This CalcTown calculator calculates the Input Resistance (R_{i}) in a Zener Diode voltage regulator circuit so that the designed specifications of input voltage and load resistance can be met.

*Please note that it has been assumed that the minimum Zener Current is 10% of the maximum Zener Current. Although in more practical applications, it is usually 20-30%.

**Out of the two resistance values shown in the output, please choose the one with lower magnitude and neglect the higher value.

Zener Diode circuit design Calculator

Maximum Input Voltage (V_{PS} (max))

V

Minimum Input Voltage (V_{PS} (min))

V

Maximum Input Load Current (I_{L} (max))

mA

Minimum Input Load Current (I_{L} (min))

mA

Regulated Output Voltage (V_{Z})

V

CALCULATERESET

Result

Maximum Zener Current

mA

Ri

K-Ohm

Ri

K-Ohm

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where

V_{PS} = Voltage of the Power Source

I_{L }= Current Flowing through the Load Resistance

I_{Z }= Current Flowing through the Zener Diode

V_{Z} = Zener Voltage

I_{Z}(max)= Maximum Zener Current

and Load Resistance and Power Source Voltage are variable over a certain range.