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Friday, May 11, 2012

Zener Diode voltage regulator (Basic Circuit) !

This well known circuit requires one Zener diode. The circuit works as the input voltage increases the current through the Zener increases but the voltage drop remains the same and as a result the voltage drop across the resistance increase (IR.R) in this amount (Vin -Vz)

Using iCircuit App for iPhone

Its important to pay attention to the power rating of the Zener and the Resistor, matching them to the current that need to be delivered to the load.
ex: If the output Load (R-Load) needs 100mA of current then the power rating of the Zener should be 1W at least (100mA x 10V). Similarly with the resistor (R) the power rating should at least equal the voltage drop across the resistor times the current output (5 x 100mA) which gives us 500mW.