Zener diode

#1

Can you explain how zener diode acts as voltage regulator?

#2

Hi,

Forward Bias occurs in normal diode as they only pass the current in one direction only. In the other situation of making use of reverse bias, even with the increase in voltage, there’s no current unless the barrier is removed/breaks. However, when making use of Zener diode, the breakdown occurs at a very low voltage and thus it’s made used in reverse bias.

Now, to answer it’s use/application as a voltage regulator. The voltage across zener diode is equal to breakdown voltage and is equal. Say a zener diode that breaks down at 3V will have 3V across it even if you apply 5V to it. The remaining 2V will be across the resistor in the series. So, any/all load parallel to the zener diode will have the constant 3V across it. Thus, with the use of zener, you’ve a constant voltage source. And, that’s how a zener diode acts as a voltage regulator.

You can watch this video to look at a practical example here: