• Skip to content
  • Skip to primary sidebar
  • Skip to footer

Build Electronic Circuits

Electronics explained in a simple way

  • About Me
  • Articles
  • Products
  • Contact

How to find voltage and current of LED

August 17, 2015 By Øyvind Nydal Dahl 5 Comments

How diodes work - right directionI 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:
https://www.build-electronic-circuits.com/current-limiting-resistor/

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:
https://www.build-electronic-circuits.com/products/ebook-2nd-edition

Keep on Soldering!
Oyvind

Filed Under: Mail Archive

Reader Interactions

Comments

  1. Sidhu Burre says

    August 23, 2015 at 11:16 am

    Nice Article according to readers opinions. I have downloaded your e-Book it’s good for me. Thank you..

    Reply
  2. Aaron says

    September 2, 2015 at 2:19 pm

    I don’t have the data sheet but I have about 50+ LEDS all sizes and colors. Since I don’t know the ratings is there a general rule of thumb on what size resistor to use?

    Aaron

    Reply
    • admin says

      September 4, 2015 at 10:50 pm

      Hey, if the’re standard LEDs they probably have around 2V voltage drop. If you’re using a 9V battery you can try 330 Ohm. Here’s how to calculate it:
      http://www.build-electronic-circuits.com/current-limiting-resistor/

      Cheers!
      Oyvind

      Reply
  3. Aaron says

    September 2, 2015 at 2:22 pm

    BTW I am really interested in building a 1w – 1.5w AMP for my phone/mp3 player do you have any plans on that or anywhere that can explain to me how to build one? I see a lot of sites that give away plans but they don’t explain where to add the potentiometer or power, etc and I am brand new to the world of electronics and i have bought just about every necessary tools to do stuff with since i have this new passion.

    Reply
    • admin says

      September 4, 2015 at 10:50 pm

      Hey,

      you can check out this one: http://www.build-electronic-circuits.com/amplifier-circuit-diagram/

      Cheers!
      Oyvind

      Reply

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Primary Sidebar

Most Popular:

  • Basic Electronic Components Used in Circuits
  • How To Choose Types of Solder to Use For Electronic Circuits?
  • Blinking LED Circuit with Schematics and Explanation
  • How Transistors Work - A Simple Explanation
  • The Simple Guide To Learning Electronics For Beginners

Search:

Privacy & Cookies: This site uses cookies. By continuing to use this website, you agree to their use.
To find out more, including how to control cookies, see here: Cookie Policy

Footer

Site:

Home
About
Blog
Contact

Social:

Facebook
Twitter
YouTube
Google+

Copyright © 2019 · Dahl Technology · Terms and Conditions