LED Voltage Calculator:
Enter the values of supply voltage, Vs(V), resistance in series, R(Ω) and current through the LED, I(A) to determine the value of LED voltage, Vled(V).
LED Voltage Formula:
The LED Voltage Calculator is a practical tool designed to compute the voltage across a Light Emitting Diode (LED) in an electrical circuit.
This calculation is fundamental in electronics when using LEDs to ensure they operate safely without exceeding their voltage rating.
The formula helps determine the actual voltage drop across an LED by accounting for the supply voltage, the current through the circuit, and the resistance in series with the LED.
LED voltage, Vled(V) in volts is calculated by the difference of supply voltage, Vs(V) in volts and the product of resistance in series, R(Ω) in ohms and current through the LED, I(A) in amperes.
LED voltage, Vled(V) = Vs(V) – R(Ω) * I(A)
Vled(V) = LED voltage in volts, V.
Vs(V) = supply voltage in volts, V.
R(Ω) = resistance in ohms, Ω.
I(A) = current in amperes, A.
LED Voltage Calculation:
- Calculate the voltage across an LED in a circuit with a 9V battery, a 330-ohm resistor, and an LED that requires 20 mA current:
Given: Vs(V) = 9V, R(Ω) = 330ohms, I(A) = 20mA = 0.02A.
LED voltage, Vled(V) = Vs(V) – R(Ω) * I(A)
Vled(V) = 9 – 330 * 0.02
Vled(V) = 9 – 6.6
Vled(V) = 2.4V.
- Determine the supply voltage across an LED if the LED voltage is 0.25V, the series resistor is 470 ohms, and the LED current is 25 mA:
Given: Vled(V) = 0.25V, R(Ω) = 470ohms, I(A) = 25mA = 0.025A.
LED voltage, Vled(V) = Vs(V) – R(Ω) * I(A)
Vs(V) = Vled(V) + R(Ω) * I(A)
Vs(V) = 0.25 + 470 * 0.025
Vs(V) = 12V.
Applications and Considerations:
- Electronics Hobbyists: Useful for DIY projects that involve LEDs to ensure correct resistor selection.
- Educational Use: Helps students understand the relationship between voltage, current, and resistance in simple circuits.
- Commercial Lighting: Critical in designing LED lighting systems to ensure optimal performance and safety.