1. What is the LED Current Equation?

The LED current equation calculates the current flowing through an LED in a simple series circuit with a current-limiting resistor. It's based on Ohm's law and accounts for the LED's forward voltage drop.

2. How Does the Calculator Work?

The calculator uses the LED current equation:

Where:

• \( I \) — LED current (Amperes)
• \( V_s \) — Supply voltage (Volts)
• \( V_f \) — LED forward voltage (Volts)
• \( R \) — Resistance (Ohms)

Explanation: The equation subtracts the LED's forward voltage from the supply voltage, then divides by the resistor value to calculate the current through the circuit.

3. Importance of LED Current Calculation

Details: Proper current calculation is essential for LED circuit design to ensure optimal brightness, prevent LED damage from excessive current, and extend LED lifespan.

4. Using the Calculator

Tips: Enter supply voltage in volts, forward voltage in volts, and resistance in ohms. All values must be positive, and supply voltage should be greater than forward voltage for valid results.

5. Frequently Asked Questions (FAQ)

Q1: What is typical forward voltage for LEDs?
A: Typical forward voltages range from 1.8-3.3V for most common LEDs, depending on color and type.

Q2: Why is a current-limiting resistor necessary?
A: LEDs have non-linear IV characteristics and can be damaged by excessive current. The resistor limits current to safe operating levels.

Q3: What is a safe current for typical LEDs?
A: Most standard LEDs operate safely at 10-30mA, but always check the manufacturer's specifications.

Q4: Can this calculator be used for multiple LEDs?
A: This calculator is designed for single LED circuits. Multiple LED configurations require different calculations.

Q5: What if my calculated current is negative?
A: A negative current indicates that the supply voltage is less than the forward voltage, meaning the LED won't light up.