Calculadora de Resistencia para LED Gratis
Calcula la resistencia limitadora para proteger un LED. Ingresa voltaje de fuente, voltaje del LED y corriente.
Required Resistance
150.0 Ω
Required Resistance vs Supply Voltage
Fórmula
## How to Size a Resistor for an LED An LED needs a series resistor to limit current. ### Formula **R = (V_supply - V_led) / I_led** Where: - **V_supply** = Source voltage - **V_led** = LED forward voltage drop - **I_led** = Desired LED current (commonly 20 mA) Power dissipated in the resistor is **P = (V_supply - V_led) x I_led**.
Ejemplo Resuelto
Drive a red LED (2.0 V forward) at 20 mA from a 5 V supply.
- 01Voltage across resistor = 5 - 2.0 = 3.0 V
- 02Current in amps = 20 / 1000 = 0.02 A
- 03R = 3.0 / 0.02 = 150 ohms
- 04Power = 3.0 x 0.02 = 0.06 W = 60 mW
Preguntas Frecuentes
What happens without the resistor?
The LED draws excessive current and burns out within seconds.
How do I know my LED forward voltage?
Check the datasheet. Typical: red 1.8-2.0 V, green 2.0-2.2 V, blue/white 3.0-3.3 V.
What if the exact resistor is unavailable?
Round up to the next standard value. Slightly higher resistance is safe for the LED.
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