A properly doped p-n junction diode which works inthe breakdown region without damging itself is called a zener diode. It is represented by.
Zener diode as a voltage regulator
A Zener diode can be used as voltage regulator or voltage stabliger to provide a constant voltage from a source voltage may fluetuate over a wide range.
When the input voltage increase, resistance of the zener diode decreases and hence the current through the diode increases to high value. As a result of this, large voltage drop occurs the dropping resistance R2. Hence the output voltage across R1 is maintained to the desired value. when the input voltage decreases, current through the diode also decreases. So now small voltage drop takes plane across the resistance R2 and the output voltage across R2 is maintained at the desired constant value.
Thus we get a constant voltage inspite of the fluetuating input voltage.
Hence zener diode acts as a voltage regulator.
