Lab 5 Rectifiers and DC Regulators

Outcome of this lab:
1. Be familiar with the Rectifiers and DC regulators.
2. Be able to design a DC power supply. .

Instructions:

Task 1.
1.1 Build the following circuit in LTSpice, report the diode 'built-in' potential.



1.2 Modify the built-in potential to 0.6 V. Show the input-output curves before and after you change the built-in potential.
(hint: .model D D(Vfwd=0.6))

1.3 Use a the diode: 1N 5767 and a 1k resistor to build this circuit (can be 1.1 k or 1.2 k ohms) on a breadboard. Use the oscilloscope to show the input and the output.
Report the 'built-in' potential of this diode.

Task 2
1.1 Build the following circuit in LTSpice, report the input and output signal



1.2 Build this circuit on a breadboard and report the results.

Task 3
3.1 Build the following circuit in LTSpice and on a breadboard. Explain the results for credit.



3.2. Build the following circuit in LTSpice (Note: only in LTSpice). Model the Zener diode by this script: '.model D D(BV=10)', to define the breakdown voltage to 10 V. The purpose of using zener diodes is to protect your circuit. Whenever your input is suddenly larger than 10V, the zener diodes will just breadown and 'Clamp' the voltage at 10 V.



Use the Zener diode 1n5230, find the Vz of this diode in the datasheet and then verify on a breadboard using the circuit above. Show the input and output on the scope.
(You need to pick up a proper Vpp for the sinewave to see the 'Clamping Circuit' output).

Task 4
Build the following circuit in LTSpice and on a breadboard. Report the results and explain why.
(This circuit is called 'voltage doubler'. It can be used to provide a high-DC voltage).












-------------The end of the lab