Running Head: Full Wave Bridge Rectifier
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Rectifier Fundamentals
Filtered Full Wave Bridge Rectifier
In this lab you will build circuits used to convert alternating current to pulsating direct current
using semiconductor diodes.
In this section we will look at a full wave bridge rectifier circuit used to convert alternating
current to pulsating direct current.
Niagara College Photonics Engineering Technology
No sector of business or industry remains untouched by photonics, the science of generating and
harnessing light. The Photonics Engineering Technology program at Niagara College
encompasses optics, lasers, electro-optics, spectroscopy and electronics technology.
Full Wave Bridge Rectifier
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Document content developed by:
Alexander McGlashan
Niagara College of Applied Arts and Technology
School of Technology, Department of Photonics
Full Wave Bridge Rectifier
Purpose
In this section we will look at a full wave bridge rectifier circuit used to convert alternating
current to pulsating direct current.
myDAQ Full Wave Bridge Rectifier using LEDs
Parts Required:
1 – 1.5kΩ resistor
4 – Red LED
1. Construct the following circuit
2. Launch the function generator from multisim or the NI ELVISmx Instrument Launcher.
 Set the frequency to 200mHz
 Set the amplitude to 10Vpp
 Select the Sine waveform
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Full Wave Bridge Rectifier
3. Click run and observe the action of the LEDs.
4. Based on your observations of the LED and the knowledge that the source voltage is a
10Vpp sine wave, describe what you think is occurring to the current through the LEDs
during one complete cycle of the source voltage.
 Draw a schematic of the circuit and trace the flow of current through the circuit
for one complete cycle of the source voltage.
Multisim Simulation and myDAQ
1. Open the Multisim file Full Wave Bridge Rectifier.ms12
2. In the simulation, wire inputs AI 0 across output AO 0 (measuring our source voltage
with Channel 0) and AI 1 across the load resistor (measuring the load voltage with
Channel 1, which will also be proportional to the current through the circuit).
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Full Wave Bridge Rectifier
3. Open the function generator and oscilloscope.
 Set the frequency to 60Hz
 Set the amplitude to 10Vpp
 Select the Sine waveform
4. Run the simulation and adjust the scope settings such that one cycle of the source is
clearly visible.
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Full Wave Bridge Rectifier
5. Since the voltage displayed on Channel 1is directly proportional to the current in the
load, we can see that current is flowing through the load during both half cycles of the
source voltage.
 Measure and compare the frequency of Channel 0 and Channel 1
 Measure the peak voltage of Channel 0
 Measure the peak voltage of Channel 1
 Calculate the peak load current
 What is the voltage drop across the Light Emitting Diodes in the bridge?
 Is the direction of current through the load the same or different during each half
cycle? (Hint: Look at the polarity of the load voltage during each half cycle)
6. On the real myDAQ, wire inputs AI 0 across output AO 0 and AI 1 across the load
resistor as you did in the simulation.
7. In the Instrument Control for your generator and scope, make sure to set them both to
the real myDAQ device (not the simulation).
8. Run the instruments and compare the real and simulated results.
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Full Wave Bridge Rectifier
9. Reverse each LED in your circuit so they are facing in the opposite direction and rerun
the circuit.
 How is the load voltage and current in the circuit affected?
 Why does this happen?
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Full Wave Bridge Rectifier
Multisim Simulation and myDAQ Half Wave Rectifier using a Rectifier Diode
Parts Required:
1 – 1.5kΩ resistor
1 – 2.2kΩ resistor
4 – 1N400x rectifier diode
1. Replace the LEDs in your simulation with 1N4001 rectifier diodes as shown
2. Open the function generator and oscilloscope.
 Set the frequency to 60Hz
 Set the amplitude to 10Vpp
 Select the Sine waveform
 Run the simulation
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Full Wave Bridge Rectifier
3. Note the difference between the load voltage in this circuit (using a rectifier diode) and
that of the previous circuit (using an LED).
 Measure and compare the frequency of Channel 0 and Channel 1
 Measure the peak voltage of Channel 0
 Measure the peak voltage of Channel 1
 Calculate the peak load current
 What is the voltage drop across the diodes in the bridge?
 What are some possible advantages to this circuit compare to the half wave rectifier
circuit?
4. In the real circuit, replace the LEDs with 1N400x rectifier diodes.
 Given the load current calculated in the last step, is the myDAQ capable of
sourcing enough current for this circuit?
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Full Wave Bridge Rectifier
5. Run the real circuit and observe the results
6. We can clearly see here that we have exceeded the maximum current capacity of the
myDAQ.
7. Replace the 1.5 kΩ load resistor with a 2.2 kΩ resistor and rerun the experiment
 Measure and compare the frequency of Channel 0 and Channel 1
 Measure the peak voltage of Channel 0
 Measure the peak voltage of Channel 1
 What is the peak voltage drop across the bridge diodes?
 Calculate the load current.
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Full Wave Bridge Rectifier
8. Using the scope Log function (located in lower right corner of the scope instrument
panel) save your data and then import it into a spreadsheet program.
 Create a data series calculating the Load Current
 Plot Channel 0 (Source Voltage)
 Plot Channel 1 (Load Voltage)
 Plot Load Current (use a secondary y-axis scale)
 Label all elements
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