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Kuinka laskea L E D Resistor

Mikä on L E D Resistor?

Calculates resistor value needed to limit current through an LED to safe operating levels. Prevents LED burnout and extends lifespan.

Kaava

Formula: R = (V - Vf) ÷ I
R
(V - Vf) ÷ I — (V - Vf) ÷ I
V
V value — Variable used in the calculation
Vf
Vf value — Variable used in the calculation
I
I value — Variable used in the calculation

Vaiheittainen opas

  1. 1Supply voltage (V)
  2. 2LED forward voltage (typically 1.5-3.5V)
  3. 3Desired LED current (typically 2-20mA)
  4. 4Formula: R = (V - Vf) ÷ I
  5. 5Select nearest standard resistor value

Ratkaistut esimerkit

Syöte
LED 2V, supply 5V, 20mA
Tulos
150ohm resistor

Yleisiä virheitä vältettäväksi

  • Using incorrect LED forward voltage for color
  • Not accounting for voltage supply variation

Usein kysytyt kysymykset

What happens without current limiting resistor?

LED draws maximum current, burns out immediately, and can damage power supply.

How do I select resistor wattage?

Power = V × I; select resistor rated 2× calculated power for safety margin.

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Asetukset

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