Full wave rectifier

investigatory projects class 12

1. Aim
To understand the working of full wave rectifier using p-n junction
diodes and to design a circuit diagram of half wave rectifier using step
down transformer (220V AC – 12V AC), diodes, LED and suitable
resistances.

2. Introduction and principle of a rectifier

3. Apparatus used
Step-down transformer (220V AC – 12V AC)
p-n junction diode (IN 4007)
Circuit board
Wires
9V battery and battery connector
LED (5mm, 1.5V)
Resistors
Push button type toggle switch

4. Theory and working
1.) Working of p-n junction diode in forward and reverse biasing

5. 2.) full wave rectifier

6. 3.) Circuit diagram used in making of full wave rectifier and its working

7. When the push button is in ‘released state’ then terminal ‘2’ is
connected to terminal ‘3’, when push button is in ‘active or pressed’
then terminal ‘2’ is connected to terminal ‘1’.
The push button connected to diode 1 is ‘button 1’ and the other one is
‘button 2’.

8. When ‘button 1’ is pressed and ‘button 2’ is released then it is
equivalent to first half wave of AC. In this state, diode 1 is forward
biased, diode 2 is reverse biased and current flows through LED,
through diode 1.
When ‘button 2’ is pressed and ‘button 1’ is released then it is
equivalent to second half wave of AC. In this state, diode 1 is reverse
biased, diode 2 is forward biased and current does flows through LED,
through diode 2.

9. Uses of rectifiers


Write yourself

Conclusion
The output of full wave rectifier clearly shows that potential difference
is stable, which shows that current is flowing in one direction during
positive half and negative half cycles of AC. We are also able to
measure potential difference across LED using DC voltmeter.

Sources of errors

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Precautions
Keep away from high voltage current.

10. Bibliography
NCERT textbook of class 12
Physics by S.L.Arora
Circuits available on internet