A 24 V, 600 mW Zener diode is used for providing a 24 V stabilized supply to a variable load. If the input voltage is 32 V, calculate (i) the value of series resistance required and (ii) diode current when the load is 1200 Ω.
A 24 V, 600 mW Zener diode is used for providing a 24 V stabilized supply to a variable load. If the input voltage is 32 V, calculate (i) the value of series resistance required and (ii) diode current when the load is 1200 Ω.
Given V_{0} = 24 V, V_{i} = 32 V, P_{Z} = 600 mW
The load current, I_{L} =\frac{V_{0}}{R_{L}}=\frac{24}{ 1200} = 20 mA
Max. Zener current, I_{z(max)} = \frac{600 × 10^{– 3}}{24} = 25 mA
R_{max} = \frac{V_{i} – V_{0}}{I_{L(min)} + I_{z(max)}}=\frac{32 – 24}{(20 + 25) × 10^{– 3}} = \frac{8}{45 × 10^{– 3}}= \frac{1600}{9} = 177.78 Ω