The formula to calculate the current limiting resistance (R) is:
\[ R = \frac{V_s - V_f}{I_d} \]
Where:
Let's say the supply voltage is 12 V, the forward voltage is 2 V, and the desired current is 0.02 A. Using the formula:
\[ R = \frac{12 - 2}{0.02} \]
We get:
\[ R = \frac{10}{0.02} = 500 \]
So, the current limiting resistance (\( R \)) is 500 Ω.
A current limiting resistor is a resistor used to limit the amount of current that flows through a circuit. This is particularly important in circuits with LEDs or other components that can be damaged by excessive current. By placing a resistor in series with the component, the current is limited to a safe level, ensuring the longevity and proper functioning of the circuit. The value of the resistor is chosen based on the supply voltage, the forward voltage of the component, and the desired current.