The LED: An In-Depth Guide

Last Edited Dec 9 2011
Thanks for all the feedback everybody :D

Sure, we all know a little about this little light, but what is it? What makes it tick? Why are they so efficient? Just what exactly is going on in those little things? These questions, and many more, are about to be answered.

You're free to skip ahead as you feel necessary, but whether you're an electronics newbie, a regular LEDer, or an experienced engineer, chances are you're probably going to learn something new in every step. This guide is a massive collaboration of everything I have learned over the years of using these (Okay, a little over ~2 years, but, hey, I obsess) and as it is an Instructable, I am always ready to listen and improve from ("constructive") criticism. So let's get to it!

Step 1 What are they?

LEDs, or Light Emitting Diodes, are an electronic lighting device. They are sweeping the world as a cheap, efficient, and overall cool new way of lighting. They're used in just about everything nowadays, and are on the verge of completely replacing regular lightbulbs. LEDs are fascinating little devices that anyone, age 6 to 60, can learn to use.

Comments

[BrunoG]

(removed by author or community request)

[stusan]

"*Silicon - basically, refined charcoal or graphite." _ Ummm, nope. Silicon, an element, is derived from sand (silicon dioxide). Charcoal and graphite are made of carbon. Some LED "chips" are made from a crystalline combination of silicon and carbon called silicon carbide. Most LED "chips" are most commonly made from crystals of Gallium Arsenide, often with Indium. Other elements are used to "dope" the crystal for desired properties.

[Coodude26]

(removed by author or community request)

[d-lite]

Calling LED material Silicon Carbide is anything but 'minor'.

This guide is more guesswork than report. Do more research before you call something "In-depth"! This may help: http://en.wikipedia.org/wiki/Led

[Coodude26]

This issue has been addressed, and the article has been revised. The article is also now under the Attribution license.

[thebobin8r]

devans0 is right, this is put together very well. I'm really just starting out dabbling in programming and creating my own electronics and I found it very helpful. Thanks!

[Coodude26]

Thank you so much. Comments like these have really made writing this worth my time, and I'm glad to see I've helped someone who is in my position from a few years back :D

[fignutz28]

Hey there! Amazing info, and I have been wanting to learn how to build my own l.e.d fixture for my Salt Water Aquarium! I would LOVE to get any feed back on...Either a great place to purchase L.E.D's for a good price that could be used for this application, or possibly a website ( or if you can help in anyway I would appreciate that to the fullest ) to where you can learn about the different fixtures o build! Thank you again, and God Bless,

[Coodude26]

Hi! I couldn't tell you where you could buy LEDs in person, but the place I buy from online is called DealExtreme. They're run out of Hong Kong, but they're trustworthy and they take PayPal. Expect a 2.5 week shipping time, depending on where you live.

As for fixtures, I've never built my own but I'm sure google would bring up a few results. Try searching "DIY LED fixture", but be aware that you'll have to solder them together. If you want a great video of how to solder properly, search YouTube for"How and why to solder correctly".

Hope this helps!
-C

[johnsheppard]

dam good information , well done ,, i am planning on building my led cube soon (any one know where i can buy inexpensive 5mm leds) thx ... keep up the good work.

[dog digger]

I made a simular guide to this.
Anyway dealextreme has very cheap LEDs.
about $1.25 for a pack of 10. And they are bright

[Jeevendra]

This is awesome stuff... Thank you. It will help me to get started on things.

[Bama7474]

Enjoyed the read...Have one question, can the power source be AC when using LED's or does it have to be converted to DC...Everything I've read deals with DC...I know there are AC LED applications, for example the pic of the replacement light above, but is it getting converted to DC somewhere in the mix?  Thanks.

[Dipankar]

LED's can also be used with AC 220 or 110 volts.
See my Instructable "LED Chandelier" and "Spiral LED Chandelier" ( with AC Transformers)
LED's can also run of  AC with capacitors and resistance.

[devans0]

 This is an unusually complete DIY.  I was weak on solder skills and the circuit calculator really sped up my RV light project.  Thanks!

[johnnytombstone]

Thanks for the simple explanation. We see them everywhere, and some burn 24/7. Good insight.

[Jack A Lopez]

Hey, uh, Coodude, I was wondering about the "published" status of this 'ible:

The ible itself says it was published on Aug 7, 2009. Here:
http://www.instructables.com/id/The-LED-An-In-Depth-Guide/

At the same time your, "you" page doesn't list it under your ibles. Here:
http://www.instructables.com/member/Coodude26/

Is this another glitch in the matrix? I mean another instance of the Instructables software/moderation screwing up again? Just wondering. BTW, I'm not anyone who has the power to fix these things, and I'm not sure who here does.

[b-stro]

When the silicone gets "excited", electrons build up on an energy level of the silicone atoms that cannot sustain a high number of electrons. The electrons then try to drop to a lower energy level in the silicone, but instead drop to an energy level in the "golf club" - usually a metal with a similar energy level layout. In doing so, the electrons give off energy (as light) so they fit into the lower energy level.

[insmac]

I bought my first one in, oh about 1975 or so... They have recently taken off as a area lighting device, but, they have been used by off grid'ers for years as well.

[Coodude26]

In case you didn't notice, this 'ible isn't published yet, but thanks for the info. How did you find this, anyway?

[insmac]

Didn't do anything special, was just browsing through instructables and it came up with other LED articles.

[i0scan]

Great instructable! You may have to get some thicker skin though man. This is the internet and helpful or hurtful comments are always going to be made by someone.

[S1L3N7 SWAT]

LED's aren't exactly "new." But they have gained popularity in recent years.