1. What is a Current Through LED Calculator?

Definition: This calculator determines the current flowing through an LED when connected in series with a current-limiting resistor.

Purpose: Helps electronics enthusiasts and engineers properly design LED circuits to prevent damage from excessive current.

2. How Does the Calculator Work?

The calculator uses Ohm's Law formula:

Where:

• \( I \) — Current through LED (amperes)
• \( V_{supply} \) — Power supply voltage (volts)
• \( V_{LED} \) — LED forward voltage drop (volts)
• \( R \) — Series resistance (ohms)

Explanation: The voltage across the resistor (supply minus LED voltage) divided by resistance gives the current.

3. Importance of LED Current Calculation

Details: Proper current calculation ensures LEDs operate within safe limits, preventing premature failure while achieving optimal brightness.

4. Using the Calculator

Tips: Enter supply voltage, LED voltage (typically 1.8-3.3V depending on color), and resistor value. All values must be > 0 except LED voltage which can be 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical LED forward voltage?
A: Red LEDs ~1.8-2.2V, Blue/White ~3.0-3.4V. Check your LED's datasheet for exact value.

Q2: What's a safe current for standard LEDs?
A: Most 5mm LEDs handle 20mA maximum, with 10-15mA being typical operating current.

Q3: What if my calculated current is too high?
A: Increase the resistor value to reduce current. Recalculate to verify.

Q4: Why subtract LED voltage from supply voltage?
A: The LED drops a fixed voltage; only the remaining voltage appears across the resistor.

Q5: Can I use this for multiple LEDs?
A: For series LEDs, sum their voltages. For parallel, calculate each branch separately.