Equipment:
You must make up a complete equipment list and have you instructor review it before you start.

Components:

• 4 - 1N4002 Diodes
• 1 - 1N751A Zener Diode
• 1 - 7805 and 7905 +5 Voltage Regulator
• 1 - 12 V Center Tapped Transformer
• 2 - filter capacitors, to be determined by your filter design
• RL = 16 kOhm
• Assorted resistors, to be determined from your design.

Objectives:

• To measure the output characteristics of your transformer
• To design, build and safely test a half wave rectifier
• To design, build and safely test a full wave rectifier
• To design, build and safely test a bridge rectifier
• To design, build and test a Zener 5.1V regulator circuit
• To design, build and test a +5 VDC regulated power supply
• To design using power ratings
• To measure ripple voltage and obtain the ripple factor

2.- The Turns Ratio

a.  Transformer Primary Voltage, V1 is given as 110 V_rms. Use the oscilloscope to measure Transformer Secondary
     Voltage,V2_rms.

b.  Express the primary voltage (V1) and secondary voltage (V2) in
     i) V_rms
     ii)V_peak
     iii)V_{peak to peak}
     iv)V_avg.

Note: Measure the values of V2_rms, V2_peak, V2_{peak to peak} and V2_avg from the Digital oscilloscope. However, the values of V1_peak, V1_{peak to peak} and V1_avg CAN ONLY BE CALCULATED from given equations in the ECE11 textbook, given V1_rms = 110 V_rms DO NOT attempt to measure V1!!

Place all information in Table # 1. Determine the turns ratio (V1/V2) of T1 and place this data in Table #1.

c.  Using digital oscilloscope, print out the Vout of secondary winding (V2). Label this plot Figure A - Unloaded
    Transformer Secondary Waveform. Then disconnect Transformer from the AC outlet.

3.- Testing Positive Rectifiers

1. Construct the circuit of Figure #1. Test the circuit for a possible short to ground with an ohm meter. Correct any wiring errors and test again. Connect T1 to an AC outlet. Measure and print the waveform across RL. Disconnect T1 from the AC outlet! Plot and label the waveform Figure 1A -- Wave Form Across RL In Half Wave Rectifier

Label the axis and any details in the plot.

2. Construct the circuit of Figure #2. Test the circuit for a possible short to ground with an ohm meter. Correct any wiring errors and test again. Connect T1 to an AC outlet. Measure and print the waveform across RL. Disconnect T1 from the AC outlet! Plot and label the waveform Figure 2A -- Wave Form Across RL In Full Wave Rectifier.

Label the axis and any details in the plot.

3. Construct the circuit of Figure #3. Test the circuit for a possible short to ground with an ohm meter. Correct any wiring errors and test again. Connect T1 to an AC outlet. Measure and print the waveform across RL. Disconnect T1 from the AC outlet! Plot and label the waveform Figure 3A -- Wave Form Across RL In Bridge Rectifier.

Label the axis and any details in the plot.

4.- Zener Regulator Design

1. (Lab HW) What is the special characteristic of Zener Diode compare to other diodes that makes it very useful in the design of voltage regulators


2. (Lab HW) Design Zener regulator circuit that has the specifications below:
• Vin: 8.13V_DC + 1.87 V_DC
• Vout(unloaded): 5.1 V_DC+ 5 %
• Vout(loaded): 5.1 V_DC+ 5 %
• Type of Load: resistive, 300 Ohms
Hint: The reference for the design can be found in the textbook, Chapter 3 section 3.6 - "Design of the Zener Shunt Regulator". The Vz, Iz and Rz can be obtained from 1N751A datasheet (In PDF format). Click HERE to go to the datasheet. Draw and label the schematic of this circuit Figure #1 - 5.1 V Zener Regulator Circuit. Compute the output voltage corresponding to Vin_min and to Vin _max Use ORCAD to simulate your design.


3. Assemble your design in part (b).


4. Verify the correct operation of your design in part (b). Take enough readings of Vout to prove this. Start withVin_min and take enough reading until Vin_max . Write down the values for the Vin and Vout and put it in Table #1 - 5.1V Zener Regulator Reading.


5. Compute the load regulation.

5.- + 5 / -5 VDC Power Supply

1. (Lab HW) Design a +5 V_DC regulated power supply that has the specifications below.


• Line input voltage: 120 V_rms @60 Hz
• Regulated output voltage: +5 V_DC+ 5%
• Load: resistive
• Power Consumed by the Load: 175 mW_DC
• Ripple: minimum

Note: The reference for the design can be found in the textbook: Chapter 3 section 3.7 Figure 3.36. The load can be calculated using P= V²/R. Draw and label the schematic Figure # 2 - +5 V_DCregulated power supply. Use ORCAD to simulate your design. The data sheet for +5V voltage regulator (LM7805) is HERE and data sheet for -5V voltage regulator (LM7905) is HERE.

2. Build your design.


3. Print out the output voltages (+5V and -5V) of your design and measure the ripple voltage. What is the frequency of the ripple?

6.-  Analysis of Results

Positive Voltage Rectifier Circuits
a. Compare the measured results of each type of positive rectifier to those simulated results obtained using ORCAD.
    Provide explanation if the measured results are different from ORCAD simulation.
b. Explain the detail characteristics of each positive rectifier and possible application. The example of detail characteristic is
    the different PIV for different rectifiers.
c. Which one is better, Full Wave or Bridge Rectifier? Explain.

Zener Regulator Design
a. Compare the Vout reading for 5.1 V Zener Voltage Regulator to the ORCAD simulation. Did you produce the
    expected result? Explain.

+5/-5 V DC Power Supply
a. Compare the printout of the output voltages to the ORCAD simulation. Did you produce the expected result? Explain.
b. In the final project, you are required to produce your own + 12 V Power Supply. Which components (Part Numbers) in
    the design will you have to change to get + 12?

Revised from the original version by Faisal Mohd Yasin, cepus@seas.gwu.edu, September 21st, 2002