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How to find voltage and current of LED

How to find voltage and current of LED

I got this question from Awajigbana:

[Awajigbana]: Please sir how can i know the voltage and the current ratings of a
LED. Also, how is the resistor of a LED choosed. Thanks

[Oyvind]: There are a few different ways:

1. The easiest way is to look it up in the datasheet.
2. You could find the LED voltage by using a multimeter with diode function.
3. You could connect a battery to the LED and a potentiometer. Start with a high resistance on the potentiometer and gradually decrease it until you have an nice brightness. Then measure the voltage over the LED, and measure the current going through the circuit.


Here’s how to choose a resistor for your LED:

This is basic knowledge that is very useful to have. In my eBook “Getting Started With Electronics” you’ll learn the basics, but only the stuff you really need to build things with electronics.

Here’s the link:

Keep on Soldering!

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