ell project

1. ELL PROJECT
Utkarsh Kumar 2021TT11167
0.

2. TABLE OF CONTENTS
1.Objectives
2.Apparatus used
3.Theory
4.Circuit diagram and explanation
5.Conclusion
1.
Vedio demonstration persent in slide no. 13 and 15*
*according to powerpoint slide numbering system.

3. OBJECTIVE
2.Diode as a full wave rectifier
1.Diode as a half wave rectifier
2.

4. APPARATUS USED
1. Connecting wires
2. Diodes
3. Transformers
4. Capacitor
5. Load(12 v bulb)
6. A power supply
3.

5. THEORY
• Diode is a nonlinear device: Mostly use in converting A.C to D.C current.
© Acts as small resistance in forward direction
∞ Large resistance in reverse direction
• Vanode > Vcathode : Forward biased
• Vanode < Vcathode : Reverse biased
4.

6. THEORY
• Diode Rectification:
The main use of Diode is in rectification circuits. These circuits are
used in converting AC signal into DC signal because of biased
property of diode.
• Two types of Diode rectification:
1. Diode as Half wave rectifier
2. Diode as full wave rectifier
5.

7. THEORY
• Diode as a Half wave rectifier :
• In a half-wave rectifier, only one half of each A.C input cycle
is rectified.
• In one half Diode behave as forward bias and offered
negligiable resistance but in other half Diode start acting as
reverse bias and offered very large resistance and due to this
in that current pass is very negligiable.
6.

8. THEORY
• Diode as a Full wave rectifier :
• In a Full-wave rectifier, both halves of each input cycle of A.C
is rectified.
• Diodes are arranged in circuits in such way that they one sets
behave as forward biased when A.C cycle is in positive
direction and in negative cycle of A.C other sets of Diode
behave as forward biased and in that way both the halves of
each input cycle is converted into pulsating D.C waves.
7.

9. THEORY
• Role of Filters (Capacitors) in Rectifiers :
• Capacitor is used in rectifier circuits to get constant DC
signal(ideally) but in practical less fluctuating DC rather than
pulsating DC. Capacitos acts as source when Diode are
offering high resistance or when the Vout from the main
source is less than than capacitors voltage
8.

10. THEORY
• Role of Tranformers:
• Transforms are used to get step down or step up the voltage. Here, I used it
for step down the voltage.
9.

11. HALF –WAVE RECTIFIER
• In study about the half- wave rectifier, we will see the how with the help of Diode we
can convert A.C wave into pulsating D.C waves.
• In half wave rectification, either the positive or negative half of the AC wave is
passed, while the other half is blocked. Because only one half of the input waveform
reaches the output, it is only 50% efficient if used for power transfer.
• The diode when forward biased will allow current to flow, i.e., in the positive half
cycle of the ac source, it will behave normally like a short or a small resistance. But
when reverse biased, the diode will not allow any flow of current, posing as an almost
infinitely large resistance.
10.

12. HALF –WAVE RECTIFIER
11.

13. FULL –WAVE RECTIFIER
• My second objectives is study about full-wave rectifier – With the help of Diode system we convert the full A.C signal into a
D.C pulsating wave.
• The full wave rectifier circuit consists of two diodes connected to a single load resistance (bulb) with each diode taking it in turn
to supply current to the load
• We apply an AC voltage to the input transformer. During the positive half-cycle of the AC voltage, terminal 1 will be positive,
centre-tap will be at zero potential, and terminal 2 will be negative potential.
• This will lead to forwarding bias in diode D1 and cause current to flow through it. During this time, diode D2 is in reverse bias
and will block current through it.
• During the negative half-cycle of the input AC voltage, terminal 2 will become positive relative to terminal 2 and centre-tap.
This will lead to forwarding bias in diode D2 and cause current to flow through it. During this time, diode D1 is in reverse bias
and will block current through it.
• During the positive cycle, diode D1 conducts, and during the negative cycle, diode D2 conducts and during the positive cycle.
• As a result, both half-cycles are allowed to pass through. The average output DC voltage here is almost twice the DC output
voltage of a half –wave rectifier
12.

14. FULL–WAVE RECTIFIER Ripple Factor**
13.

15. CONCLUSION
• In, the experiment, we see Diode as a full wave rectifier and half wave rectifier and how Diode
instrument is used in converting A.C signals into D.C waves. Bcoz of basic property of Diode is
that it can establish the path for the flow of current in one direction that is possible during
forwarding bias and by good arrangement of electrical instrument in circuits we convert A.C to
D.C waves.
• Full-wave rectifier is more often used bcoz of its high efficiency and low ripple factor than half-
wave rectifier
• In half-wave rectifier only half of A.C signal is rectified while in full-wave rectifier full A.C signal
is rectified. Advantages of half- wave rectifier that it requires lower no. of Diode and this is a
simple circuit but full- wave rectifier is complex system it requires 2 or 4 diodes or may more.
• Thus we see the pros and cons of full and half – wave rectifier and role of capacitor in rectified
circuits(converting pulsating d.c waves into constant waves(ideally)).
14.

16. END
DIODE AS A RECTIFIER
Thank You
.
15