Experiment No.3 - resistors and diodes

In this experiment we where given 2 resistors and a 5v1 400mW Zener diode and built a circuit.


R= 100 ohms
RL = 100 ohms
Vs = 12v , 10v , 15v

value of Vz = 4.94v
value of Vz = 4.69v
Value of Vz = 5.07v

As the supply voltage drops ans increases the zener diode should hold 5.1v but as it is a cheap zener diode this does not happen.

This type of circuit would be used for voltage regulation

Then I reversed the polarity of the zener diode,

Now the value of Vz is .84v, thsi is because this is the foward rated voltage drop of the zener diode.