier is a diode, which conducts
current in one direction (forward-biased) and blocks current in the
opposite direction (reverse-biased).

To smoothen the output a capacitor is often added across the load. The
capacitor quickly charges at the beginning of a cycle (positive half-cycle)
and slowly discharges through RL after the positive peak of the input
voltage (when the diode is reverse-biased in the negative half-cycle).

The variation in the capacitor voltage due to the charging and discharging
is called the ripple voltage. Generally, ripple is undesirable; thus, the
smaller the ripple, the better the filtering action,

FORMULA:
1
𝑇 = 𝑇𝑐ℎ𝑎𝑟𝑔𝑒 + 𝑇𝑑𝑖𝑠𝑐ℎ𝑎𝑟𝑔𝑒 =
𝑓

𝑇 is the one cycle period.

𝑇𝑐ℎ𝑎𝑟𝑔𝑒 is the charging time of the capacitor.

𝑇𝑑𝑖𝑠𝑐ℎ𝑎𝑟𝑔𝑒 is the discharging time of the capacitor.

9
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

Ripple Factor (r) is an indication of the effectiveness of the filter and is

defined as:
𝑉𝑟 (𝑝.𝑝)
𝑟=
𝑉𝑑𝑐

1 1
𝑉𝑟 (𝑝.𝑝) ≅ ( ) ∗ 𝑉𝑝(𝑜𝑢𝑡) , 𝑉𝑑𝑐 ≅ (1 − ) ∗ 𝑉𝑝(𝑜𝑢𝑡)
𝑓𝑅𝐿 𝐶 2𝑓𝑅𝐿 𝐶

Where,

𝑉𝑟 (𝑝.𝑝) is the peak-to-peak ripple voltage.

𝑉𝑑𝑐 is the dc (average) value of the filter’s output voltage.

𝑽𝒓(𝒑.𝒑)
𝑽𝒑 𝑽𝒅𝒄

Figure (3.1)

NOTE: The lower the ripple factor, the better the filter. The ripple factor
can be lowered by increasing the value of the filter capacitor or increasing
the load resistance.

CIRCUIT DIAGRAM:
Diode

+12
+
ACvoltage 0
source 220v C R
-
-12
V
220V:24V

Figure (3.2)
10
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

WAVEFORM:

Figure (3.3)

APPARATUS:
1. Diode (1N4007).

2. Resistor (1k Ω).

3. Capacitors (10, 20, 67 µf).

4. AC Power Supply (220 v).

5. Transformer (220:24 v).

6. Breadboard.

7. Connecting wires.

8. Oscilloscope.

PROCEDURE:
1. Set up the circuit as shown in the circuit diagram in figure (3.1).

2. Ensure that the connections are secure and the diode is oriented
correctly.

3. Change the capacitor value as shown in table (3.1).

4. Use an oscilloscope to visualize the input and output.

5. Record the input and the output voltage values from the oscilloscope.

6. Measure peak-to-peak ripple voltage 𝑉𝑟 (𝑝.𝑝) .

11
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

7. Draw the observed input and output voltages waveform.

8. Measure the average DC output voltage

9. Calculate the average DC output voltage.

10.Calculate the Ripple Factor (r).

𝐶(µ𝐹) 𝑉𝑝 (𝑣) 𝑇𝑐ℎ𝑎𝑟𝑔𝑒 (𝑠𝑒𝑐) 𝑇𝑑𝑖𝑠𝑐ℎ𝑎𝑟𝑔𝑒 (𝑠𝑒𝑐) 𝑇(𝑠𝑒𝑐) 𝑉𝑎𝑣 (𝑣) 𝑉𝑟 (𝑝.𝑝) (𝑣) 𝑟
10
20
67

Table (3.1)

Report:
1. How does the value of the filter capacitor affect the output voltage
ripple and the performance of the circuit?

12
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

EXP NO.: 4
EXP NAME: Single phase full-wave uncontrolled rectifier (Bridge &
center tap).

OBJECTIVE: To understand the working principle of a full-wave

rectifier and to analyze its output characteristics.

THEORY:
A full-wave rectifier is an electronic circuit that converts the entire cycle
of an AC input waveform into a unidirectional pulsating DC output
waveform.

The full-wave rectifier can be implemented using a bridge rectifier

configuration, which consists of four diodes arranged in a bridge
arrangement figure (4.1). During the positive half-cycle of the input AC
voltage or two diodes conduct and allow current flow through the load
resistor in one direction. During the negative half-cycle, the other two
diodes conduct and the current flow is reversed, maintaining a
unidirectional flow through the load resistor. Also, full-wave rectifier can
be implemented using a center-tapped transformer, which consists of two
diodes, and a load resistor figure (4.2).

The center-tapped transformer provides a split secondary winding, which

allows the rectification of both positive and negative half-cycles of the
input AC waveform. During the positive half-cycle of the input AC
voltage, the upper diode conducts, allowing current to flow through the
load resistor in one direction. Simultaneously, the lower diode remains
reverse-biased and blocks the current flow. During the negative half-
cycle, the lower diode conducts, and the upper diode blocks the current
flow. This process results in a pulsating DC output waveform.

13
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

FORMULA:
The rectification efficiency of a full wave uncontrolled rectifier refers
to the ratio of DC power delivered to the load resistance (𝑃𝑑𝑐 ) to the
AC power available at the input (𝑃𝑎𝑐 ). It measures how effectively the
full wave rectifier converts the AC input signal into a DC output
signal.

The rectification efficiency (η) can be calculated through:

2
𝑃𝑑𝑐 𝑉𝑑𝑐 /𝑅
For Bridge rectifier: 𝜂= ∗ 100% = 2 /𝑅 ∗ 100%
𝑃𝑎𝑐 𝑉𝑎𝑐

2
𝑃𝑑𝑐 𝑉𝑑𝑐 /𝑅
For center-tap rectifier: 𝜂= ∗ 100% = 2 /2𝑅 ∗ 100%
𝑃𝑎𝑐 𝑉𝑎𝑐

Where,
2𝑉𝑝(𝑜𝑢𝑡)
𝑉𝑑𝑐 =
𝜋
𝑉𝑝(𝑖𝑛)
𝑉𝑎𝑐 = 𝑉𝑟𝑚𝑠 =
√2
Peak Inverse Voltage (PIV):

At using bridge rectifier let's assume that 𝐷1 , 𝐷2 are forward-biased and

examine the reverse across 𝐷3 , 𝐷4 .If the diode (𝐷1 , 𝐷2 ) drops of the
forward-biased. which use center tapped transformer each diode in the
full wave rectifier is alternately forward-biased and then reverse-biased
Where 𝐷2 is assumed to be reverse-biased and 𝐷1 is assumed to be
forward-biased to illustrate the concept

the peak Inverse voltage (PIV) across each reverse-biased diode in terms
of 𝑉𝑝(𝑜𝑢𝑡) 𝑖𝑠:

𝑃𝐼𝑉 = 𝑉𝑝(𝑜𝑢𝑡) + 0.7 𝑉 𝑎𝑡 𝑢𝑠𝑖𝑛𝑔 𝑏𝑟𝑖𝑑𝑔𝑒 𝑟𝑒𝑐𝑡𝑖𝑓𝑖𝑒𝑟

𝑃𝐼𝑉 = 2𝑉𝑝(𝑜𝑢𝑡) + 0.7𝑉 𝑎𝑡 𝑢𝑠𝑖𝑛𝑔 𝑐𝑒𝑛𝑡𝑒𝑟 𝑡𝑎𝑝𝑝𝑒𝑑 𝑡𝑟𝑎𝑛𝑠𝑓𝑜𝑟𝑚𝑒𝑟

14
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

CIRCUIT DIAGRAM:

+12

D3 D1
ACvoltage 0
source 220v

-12
D2 D4 R
V
220V:24V

Figure 4.1)

D1

+12

ACvoltage 0
source 220v D2
R

-12
V
220V:24V

Figure (4.2)

WAVEFORMS:

Figure (4.3)

15
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

APPARATUS:
1. 1N4007_Diode.

2. Resistor (1k Ω).

3. AC Power Supply (220 v).

4. Transformer (220:24 v).

5. Breadboard.

6. Connecting wires.

7. Oscilloscope.

PROCEDURE:
1. Set up the circuit as shown in the circuit diagram in figure (4.1) &
(4.2).
2. Ensure that the connections are secure and the diodes are oriented
correctly.
3. Use an oscilloscope to visualize the input and output waveforms.
4. Record the input and the output voltage values from the oscilloscope.
5. Draw the observed input and output voltages waveforms.
6. Measure the average DC output voltage (𝑉𝑑𝑐 ).
7. Calculate the average DC output voltage (𝑉𝑑𝑐 ).
8. Calculate the rectification efficiency (η).
9. Measure Peak Inverse Voltage (PIV)
10.Calculate Peak Inverse Voltage (PIV)

𝑉𝑖𝑛 (𝑣) 𝑉𝑜𝑢𝑡 (𝑣) 𝑉𝑑𝑐 (v) η (%) PIV(v)

Table (4.1)
16
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

REPORT:
1. How does a full-wave uncontrolled rectifier differ from a half-
wave rectifier in terms of efficiency and output voltage?

2. What's the relationship between the output and input frequency?

why?

17
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

EXP NO.: 5
EXP NAME: Single phase full-wave uncontrolled rectifier (Bridge &
center tap) with filter.

OBJECTIVE: To understand the working principle of a full-wave

rectifier and its output improvement using a filter circuit.

THEORY:
A full wave rectifier is a circuit that converts an alternating current (AC)
input signal into direct current (DC) output signal. The diodes in the
bridge rectifier allow the positive half-cycle voltage to pass through,
while blocking the negative half-cycle voltage. As a result, the output of
the bridge rectifier is a pulsating DC waveform, where the negative half-
cycles are inverted to positive half-cycles.

Which use center-tapped transformer provides two equal and opposite

voltages at its secondary winding. The positive half-cycle voltage is
applied to one of the diodes in the bridge rectifier, while the negative
half-cycle voltage is applied to the other diode. To obtain a smoother DC
output, a filter circuit is employed. The filter circuit typically consists of a
capacitor connected in parallel with the load resistor. The capacitor
charges during the positive half-cycle of the rectified waveform and
discharges during the negative half-cycle.

Filtered F.W.R voltage is better than H.W.R. due to smaller ripple and
capacitor discharges less during the shorter interval between full-wave
pulses, small ripple means more effective filtering.

18
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

FORMULA:
1
𝑇 = 𝑇𝑐ℎ𝑎𝑟𝑔𝑒 + 𝑇𝑑𝑖𝑠𝑐ℎ𝑎𝑟𝑔𝑒 =
𝑓

𝑇 𝑖𝑠 𝑡ℎ𝑒 𝑜𝑛𝑒 𝑐𝑦𝑐𝑙𝑒 𝑝𝑒𝑟𝑖𝑜𝑑.

𝑇𝑐ℎ𝑎𝑟𝑔𝑒 𝑖𝑠 𝑡ℎ𝑒 𝑐ℎ𝑎𝑟𝑔𝑖𝑛𝑔 𝑡𝑖𝑚𝑒 𝑜𝑓 𝑡ℎ𝑒 𝑐𝑎𝑝𝑎𝑐𝑖𝑡𝑜𝑟.

𝑇𝑑𝑖𝑠𝑐ℎ𝑎𝑟𝑔𝑒 𝑖𝑠 𝑡ℎ𝑒 𝑑𝑖𝑠𝑐ℎ𝑎𝑟𝑔𝑖𝑛𝑔 𝑡𝑖𝑚𝑒 𝑜𝑓 𝑡ℎ𝑒 𝑐𝑎𝑝𝑎𝑐𝑖𝑡𝑜𝑟.

Ripple Factor (𝑟)is an indication of the effectiveness of the filter.

𝑉𝑟(𝑝𝑝)
𝑟=
𝑉𝐷𝐶

Where:
1
𝑉𝑟(𝑝𝑝) ≅ ( )𝑉
𝑓𝑅𝐿 𝐶 𝑝
1
𝑉𝐷𝐶 ≅ (1 − )𝑉
2𝑓𝑅𝐿 𝐶 𝑝

Note:

𝒇𝒐𝒖𝒕 = 𝟐 𝒇𝒊𝒏 , 𝑤ℎ𝑒𝑟𝑒 𝒇𝒐𝒖𝒕 𝑖𝑠 𝑡ℎ𝑒 𝑜𝑛𝑒 𝑤𝑒 𝑢𝑠𝑒 𝑖𝑛 𝑡ℎ𝑒 𝑐𝑎𝑙𝑐𝑢𝑙𝑎𝑡𝑖𝑜𝑛𝑠.

CIRCUIT DIAGRAM:

+12

D3 D1
ACvoltage 0
source 220v

-12 +
D2 D4 C R
V
-
220V:24V

Figure (5.1)

19
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

D1

+12
+
ACvoltage 0
source 220v D2
C R
-
-12
V
220V:24V

Figure (5.2)

WAVEFORMS:

Figure (5.3)

APPARATUS:
1. Diode (1N4007).

2. Resistor (1k Ω).

3. Capacitor (10µF,20µF).

4. AC Power Supply (220 v).

5. Transformer (220:24 v).

6. Breadboard.

7. Connecting wires.

8. Oscilloscope.

20
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

PROCEDURE:
1. Set up the circuit as shown in the circuit diagram in figure (5.1 &
5.2).

2. Ensure that the connections are secure and the diode is oriented
correctly.

3. Change the capacitor value as shown in table (3.1).

4. Use an oscilloscope to visualize the input and output.

5. Record the input and the output voltage values from the oscilloscope.

6. Measure peak-to-peak ripple voltage 𝑉𝑟 (𝑝.𝑝) .

7. Draw the observed input and output voltages waveform.

8. Measure the average DC output voltage

9. Calculate the average DC output voltage.

10.Calculate the Ripple Factor (r).

𝐶(µ𝐹) 𝑉𝑝 (𝑣) 𝑇𝑐ℎ𝑎𝑟𝑔𝑒 (𝑠𝑒𝑐) 𝑇𝑑𝑖𝑠𝑐ℎ𝑎𝑟𝑔𝑒 (𝑠𝑒𝑐) 𝑇(𝑠𝑒𝑐) 𝑉𝑎𝑣 (𝑣) 𝑉𝑟 (𝑝.𝑝) (𝑣) 𝑟
10
20
Table (5.1)

REPORT:
1. How does the value of the filter capacitor affect the output voltage
ripple and the performance of the circuit?

21
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

EXP NO: 6
EXP NAME: Clipper (limiter) Circuit.
OBJECTIVE: To design and construct a Diode Limiter circuit and
investigate its behavior in limiting the amplitude of an input signal.

THEORY:
Diode Limiter circuit restricts the input signal's amplitude using diodes.

When the input voltage (Vm) exceeds a reference level +V, the diode acts
as a closed switch, limiting the output to +V. As long as the input voltage
remains above +V, the output stays clamped at +V.

For input voltages below +V, the diode opens, and the circuit behaves as
a voltage divider, passing most of the input voltage to the output. For that
RL should be greater than R.

The circuit effectively removes all signals above +V, resulting in a

clipped output waveform.

FORMULAS:
𝑅𝐿
Peak output voltage: 𝑉𝑃(𝑜𝑢𝑡) = ( ) 𝑉𝑖𝑛
𝑅1 +𝑅𝐿

For the Clipped part: 𝑉𝑜 = 𝑉𝐷𝐶 + 𝑉𝐵

22
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

CIRCUIT DIAGRAM:
R1

+12

ACvoltage D1
source 220v 0
R2

Vdc
-12 (𝑉𝐵𝐼𝐴𝑆 )

V
220V:24V
Figure (6.1) Positive Clipper

R1

+12

ACvoltage D1
source 220v 0
R2

Vdc
-12
(𝑉𝐵𝐼𝐴𝑆 )

220V:24V
V
Figure (6.2) Negative Clipper

WAVEFORMS:

Figure (6.3)

23
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

APPARATUS:
1. Diode 1N4007.

2. DC supply.

3. Resistor (1kΩ, 10kΩ).

4. AC power supply.

5. 220V:24V transformer.

6. Oscilloscope.

7. Breadboard.

8. Connecting wires.

PROCEDURE:
1. Connect the circuit as per circuit diagram (Fig 6.1).
2. Connection to AC Power Supply.
3. Change DC supply voltage and see the value of output with
oscilloscope.
4. Draw Input and output voltage wave forms.
5. Turn off AC supply.
6. Connect the circuit as per circuit diagram (Fig 6.2).
7. Repeat the steps (1-5).

24
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

REPORT:
1. What is the relationship between the clipping level and the DC
voltage?
1. If the variable DC source is reversed, how does this affect the
clipping?
2. What will be the output for the circuit (Fig 6.4)? And why?
3. What will be the output for the circuit (Fig 6.5) when 𝑉𝑑𝑐 = 3 𝑣?
And why?

R1

+12

D1
ACvoltage 0
source 220v R2

-12

V
220V:24V
Figure (6.4)

R1

+12

D1
ACvoltage 0
source 220v R2

-12 V

V
220V:24V

Figure (6.5)

25
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

EXP NO: 7
EXP NAME: Double Diode Positive and Negative Clipping Circuit.
OBJECTIVE: Clipping both the positive and negative at two
independent levels.

THEORY:
In this circuit both of positive and negative clipper are connected in
parallel to clip both positive and negative cycle at same time in different
levels.

It consists of two diodes arranged in parallel but in opposite directions,

and it can clip or remove portions of the input waveform above or below
a certain voltage level.

FORMULAS:
Clipped part voltage: 𝑉𝑜 = 𝑉𝐷𝐶 + 𝑉𝐵

CIRCUIT DAIGRAM:

R1

+12

D1 D2
ACvoltage 0
source 220v R2

-12 V1 V2

V
220V:24V

Figure (7.1)

26
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

WAVEFORMS:

Figure (7.2)

APPARATUS:
1. Diode 1N4007.

2. DC supply.

3. Resistor (1kΩ, 10kΩ).

4. AC power supply.

5. 220V:24V transformer.

6. Oscilloscope.

7. Breadboard.

8. Connecting wires.

27
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

PROCEDURE:
1. Connect the circuit as per circuit diagram (Fig 7.1).
2. Connection to AC Power Supply.
3. Change DC supply voltage and see the value of output with
oscilloscope.
4. Draw Input and output voltage wave forms.
5. Turn off AC supply.

REPORT:

1. What will be the output for the circuit (Fig 7.3)? Why?

R1

+12

D1 D2
ACvoltage 0
source 220v R2

-12 6V 3V

V
220V:24V

Figure (7.3)

28
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

EXP NO: 8
EXP NAME: Clamper circuit (DC resistance).
OBJECTIVE: To understand how a Clamper circuit works and
observe the output waveform when clamping an AC signal to a specific
DC level.

THEORY:
The Clamper circuit is a type of diode-based circuit used to add or
remove a DC level to an AC signal. Its "clamps" the AC waveform to a
specific DC level. This experiment aims to explore the Clamper circuit's
behavior using a DC resistance in the circuit.

A Clamper circuit consists of a diode, a capacitor, and a DC resistance

connected in series. The capacitor stores charge when the input voltage is
positive, and when the input voltage becomes negative, the diode
conducts, allowing the stored charge to discharge through the DC
resistance. This process shifts the output waveform by a certain DC
voltage level.

FORMULAS:
RC Time constant (sec): 𝜏 = 𝑅𝐶
1
Period (sec): T=
𝑓

For good clamping action: 𝜏 ≥ 10𝑇

For excellent clamping action: 𝜏 ≥ 100𝑇

29
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

CIRCUIT DAIGRAM:
-+ c -+

+12

ACvoltage 0 D1 R
source 220v

-12

V
220V:24V
Figure (8.1) Positive Clamper

+ c-

+12

ACvoltage 0 D1 R
source 220v

-12

220V:24V
V
Figure (8.2) Negative Clamper

WAVEFORMS:

Figure (8.3)

30
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

APPARATUS:
1. Diode 1N4007.
2. Capacitor 20 µF.
3. Resistor 12KΩ.
4. AC power supply.
5. 220V:24V transformer.
6. Breadboard.
7. Connecting wires.
8. Oscilloscope.
9. Breadboard.
10.Connecting wires.

PROCEDURE:
1. Connect the clamper circuit as per circuit diagram (Fig 8.1).
2. Connection to AC Power Supply.
3. Measure the value of output with oscilloscope.
4. Draw Input and output voltage wave forms.
5. Repeat steps (1-4) with different resistance values (Ω).
6. Compare the output waveform and DC shift for each resistor
value.

REPORT:
1. Investigate the effect of varying the input frequency, resistance
value and capacitance value on the Clamper circuit's behavior.

2. For 60Hz what values of RC time constant is good for clamping

circuit.
31
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

EXP NO: 9
EXP NAME: Voltage Multiplier Circuit (Doubler, Tripler,
Quadrupler).

OBJECTIVE: To construct a voltage multiplier circuit and understand

its working principles.

The voltage Multiplier circuit is designed to (double, triple, quadrupler)

the input voltage, providing an output voltage that is (twice, three-time,
four time) the amplitude of the input.

THEORY:
A voltage doubler circuit is a rectification circuit that uses diodes and
capacitors to increase the DC voltage level. It operates by utilizing the
charging and discharging characteristics of capacitors. During one half of
the AC input cycle, the capacitor charges to the peak value of the input
voltage. During the other half cycle, the capacitor discharges its stored
charge into a second capacitor in series, effectively doubling the voltage.

FORMULAS:
𝑂𝑢𝑡𝑝𝑢𝑡 𝑉𝑜𝑙𝑡𝑎𝑔𝑒
𝑉𝑜𝑙𝑡𝑎𝑔𝑒 𝑀𝑢𝑙𝑡𝑖𝑝𝑙𝑖𝑐𝑎𝑡𝑖𝑜𝑛 𝑅𝑎𝑡𝑖𝑜 =
𝐼𝑛𝑝𝑢𝑡 𝑆𝑒𝑐𝑜𝑛𝑑𝑎𝑟𝑦 𝑉𝑜𝑙𝑡𝑎𝑔𝑒

32
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

CIRCUIT DAIGRAM:
+ C1 -

+12

ACvoltage 0
source 220v

-12
D1 D2

V
220V:24V + C2 -

-
V

Figure (9.1) Doubler Circuit

-
V

+ C1 - + C3 -

+12

ACvoltage 0
source 220v

-12
D1 D2 D3

V
220V:24V + C2 -

Figure (9.2) Tripler Circuit

+ C1 - + C3 -

+12

ACvoltage 0
source 220v

-12
D1 D2 D3 D4

V
220V:24 + C2 - + C2 -
V

-
V

Figure (9.3) Quadrupler Circuit

33
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

APPARATUS:
1. Diodes 1N4007 (4).
2. Capacitors (4).
3. AC power supply.
4. 220V:24V transformer.
5. Multimeter/Oscilloscope (for voltage measurements).
6. Breadboard.
7. Connecting wires.

PROCEDURE:
1. Connect the doubler circuit as per circuit diagram (Fig 9.1).
2. Connection to AC Power Supply.
3. Measure the value of output.
4. Determine the Multiplication ratio.
5. Connect tippler circuit (Fig 9.2).and repeat step 1 to 4.
6. Connect quadrupler circuit (Fig 9.2).and repeat step 1 to

PRECAUTIONS:
1. Verify all connections are secure and correctly placed on the
breadboard.
2. Double-check the polarity of the capacitors and diodes.

34
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

REPORT:
1. Compare the measured output voltage to the theoretical voltage
doubling ratio. Discuss any discrepancies and potential reasons for
differences.
2. Design and name a circuit that multiply input voltage 5 times.

35
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

EXP NO: 10
EXP NAME: Zener Diode Characteristics.
OBJECTIVE: To investigate the impacts of forward and reverse bias
on Zener diode current and to perform experimental measurements to
construct a Zener voltage regulator.

Determining the range within which the Zener diode effectively maintains
a constant output voltage.

THEORY:
A Zener diode is a special type of semiconductor diode that is designed to
operate in the reverse breakdown region. When a Zener diode is reverse
biased and the applied voltage exceeds its breakdown voltage (also
known as Zener voltage), it starts conducting and maintains a nearly
constant voltage across its terminals.

The Zener diode characteristics can be studied by plotting the voltage

across the diode 𝑉𝑍 () versus the current flowing through it (𝐼𝑍 ) when it is
reverse biased. This V-I characteristic curve shows that, in the reverse
breakdown region, the voltage remains relatively constant over a wide
range of current variations.

FORMULAS:
∆𝑉𝑍
𝑍𝑍 =
∆𝐼𝑍

CIRCUIT DAIGRAM:
36
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

Z1
R
DC source

Figure (10.1) Forward Circuit

Z1

V
R
DC source

Figure (10.2) Reverse Circuit

WAVEFORM:

Figure (10.3) V-I Characteristics

APPARATUS:
37
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

1. Zener Diode.
2. DC supply.
3. Resistor 1kΩ.
4. Ammeter, voltmeter.
5. Breadboard.
6. Connecting wires.

PROCEDURE:
1. Connect the forward circuit as per circuit diagram (Fig 10.1).
2. Vary the DC Power Supply from (0 to 2V).
3. Record If and Vf for each step (Table 10.1).
4. Connect the Reverse circuit as per circuit diagram (Fig 10.2).
5. Vary the DC Power Supply from (0 to -6.5V).
6. Record IR and VR for each step (Table 10.2).
7. Calculate Zz. and record it in (Table 10.2).
8. Draw the curve (I against V) for both forward and reverse biased.
9. Determine the reverse and forward breakdown voltage on the
curve.

38
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

VSource Vf (v) If (A)

0
0.5
0.7
0.8
0.9
1
1.1
1.2
1.5
2

Table (10.1)

VSource VR (v) IR (A) ZZ (Ω)

0
-2
-4
-4.4
-4.5
-4.6
-4.7
-4.8
-4.9
-5
-5.2
-5.6
-6
-6.5

Table (10.2)

39
Basra Engineering Technical College B.Sc. Ibrahim Emad
Electrical Power Eng. Tech. Dep. B.Sc. Tabarek Abdulhassan
Electronics LAB. / 2nd Year B.Sc. Zainab Ali Hameed
2024/2025

REPORT:
1. Explain the differences between Zener diodes and regular diodes in
terms of their voltage-current characteristics and applications.
2. How does the breakdown voltage of a Zener diode affect its
operation as a voltage regulator?
3. What are the factors that may cause a Zener diode to overheat or
fail in a voltage regulation circuit? How can these issues be
mitigated to ensure reliable and stable performance?

40
 Student Name:

Class:

. Electrical Power Tech. Eng. Dep. Bench NO.:

Electronics LAB. Date:

EXP NO.:

EXP Name:

Objective:

1) Circuit Diagram:

2) Results:

3) Calculations:

NOTE: Any waveforms should

be attached in a graph-paper.