How to Choose the Correct Resistor Value for an LED Circuit
- 5 hours ago
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How to Choose the Correct Resistor Value for an LED Circuit
To safely power an LED, you must include a current-limiting resistor.
The basic formula is:
R = (Vs – Vf) / I
Where:
R = resistor value
Vs = supply voltage
Vf = LED forward voltage
I = desired current
Example:
If using a 5V supply, an LED with 2V forward voltage, and 20mA current:
R = (5 − 2) / 0.02R = 150 ohms
Using the correct resistor prevents LED damage and ensures consistent brightness.
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