EXPERIMENT No.3 Zener Diode

EXPERIMENT No. 3

Components: 2 x resistors, 1 x 5V1 400mW Zener diode (Z_D).

Exercise: Obtain a breadboard, suitable components from your tutor and build the following circuit.

Fig 6

For R= 100Ω and RL= 100Ω, Vs= 12 V.

What is the value of Vz?

Vz = 5v

Vary Vs from 10V to 15 V

What is the value of Vz?

Vz = 5.06v

Explain what is happening here

At 10v the value of Vz is 4.77v and as I increase the Vs to 15v the value of Vz is 5.06v. The input Vs to the Zener diode isnt stable but the zener diode keeps a fixed voltage output. It breaks down 15v to 5v.

What could this circuit be used for?

This circuit could be used for powering a device connected to a 12v supply that requires less voltage say 5v and keep it fixed. 

Reverse the polarity of the zener diode.

What is the value of Vz? Make a short comment why you had that reading.

The value of Vz is 0.7V in the forward Bias because it acts as normal diode in this direction which requires less voltage to turn it on.