Question

Design a zener regulator for the following specifications: output voltage ,V₀=5V, load current,IL =20mA,input voltage , $V_i$= 12V± 3V, zener wattage ,$P_z$=500mW

Answer 1

Answer:

Rs = 83.3 Ohm and RL = 250 ohm

Explanation:

The maximum rated current of Zener diode is 100 mA which means that at a current of 120 mA will flow through the series resistor when input is maximum at 15 V. The voltage across the series resistor will be (15-5) = 10 V. So a series resistor of Rs = (10/.12) = 83.3 Ohm is required.

The load resistor has IL = 20 mA and Vo = 5 V so its value = (5/0.02) = 250 Ohm.