Amrita School of Engineering, Coimbatore
AY 2024-25 EVEN
23ECE185 Electronic Devices and Circuits Laboratory
Expt – 4
Rectifiers - 2
Objective:
This week, you will set up full-wave rectifier circuits and study its operation.
Instructions:
1.
Take care to connect up the circuit exactly as shown, paying particular attention to the grounded
terminals.
2.
Please power up your circuit only after it has been verified by the Lab Staff / Faculty-in-Charge.
3.
The component marked X in the circuits is a 230 / 6-0-6 V center-tapped transformer, fixed on a metal
chassis, with the input and output terminals clearly marked. Take care while handling it – else you might
end up getting a nasty shock.
4.
All the diodes are 1N4007. Please review the characteristics of the diode (those of you who have
characterized a different diode, please get the characteristics of the 1N4007 from your friends who have)
as well as the performance of the Half Wave Rectifier that you have set up, before coming to the lab.
Before coming to the lab, answer the following questions:
1.
If the input to the primary of the transformer is 230 V / 50 Hz, plot (on the same axis), the waveforms
of the signal obtained at A and C.
2.
If RL = 100 Ω, plot the voltage waveform across RL (assume both the diodes are identical).
3.
If the diodes have the characteristic of the 1N4007, plot the voltage waveform across RL. Calculate its
average value.
Procedure:
1.
Connect up the circuit as shown in Fig, 1. Let RL be 100 Ω. Measure and plot the voltage across AB as
the input and the voltage across RL as the output, respectively. Mark all salient points.
2.
Change RL to 560 kΩ. Repeat step 1.
3.
Add a resistor R to the circuit as shown in Fig. 1b. Let R = RL = 100 Ω. Measure and plot the voltage
across AB as the input and the voltage across RL as the output, respectively. Mark all salient points.
4.
Remove the transformer and give a sinusoidal waveform directly and observe and plot the output.
5.
Remove the ground connection at P and connect the load across PQ to obtain a floating load. Now
observe and plot the output.
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Amrita School of Engineering, Coimbatore
AY 2024-25 EVEN
Post-lab questions:
1.
Plot the Voltage Transfer Characteristic of the circuit of Fig. 1b. How is it different from that of Fig. 1a
and why?
2.
For the bridge rectifier shown in Fig. 2, plot the voltage waveforms across the load.
3.
What difference do you notice in the peak values of the output of the fullwave and bridge rectifiers?
4.
Calculate the average value of the output waveforms of the circuits of Fig. 1a and Fig. 2, when the
amplitude of the input waveform is 3 V.
5.
Did you observe a full wave rectified signal in step 4 of the experiment? Justify your observations in the
lab.
Fig. 2
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