Information Technology University Department of Electrical Engineering Electronic Devices and Circuits Lab Manual 6
Full Wave Bridge Rectifier Name
Created by: Engr.Yasir Manzoor, Engr. Zafarullah Date: August 21, 2015 Last updated by: Engr.Yasir Manzoor, Engr. Zafarullah Date: August 21, 2015
Reviewed By: Mr. Talha Rehmani
Approved by the HOD: Dr. Tauseef Tauqeer
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Lab 06 Full Wave Bridge Rectifier
Roll No.
Department of Electrical Engineering Electronic Devices and Circuits Faculty Member Name: Sir Talha Rehmani
Session
Signature:________________________ Lab Engineer 1 Name: Engr.Yasir Manzoor
Semester:
Signature:________________________ Lab Engineer 2 Name: Engr.Zafarullah
Date
Signature:________________________
Report Marks: _______ Out of _______ 2|Page
Viva Marks: _______Out of _________
Lab 06 Full Wave Bridge Rectifier
Contents 6
FULL WAVE BRIDGE RECTIFIER ................................................................................................................ 4 6.1 6.2 6.3 6.4 6.5 6.6 6.7
6.8
6.9
INTRODUCTION: .........................................................................................................................................4 OBJECTIVE .................................................................................................................................................4 EQUIPMENT ...............................................................................................................................................4 CONDUCT OF LAB .......................................................................................................................................4 THEORY AND WORKING ...............................................................................................................................4 PERFORMANCE PARAMETERS FOR TWO PULSE RECTIFIER ANALYSIS ......................................................................5 PROCEDURE: ..............................................................................................................................................6 Without Filter ...............................................................................................................................6 With Capacitor Filter ....................................................................................................................9 TROUBLESHOOTING EXERCISE......................................................................................................................10 Diode short circuited ..................................................................................................................10 Diode open circuited ...................................................................................................................11 Full wave bridge rectifier with function generator .....................................................................12 STUDENT LEARNING OUTCOME ...................................................................................................................13
1 2 3 4 5
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Lab 06 Full Wave Bridge Rectifier
6 Full Wave Bridge Rectifier 6.1 Introduction: A rectifier is a circuit widely used in power supplies, converters and other electronic devices where we need to reduce AC voltages to DC values. Full wave rectifier gives two cycle over complete input. Full wave rectifier is better in many aspects then half wave as it have double average power, load handling capacity and less ripple factor.
6.2 Objective 1. 2. 3. 4. 5.
To study basic parameters of full wave rectifier and their importance. To implement full wave rectifier and study the input and output wave difference. To observe effect of capacitor filter in full wave rectifier. To calculate ripple factor graphically using oscilloscope. To troubleshoot the bridge rectifier circuit.
6.3 Equipment 1. 2. 3. 4. 5. 6. 7. 8. 9.
Function Generator Digital Multimeter Oscilloscope Transformer 220V to 12V Diode 1N4007 Resistance 330 / 0.5W, 470, 680, 820, 1K, 2.2K, 3.3K, 4.7K, 6.8K, 10K,100K Capacitance 0.1uF,1uF,2.2uF,10uF,47uF,56uF,68uF,100uF,220uF,330uF Breadboard Connecting wires
6.4 Conduct of Lab 1. Students are required to perform this experiment using the equipment provided. 2. Students are required to work in a group specified by lab engineer. 3. In case some aspect of the lab experiment is not understood the students are advised to seek help from the course instructor, lab engineers, assigned teaching assistants (TA) and lab attendants.
6.5 Theory and Working The bridge rectifier uses four diodes connected as shown in figure 1. When the input cycle is positive as in figure 1, diodes D1 and D2 are forward-biased and conduct current in the direction shown. A voltage is developed across RL that looks like the positive half of the input cycle. During this time, diodes D3 and D4 are reverse-biased.
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Lab 06 Full Wave Bridge Rectifier
Figure 1 full wave bridge rectifier during positive half cycle D1 and D2 conducts When the input cycle is negative as in figure 2, diodes D3 and D4 are forward biased and conduct current in the same direction through RL as during the positive half-cycle. During the negative half-cycle, D1 and D2 are reverse-biased. A full-wave rectified output voltage appears across RL as a result of this action.
Figure 2 full wave bridge rectifier during negative half cycle D3 and D4 conducts
6.6 Performance Parameters for Two Pulse Rectifier Analysis The following parameters has been explained in the analysis of Half Wave Rectifier. 6.6.1.1
Peak Inverse Voltage (PIV) Peak Inverse Voltage (PIV) of half wave rectifier = VSMAX
6.6.1.2
6.6.1.3
Average Value of Output Voltages and Current 1 𝛱 2𝑉𝑚 𝑉𝐷𝐶 = ∫ 𝑉𝑚 sin(𝜔𝑡) 𝑑𝜔𝑡 = 𝑇 0 𝛱 𝑉𝐷𝐶 𝐼𝐷𝐶 = 𝑅 Average Diode Current ID
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=
IDC
2
Lab 06 Full Wave Bridge Rectifier
6.6.1.4
The rms Value of Output Voltages and Current 2
𝑉𝑟𝑚𝑠
1 𝛱 𝑉𝑚 √ ∫ (𝑉𝑚 sin(𝜔𝑡)) 𝑑𝜔𝑡 = = 𝑇 0 √2 Irms
=
Vrms
6.6.1.5 The Load Average and rms Power PDC
R
= VDC IDC =
Pac = Vrms Irms 6.6.1.6 Rectifier Efficiency η=
PDC PAC
4Vm 2 Π2 R Vm 2 = 2R
= 81%
6.6.1.7 Form Factor FF =
Vrms VDC
=1.11
6.6.1.8 Ripple Factor VAC = √FF 2 − 1 = 48.2% VDC 6.6.1.9 Power Absorbed By the Load RF =
Pload = Irms 2 R
6.7 Procedure: Without Filter 1. 2. 3. 4.
Connect the circuit on bread board as per figure 3. Connect the primary of the transformer to main supply i.e. 230V, 50Hz Starting from 330 Ω vary the resistance up to 100K Ω as mentioned in table 1. Connect the Multimeter at output terminals note down the Vac and Vdc as per given tabular form by varying resistance. 5. Disconnect load resistance and note down no load voltage Vdc (V no load) 6. Connect load resistance at 1KΩ and connect Channel – II of CRO at output terminals and CH – I of CRO at Secondary Input terminals observe and note down the input and output wave form of output voltage (VO) Output current (Io), diode 1 voltage (VD1), diode 3 voltage (VD3) and source current (IS) on graph sheet. 7. Calculate ripple factor
Equation 1 Ripple factor 6|Page
Lab 06 Full Wave Bridge Rectifier
8. Calculate Percentage of Regulation
Equation 2 Percentage Regulation
Figure 3 Full wave rectifier without filter
Sr.No
Load Resistance Ω
1
330 / 0.5 W
2
470
3
680
4
820
5
1K
6
3.3 K
7
4.7 K
8
6.8 K
9
10 K
10
100 K
No Load voltage_________________ % Of Voltage Output Voltage Ripple Factor Regulation 𝑉𝑎𝑐 𝑉𝑛𝑙−𝑉𝑓𝑙 Vac Vdc 𝑋 100 𝑉𝑑𝑐
Table 1 Observation for full wave rectifier without filter
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Lab 06 Full Wave Bridge Rectifier
𝑉𝑛𝑙
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Lab 06 Full Wave Bridge Rectifier
With Capacitor Filter 1. 2. 3. 4. 5.
Connect the circuit as in figure 4 and vary the capacitor. Connect oscilloscope at output to observe the change in ripple of output wave. Using oscilloscope measure average value (Vdc) of output waveform. Using oscilloscope observe and calculate Vac of output ripple according to table 4. Calculate ripple factor using equation and fill the table 4 given below. Output Voltage
S.No
C
1
0.1uF
2
1uF
3
2.2uF
4
10uF
5
47uF
6
56uF
7
68uF
8
100uF
9
220uF
10
330uF
Vr(max)
Vr(min)
Vr(p-p)=Vr(max)-Vr(min)
𝑉𝑎𝑐 =
𝑉𝑟(𝑝 − 𝑝)/2 √2
Table 2 Full wave rectifier using different filtering capacitor .
Figure 4 Full wave rectifier with capacitor filter
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Lab 06 Full Wave Bridge Rectifier
Vdc
Ripple Factor 𝑉𝑎𝑐 𝑉𝑑𝑐
Figure 5 Model wave forms for full wave rectifier
6.8 Troubleshooting Exercise Connect the circuit as in figure 3 observe the behavior of output waveform in following cases.
Diode short circuited 6.8.1.1 D1 Short Circuited Short the D1 using jumper wire and draw the output wave form obtained on oscilloscope. Write reason for distorted waveform.
Reason: ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ 6.8.1.2 D3 short circuited Short the D3 using jumper wire and draw the output wave form obtained on oscilloscope. Write reason for distorted waveform.
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Lab 06 Full Wave Bridge Rectifier
Reason: ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________
Diode open circuited 6.8.2.1 D1 open circuited Open the D1 and draw the output wave form obtained on oscilloscope. Write reason for distorted waveform.
Reason: ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ 6.8.2.2 D4 open circuited Open the D4 and draw the output wave form obtained on oscilloscope. Write reason for distorted waveform.
Reason: ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________
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Lab 06 Full Wave Bridge Rectifier
Full wave bridge rectifier with function generator 1. 2. 3. 4.
Connect the circuit as shown in figure 5. Generate 10V (p-p) sine wave using function generator. Observe and draw the output wave form. Give reasons for distorted output waveform.
Figure 5 Bridge rectifier with function generator
Reasons: ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________
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6.9 Student Learning Outcome ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________
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Lab 06 Full Wave Bridge Rectifier
