Aim

To understand the working of half 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.

Introduction and principle of a rectifier

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

Theory and working

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

2.)Half wave rectifier

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

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 is ‘button 1’ and the other one is ‘button 2’.

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

When ‘button 2’ is pressed and ‘button 1’ is released then it is equivalent to second half wave of AC. In this state, diode is reverse biased and current does not flow through LED.

Uses of rectifiers

Write yourself

Conclusion

The output of half wave rectifier clearly shows that potential difference is not stable but it is fluctuating, which shows that current is flowing only during positive half cycle of AC and negative half cycle of AC is rectified.

Sources of errors

Write yourself

Precautions

Keep away from high voltage current.

Bibliography

NCERT textbook of class 12

Physics by S.L.Arora

Circuits available on internet