LED Resistor Calculator
Calculate the correct resistor value for LED circuits
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Enter your LED specifications and power supply voltage
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LED Circuit Information
Guidelines for LED resistor calculations
Tips for LED Circuits:
- Always use a current-limiting resistor with LEDs
- Choose a resistor with adequate power rating
- For safety, use the next higher standard resistor value
- Check the LED datasheet for exact specifications
Formulas:
- Series: R = (Vsupply - (Vled × n)) ÷ Iled
- Parallel (shared resistor): R = (Vsupply - Vled) ÷ (Iled × n)
- Power: P = Voltage Drop × Current
For power resistors, choose one with at least twice the calculated power rating for safety and longevity. Standard resistor values follow the E12 series.
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