University of Tripoli
Faculty of Engineering
Electrical and Electronic Engineering Department
EE311 – Electronic Laboratory
Spring 2023
Report of experiment #2
Bridge Rectifier
Name: Mohamed Mustafa Kamil
ID: 2180205565
Group: D
Bench: 2
Instructor: Eng. Heba M. Zegallai
EE311 LAB
Pg. 01
Introduction:
A bridge rectifier is a type of full wave rectifier that uses four or more diodes in a bridge circuit configuration to
efficiently convert Alternating Current (AC) into Direct Current (DC). The output wave generated is of the same polarity
irrespective of the polarity at the input.
Figure.1 show the basic full-wave bridge rectifier.
Figure .1 - The basic full-wave bridge rectifier
Bridge rectifiers are classified into several types based on factors such as type of supply, controlling capability, and
bridge circuit configurations. They are mainly classified into single-phase and three-phase rectifiers. Both of these types
can be further classified into uncontrolled, half-controlled, and full-controlled rectifiers.
The best type of rectifier for a particular application depends on the specific requirements of the circuit or device where
it will be use.
Applications of a Bridge Rectifier:

Used for the conversion of AC to DC voltages.

To generate polarized voltages, these are implemented in electric welding’s.

Employed in rolling stock, toehold and three-phase motors for the operation of trains.

Mostly bridge rectifiers are applied in modulations, multipliers and demodulation equipment.

Used for signal peak detection services and in AM radios too.
The principle of operation of the bridge rectifier:
When input AC signal is applied across the bridge rectifier, during the positive half cycle diodes D1 and D3 are forward
biased and allows electric current while the diodes D2 and D4 are reverse biased and blocks electric current. On the other
hand, during the negative half cycle diodes D2 and D4 are forward biased and allows electric current while diodes D1 and
D3 are reverse biased and blocks electric current.
During the positive half cycle, the terminal A becomes positive while the terminal B becomes negative. This causes the
diodes D1 and D3 forward biased and at the same time, it causes the diodes D2 and D4 reverse biased.
EE311 LAB
Pg. 02
The current flow direction during the positive half cycle is shown in the Figure .2 (I.e. A to D to C to B).
Figure .2 - Bridge rectifier during positive half cycle
During the negative half cycle, the terminal B becomes positive while the terminal A becomes negative. This causes
the diodes D2 and D4 forward biased and at the same time, it causes the diodes D1 and D3 reverse biased.
The current flow direction during negative half cycle is shown in the Figure .3 (I.e. B to D to C to A).
Figure .3 - Bridge rectifier during negative half cycle
EE311 LAB
Pg. 03
A diode rectifier forms an essential building block of the DC power supplies required to power electronic
equipment. A block diagram of such a power supply is shown in the Figure. 4
Figure .4 - Block diagram of a dc power supply
The DC voltage VO is required to be as constant as possible in spite of variations in the ac line voltage and
in the current drawn by the load.
The output of the rectifier filter, though much more constant than without the filter, still contains a timedependent component, known as ripple. To reduce the ripple and to stabilize the magnitude of the dc output
voltage of the supply against variations caused by changes in load current, a voltage regulator is employed.
Such a regulator can be implemented using the zener shunt regulator
To smooth the output of the rectifier a reservoir capacitor is used - placed across the output of the reciter and
in parallel with the load.
The smoothing works due to the capacitor charges up when the voltage from the rectifier rises above that of
the capacitor and then as the rectifier voltage falls, the capacitor provides the required current from its stored
charge.
This is how the capacitor is able to provide charge when it is not available from the rectifier, and accordingly
the voltage varies considerably less than if the capacitor were not present.
The capacitor smoothing will not provide total voltage stability, As long as there is some variation in the
voltage. In fact the higher the value of the capacitor, the greater the smoothing
Figure .5 - The capacitor smoothing
EE311 LAB
Pg. 04
Objectives of the Experiment:





To assemble the circuit of a bridge rectifier.
To investigate the use of capacitor filter to reduce the ripple.
To determine the relationship between DC output voltage and AC input voltage, when operating the circuit
without smoothing capacitor.
To state the ratio of the smoothed DC output voltage to the AC input voltage, when the circuit is operating off
load (No load connected).
To compare between half-wave and full-wave rectifier circuit
Equipment List:
1.
2.
3.
4.
5.
6.
7.
8.
4-1N4007 Si diodes.
Digital Multimeter.
Resistors: 1 − 390Ω.
Capacitors: 1 − 100μ𝐹 𝑎𝑛𝑑 2 − 220μ𝐹.
Function generator with integral AC/DC power supply.
Dual-trace oscilloscope.
Set of jumpers.
Connection cables.
Procedure and Measurements:
Part 1: Bridge rectifier without capacitor:
1. For full-wave, the circuit is connected as shown in the Figure .6. For half-wave, one of the diodes is removed.
The voltage source was adjusted to (12Vp-p) and the frequency (50Hz).
Figure .6
EE311 LAB
Pg. 05
2. The output frequency and voltage were measured at each of the full wave and halve wave Repeat step 2 but now
reverse the terminals.

For full-wave:
𝑓=
1
1
=
= 111𝐻𝑧
𝑇 9 ∗ 10−3
𝑉𝑜−𝑝𝑝 = 4.73𝑉
Figure .7

For half-wave:
𝑓=
1
1
=
= 52.6𝐻𝑧
𝑇 19 ∗ 10−3
𝑉𝑜−𝑝𝑝 = 4.77𝑉
Figure .8
3. Simulation:
Figure .9

For full-wave:
𝑓=
1
1
=
= 100𝐻𝑧
𝑇 10 ∗ 10−3
𝑉𝑜−𝑝𝑝 = 4.64𝑉
EE311 LAB
Pg. 06
Figure .01

For half-wave:
𝑓=
1
1
=
= 50𝐻𝑧
𝑇 20 ∗ 10−3
𝑉𝑜−𝑝𝑝 = 4.65𝑉
Part 2: Bridge rectifier with smoothing capacitor (𝟏𝟎𝟎𝝁𝑭):
1. For full-wave, the circuit is connected as shown in the Figure .11. For half-wave, one of the diodes is removed.
The voltage source was adjusted to (12Vp-p) and the frequency (50Hz).
Figure .11
2. 𝑉𝑜−𝑎𝑣𝑔(𝐷𝐶) , 𝑉𝑝𝑝 , 𝑉𝑟 (𝑟𝑚𝑠) and %𝑟𝑖𝑝𝑝𝑙𝑒 all measured.
EE311 LAB
Pg. 07

For full-wave:
𝑉𝑝𝑝 = 0.8𝑉
𝑉𝑟 (𝑟𝑚𝑠) =
𝑉𝑝𝑝
2√3
=
0.8𝑉
2√3
= 0.231𝑉
𝑉𝑜−𝑎𝑣𝑔(𝐷𝐶) = 4.5𝑉
%𝑟𝑖𝑝𝑝𝑙𝑒 =
𝑉𝑟 (𝑟𝑚𝑠)
0.231𝑉
∗ 100 =
∗ 100 = 5.13% < 6.5%
𝑉𝑜−𝑎𝑣𝑔(𝐷𝐶)
4.5𝑉
%𝑟𝑖𝑝𝑝𝑙𝑒(𝑐𝑎𝑙𝑐𝑢𝑙𝑎𝑡𝑖𝑜𝑛) =

1
2√3 ∗ 2𝑓𝑠 ∗ 𝑅𝑙 ∗ 𝐶
∗ 100 = 7.4%
For half-wave:
𝑉𝑝𝑝 = 1.6𝑉
𝑉𝑟 (𝑟𝑚𝑠) =
𝑉𝑝𝑝
2√3
=
1.6𝑉
2√3
= 0.462𝑉
𝑉𝑜−𝑎𝑣𝑔(𝐷𝐶) = 3.6𝑉
%𝑟𝑖𝑝𝑝𝑙𝑒 =
𝑉𝑟 (𝑟𝑚𝑠)
0.462𝑉
∗ 100 =
∗ 100 = 12.83% > 6.5%
𝑉𝑜−𝑎𝑣𝑔(𝐷𝐶)
3.6𝑉
%𝑟𝑖𝑝𝑝𝑙𝑒(𝑐𝑎𝑙𝑐𝑢𝑙𝑎𝑡𝑖𝑜𝑛) =
1
2√3 ∗ 𝑓𝑠 ∗ 𝑅𝑙 ∗ 𝐶
= 14.8%
3. Simulation:
Figure .12 – Ripple for full-wave
EE311 LAB
Pg. 08
Figure .13 – Ripple for half-wave

For full-wave:
𝑉𝑝𝑝 = 0.716𝑉
𝑉𝑟 (𝑟𝑚𝑠) =
𝑉𝑝𝑝
2√3
=
0.716𝑉
2√3
= 0.207𝑉
𝑉𝑜−𝑎𝑣𝑔(𝐷𝐶) = 4.23𝑉
%𝑟𝑖𝑝𝑝𝑙𝑒 =

𝑉𝑟 (𝑟𝑚𝑠)
0.207𝑉
∗ 100 =
∗ 100 = 4.9% < 6.5%
𝑉𝑜−𝑎𝑣𝑔(𝐷𝐶)
4.23𝑉
For half-wave:
𝑉𝑝𝑝 = 1.550𝑉
𝑉𝑟 (𝑟𝑚𝑠) =
𝑉𝑝𝑝
2√3
=
1.550𝑉
2√3
= 0.447𝑉
𝑉𝑜−𝑎𝑣𝑔(𝐷𝐶) = 3.8𝑉
%𝑟𝑖𝑝𝑝𝑙𝑒 =
𝑉𝑟 (𝑟𝑚𝑠)
0.447𝑉
∗ 100 =
∗ 100 = 11.76% > 6.5%
𝑉𝑜−𝑎𝑣𝑔(𝐷𝐶)
3.8𝑉
EE311 LAB
Pg. 09
Part 3: Bridge rectifier with smoothing capacitor (𝟒𝟒𝟎𝝁𝑭):
1. For full-wave, the circuit is connected as shown in the Figure .14. For half-wave, one of the diodes is removed.
The voltage source was adjusted to (12Vp-p) and the frequency (50Hz).
Figure .14
2. 𝑉𝑜−𝑎𝑣𝑔(𝐷𝐶) , 𝑉𝑝𝑝 , 𝑉𝑟 (𝑟𝑚𝑠) and %𝑟𝑖𝑝𝑝𝑙𝑒 all measured.

For full-wave:
𝑉𝑝𝑝 = 0.44𝑉
𝑉𝑟 (𝑟𝑚𝑠) =
𝑉𝑝𝑝
2√3
=
0.44𝑉
2√3
= 0.127𝑉
𝑉𝑜−𝑎𝑣𝑔(𝐷𝐶) = 4.22𝑉
%𝑟𝑖𝑝𝑝𝑙𝑒 =
𝑉𝑟 (𝑟𝑚𝑠)
0.127𝑉
∗ 100 =
∗ 100 = 3% < 6.5%
𝑉𝑜−𝑎𝑣𝑔(𝐷𝐶)
4.22𝑉
%𝑟𝑖𝑝𝑝𝑙𝑒(𝑐𝑎𝑙𝑐𝑢𝑙𝑎𝑡𝑖𝑜𝑛) =

1
2√3 ∗ 2𝑓𝑠 ∗ 𝑅𝑙 ∗ 𝐶
∗ 100 = 1.682%
For half-wave:
𝑉𝑝𝑝 = 0.8𝑉
𝑉𝑟 (𝑟𝑚𝑠) =
𝑉𝑝𝑝
2√3
=
0.8𝑉
2√3
= 0.231𝑉
𝑉𝑜−𝑎𝑣𝑔(𝐷𝐶) = 4𝑉
%𝑟𝑖𝑝𝑝𝑙𝑒 =
𝑉𝑟 (𝑟𝑚𝑠)
0.231𝑉
∗ 100 =
∗ 100 = 5.77% < 6.5%
𝑉𝑜−𝑎𝑣𝑔(𝐷𝐶)
4𝑉
%𝑟𝑖𝑝𝑝𝑙𝑒(𝑐𝑎𝑙𝑐𝑢𝑙𝑎𝑡𝑖𝑜𝑛) =
1
2√3 ∗ 𝑓𝑠 ∗ 𝑅𝑙 ∗ 𝐶
= 3.36%
EE311 LAB
Pg. 10
3. Simulation:
Figure .15 – Ripple for full-wave
Figure .16 – Ripple for half-wave

For full-wave:
𝑉𝑝𝑝 = 0.178𝑉
𝑉𝑟 (𝑟𝑚𝑠) =
𝑉𝑝𝑝
2√3
=
0.178𝑉
2√3
= 0.05𝑉
𝑉𝑜−𝑎𝑣𝑔(𝐷𝐶) = 4.22𝑉
%𝑟𝑖𝑝𝑝𝑙𝑒 =
𝑉𝑟 (𝑟𝑚𝑠)
0.05𝑉
∗ 100 =
∗ 100 = 1.18% < 6.5%
𝑉𝑜−𝑎𝑣𝑔(𝐷𝐶)
4.22𝑉
EE311 LAB
Pg. 11

For half-wave:
𝑉𝑝𝑝 = 0.4𝑉
𝑉𝑟 (𝑟𝑚𝑠) =
𝑉𝑝𝑝
2√3
=
0.4𝑉
2√3
= 0.115𝑉
𝑉𝑜−𝑎𝑣𝑔(𝐷𝐶) = 4.28𝑉
%𝑟𝑖𝑝𝑝𝑙𝑒 =
𝑉𝑟 (𝑟𝑚𝑠)
0.115𝑉
∗ 100 =
∗ 100 = 2.7% < 6.5%
𝑉𝑜−𝑎𝑣𝑔(𝐷𝐶)
4.28𝑉
Comments:
It is observed that the ripple decreases with the increase capacitance of the capacitor.
The ripple in a full wave is less than the ripple in a half wave.
Conclusion:

A bridge rectifier is a full-wave rectifier with two diodes that operate during each AC cycle.

A full-wave bridge rectifier's output frequency is double the input frequency.

Ripple frequency refers to the frequency of fluctuations in a rectifier's DC output voltage.

By removing one of the circuit's diodes, a full-wave bridge rectifier can be converted to a half-wave rectifier.

Rectifier is an important device that converts alternating current to direct current by using diodes.

The smoothing capacitor converts the initiator’s full-wave rippled output to a mare smooth DC output voltage.