Equipment:
You must make up a complete equipment list and have your 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
• Resistors

 

• 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

1.- Zener Regulator Design

1. (HW) What is the special characteristic of Zener Diode compare to other diodes that makes it very useful in voltage regulator application.
2. (HW)Design Zener regulator circuit that has the specifications below.
 
• Vin: 8.13 V_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:  You can look for the way to design the circuit in the textbook; Chapter 3 - "Design of 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 value.

2.- + 5 / -5 VDC Power Supply

(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

 
You can design this power supply using Full-Wave Rectifier or Bridge Rectifier.  Please look for more information in the textbook: Chapter 3.  You can find the Resistance(Load) value using P= V²/R.  Draw and label the schematic Figure # 2 - +5 V_DC regulated power supply.  Use ORCAD to simulate your design.  The data sheet for LM7805 is HERE and data sheet for LM7905 is HERE.
 
1. Build your design.

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

3.-  Analysis of Results

Zener Regulator Design
a.  Compare the Vout reading for 5.1 V Zener Voltage Regulator to the ORCAD simulation.  Did you produce the
     result that you want?  If not, why?
b.  If you are asked to design for a 12V regulator circuit,  which component in the design that you must change to achieve
     that?

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