DESIGN AND IMPLEMENTATION OF HALF-WAVE RECTIFIER

USING DIODE
Experiment No. 9
Name: Sarim Ahmad
Roll Number: 0732-BS-SP-PHY-22
Lecture Delivered: 3 February, 2023
Performance Date: 3 February, 2023
Submission Date: 5 May, 2023
Submitted to: Mr. Salman Mahmood & Mr. Shehzad Hassan
sarimahmad890@gmail.com
Explanation:
The following is the construction for the half wave
Abstract— Half-wave rectifiers transform AC voltage to DC rectification we use transformer in its step down conditions
voltage. A half-wave rectifier circuit uses only one diode for
which is that no of turns in primary coil is greater than the
the transformation.
number of turns in the secondary coil.
TABLE OF CONTENT Which will give basically two functions there one is that
its not connected mutually prevent from high level short
1. INTRODUCTION........................................................................1 circuit and while we are using the step down transformer it
will give the lover voltage. We connected is as follow.
2. APPARATUS................................................................................1
3. APPARATUS FUNCTION.........................................................1
4. THEORY.......................................................................................1
5. PROCEDURE...............................................................................2
6. DIAGRAM....................................................................................3
7. WAVEFORM SIGNALS............................................................3
8. ADVANTAGES AND DISADVANTAGES..............................3
2. APPARATUS
9. CONCLUSION.............................................................................3  Diode 1N4007
10. REFERENCES........................................................................3  Ground
 Resistance 1kohm
 Connecting wires
 Oscilloscope
1. INTRODUCTION
Rectification is a basic term used majorly in a AC to DC
conversion purpose so today we are describing how the 3. APPARATUS FUNCTION
rectification and a half wave rectification occurs. A diode is a two-terminal electronic component that
Rectification: In dictionary we can say it as “To purify conducts current primarily in one direction (asymmetric
something especially by repeated or fractional conductance) majorly used as rectifiers
distillation.” Resistance will oppose the flow of current in the circuit
Now in electronics we define it as: “A rectification is a Oscilloscope will use to take digital output of the graph .
process in which a device use one or more than one p-n Multisim is work on node analysis so we connect each
junction diode to convert an alternating current into dc element with the ground which primarily used as source.
current , the device is known as rectifier.”
4. THEORY
Half-wave rectification:-
A half-wave rectification is where an alternating voltage of
It’s a rectification in which a rectifier clips one cycle and
period T called input voltage is applied to a diode D which
shows other cycle as an output but in a dc current. In a
is connected in series with a load resistance R.
forward direction it clips negative cycle as like this in a
reverse direction it clips positive cycle.
1
a power transformer with a diode and a resistor connected
forward biased, so it offers a very low resistance and
to the secondary of the transformer. We will use the
piecewise linear approach in analysing this circuit, current flows through R. The flow of current through
assuming the diode forward resistance rf 0 when the R causes a potential drop across it which varies in
diode is “on”. accordance with the alternating input.
The input signal, vI , is, in general, a 220 V (rms), 60 Hz
AC signal. Recall that the secondary voltage, vS, and
primary voltage, vI , of an ideal transformer . Now N1 and
N2 are the number of primary and secondary turns,
respectively.
The ratio N1 N2 is called the transformer turns ratio. The
transformer turns ratio will be designed to provide a - Negative cycle:
particular secondary voltage, Vs, which in turn will During the negative half cycle i.e., during the period T/2 ->
produce a particular output voltage Vo. T the diode is reverse biased. Now it offers a very high
If a capacitor is added in parallel with the load resistor of a resistance, so practically no current flows through R and
half-wave rectifier to form a simple filter circuit, we can potential drop cross it is almost zero. The same events
begin to transform the half-wave sinusoidal output repeat during the next cycle and so on.
into a DC voltage. The voltage across the capacitor follows
the initial portion of the signal voltage (the positive half of
the output sine wave). When the signal voltage reaches its
peak and begins to decrease, the voltage across the
capacitor also starts to decrease, which means the capacitor
starts to discharge. The only discharge current path is
through the resistor. If the RC time constant is large, the Uni direction:
voltage across the capacitor discharges exponentially with
The current through R flows in only one direction which
time. During this time period, the diode is cut off.
means it is a direct current. However, this current flows in
 Diode as ideal:
The diode was considered ideal. When the practical diode pulses. The Voltage Which Appears Across load
model is used with the barrier potential of 0.7 V taken into resistance R is known as output voltage.
account, this is what happens. During the positive half-
cycle, the input voltage must overcome the barrier
potential before the diode becomes forward-biased. This
results in a half-wave output with a peak value that is 0.7
V less than the peak value of the input. The expression for
the peak output voltage is V.
The effect of the barrier potential on the half-wave
rectified output voltage is to reduce the peak value of the
input by about 0.7 V. It is usually acceptable to use the 5. PROCEDURE
ideal diode model, which neglects the effect of the barrier
 Connect all the apparatus on breadboard as shown
potential, when the peak value of the applied voltage is
in the figure.
much greater than the barrier potential (at least 10 V, as a
 Now connect channel A of the oscilloscope with
rule of thumb). However, we will use the practical model
the source AC and ground as this
of a diode, taking the 0.7 V barrier potential into account
 The source is AC so this will show both upper
unless stated otherwise.
and lower cycles means positive and negative
Working: cycle.
Now one half of alternating current cycle is converted  After you allow source to pass the voltage then
into direct current.  You‘ll able to see the oscilloscope as the
sinusoidal graph will appear.
- Positive cycle-
 Now moving towards our implementation of the
During the positive half cycle of the input alternating
half wave rectification we have to connect the
voltage Le during the interval 0- 7/2, the diode D is oscilloscope across the load resistance
2
  Now to see the graph click on the oscilloscope
7. WAVEFORM SIGNALS
which will give the result.

6. DIAGRAM
 Schematic Circuit Diagram:

8. ADVANTAGES AND DISADVANTAGES

Dis-advantages:
• Low output voltage
• Loss of half cycle or power

9. CONCLUSION
We summarized it as the diode is a useful device at a
cheap cost so it will be a benefit for us acknowledge about
it and used it in many usedful ways.

10. REFERENCES
 B.L.Theraja, Basic Electronics Solid State, Fifth.
1980.
 Thomas L. Floyd, Electronic Devices
(conventional current), 9th ed. 2012