Several people on these forums ask “How do I wire LEDs?” I decided I would write a brief tutorial so they will understand how to wire and the different methods of wiring. I will also explain the resistor calculator because it seems some people don’t understand how to use it. Let’s begin with the various wiring methods.

There are three different wiring methods. These methods are single (for one LED), series (for multiple LEDs) and parallel (for multiple LEDs). I am only going to talk about series and parallel circuits.

SERIES

When wiring in series the voltage of the source is dispersed equally throughout all of the LEDs. In order to find out how much power will be going to each LED you divide the voltage of the source by the number of LEDs. In a hypothetical situation, we have a 12V source and 6 LEDs (each requiring 2V to run off of). Divide the voltage source by the number of LEDs and you will get 2V, which means that 2V will be going to each LED. Great, each LED works perfectly and has the required voltage needed to run.

What happens when you have 3 LEDs (requiring 3.7V to run) and a 12V source? You will have too much power going to each LED. Divide 12V by 3 (LEDs) and you will get 4V going to each LED. Because there will be to much power going to each LED you will most likely smell something burning and will have to go out to buy a new LED. To fix this problem a little thing called a resistor was invented. A resistor is a “circuit component which offers resistance to the flow of electric current. A resistor also has a powerhandling rating measured in watts, which indicates the amount of power which can safely be dissipated as heat by the resistor.” In order to figure out what kind of resistor you will need you will need to know several things about the LED and the voltage source:

A) What is the voltage of the power source?
B) How many LEDs will you be wiring?
C) What wiring method will you be using?
D) What is the voltage drop of the LED (How much power does it take to run it)?
E) What is the recommended milliamps (mA)?

Once you know these things you will be able to use a resistor calculator to calculate the resistor that you need (I will go into more detail about this later).

When wiring LEDs together in series you wire from the - leg on one LED to + leg on another (the longer leg on the LED is the + leg). Here is a diagram courtesy of LsDiodes that will clarify what I am trying to say.
If you place an LED backwards nothing bad will happen. The LEDs just won’t turn on. If you need resistor wire this into the circuit before the LEDs. Wire to your power source and a ground to finish up your circuit. Now your circuit is complete and your LEDs will work just fine. I would recommend using electrical tape or shrink tubing to put around your soldering joints to prevent a short.

PARALLEL

Now on to a parallel circuit! A parallel circuit allows you freedom when choosing how many LEDs you would like to wire. Many people wire in parallel because of this “freedom”. This kind of circuit works great if you have a small voltage source and need multiple LEDs. If you had a 5V source and wanted to wire 3 LEDs (requiring 2V to run off of) there wouldn’t be enough power to power your LEDs. That’s true with a series circuit, not so with parallel. A parallel circuit works like so: “while every LED receives the same amount of voltage, the current of the source is dispersed between the LEDs.” What this is saying is that you will draw more power from you source. When wiring to a point on the XBOX 360 this won’t be an issue, only if you were getting your power from batteries or a similar power source that couldn’t replenish itself would you possibly need to consider this.

Because parallel doesn’t have any tricks for finding out how many volts is going through each LED I am going to skip to how to wire it. When wiring in parallel you always need a resistor. When wiring in parallel you wire the + legs together and the – legs together. Here is another diagram courtesy of LsDiodes.

RESISTOR CALCULATOR

Now that you know about the various wiring methods I am going to talk about resistor calculators. In order to use a resistor calculator you need to know several things (I mentioned these above but here they are again):

A) What is the voltage of the power source?
B) How many LEDs will you be wiring?
C) What wiring method will you be using?
D) What is the voltage drop of the LED (How much power does it take to run it)?
E) What are the recommended milliamps (the desired current)?

Do you know this information? If so lets move on. I am going to be explaining everything from here on, based on this particular resistor calculator. Find on the page the wiring method that you will be using (series is in the middle and parallel is towards the bottom). Enter in the information that it asks (that would be my A,B,D,E). Double check the information that you have entered and hit “Click to Calculate”.

The information that you are looking for is this, the “Nearest higher rated 10% resistor” and also “Calculated Resistor Wattage” and “Safe pick is a resistor with power rating of”. When purchasing a resistor I look for a resistor that has an ohmage of the “Nearest higher rated resistor” and a wattage between the “Calculated Resistor Wattage” and the “Safe pick”.

That concludes my tutorial. If you have questions please feel free to ask.

Pictures from LSDiodes.com
Other reference sites used: connectors.tycoelectronics.com/glossary/glossary-r.stm
Resistor Calculator: http://metku.net/index.html?sect=view&...dcalc/index_eng

O’Malley

hahaha i love how you said a BRIEF tutorial. lol.

Anyways, awesome tut. Im sure this will help tons of people.

This deffinetly deserves to be pinned.. woot woot!!

Great turorial, and SickMod's resistor calc. is easier to use for our purposes IMO, so here ya go everyone!

http://sickmods.net/index.php?site=resistorcalc


Pin this !

@ Snow rider: The resistor calculator that you recommended is easier to use. Thanks for the link.

For people who would like a basic resistor calculator I would recommend the one mentioned by Snowrider.

Thanks for the comments everyone.

O'Malley

Dude, those are some funky ass LEDs! I love it!

they look like thse binky-things that babies suck on

nice tutorial.

I have added to the pinned thread.

nice tut. great pics from lsdiodes.

Added to Tutorial Thread under Case mods.

Thanks for adding it to the tuts area and for pinning it. Glad everyone likes it.

O'Mallley

Praise the lord!!! Maybe now I won't get pm's ever day asking"which resistor do I use in the hdd ".... Sorry to everyone that asked, but its true.

HeHe Already added. See my earlier post

Great tutorial! Thanks for taking the time to write it.

-R

Very cool looking indead, im going to attempt to try it myself but i don't know much about this type of thing, it shouldn't be to tough to figure out, but i need the LED lights, what type is used here and where should i get them from? i did a quick search on the net and found 3mm blue led lights (quantity of 6) for 11.10. can you help me out with the lights?

Great job. Good for the people who need it.

Picture links fixed.

What if I cant find the right resistor what is the amount that you can give and take because this will be my first time using a resistor and I don't want to screw up to bad but I know I will.

The tolerance for LED's is pretty good but always go for the higher resistance value when you have the choice (to be safe).

Not on the tutorial is a quick word on how you can make values with common resistors.

ie - make a 470 Ohm resistor by putting 2 x 1K resistors in parallel for example. (=500 Ohm), make a 47 Ohm resistor by putting 2 x 100 Ohm resistors in parallel - you get the idea.

Also on the power rating side - a number of resistors in parallel or series will multiply the power factor. eg

2 x 100 Ohm 1/4 Watt resistors in parallel is the equilivant to 1 x 50 Ohm 1/2 Watt resistor. 2 x 47 Ohm 1/4 Watt resistors in series is the equilivant to 1 x 100 Ohm 1/2 Watt resistor.

Thanks for this tutorial! Saved my but!

But I'm still wondering? Where do you get the power source in a Xbox 1, and Xbox 360? I can recall people talking about the HDD power cable and each wire is a certain amount of volts? Where will I find this? And How would you get the power from the cable? Would I just strip a part of it and connect and solder a wire to it to split the wire?

Thanks

Bvlaar

I'm looking for the power source in the 360 as well

I wanna light the vents to start.

First off I want to thank the person that wrote this tutorial. Second I have a few questions to clear the fog that is rotting my brain on my simplistic project

I have a simular setup that i am trying to wire in PARALLEL.

What I have:

5 green 3.2Vf-20mA 10 Candella LED's
5 330 ohms resisters
9 volt battery
switch (on off)
a board to wire them on
new soldering gun

I have used different calculators to confirm my setup to make sure it was right. one of the places i used was the awesome calculator found on led.linear1.org site.

pictures of what i have so far:

pic one
pic two

Now i am not sure about some of this so i stopped at where i learned somewhere I had to make all the negative on one wire, so as you can see, i joined them all together on one side to use it as the negative side. After looking at the graphic on this tutorial, when i setup the wires the resisters got really hot.

if I hook up the positive wire on the led to the positive on the battery then touch one of those open ends i have there, it works. Im just really confused how to wire this correctly. all i want to do is hook all 5 up so i can turn them off an on.

I would appreciate *any* help.
Thank you

huttman

You have it right, and you're using a common Cathode setup (all the LED grounds tied together, thru the Resistors of course) so it's bass ackwards form the diagram but makes NO difference and works just the same. Just wire all of the LEDs Anodes together and run them to your 9v + side of the battery, then run each of the 5 Cathode leads from the LEDs to each Resistor lead sticking out there.

thank you very much for the quick reply. I wasnt sure about having all those wires connected in one big connection. do you have any suggestions on what would be a clean way to have all those anodes together?

again thank you very much.

Do the same thing ya did with the Resistors, unless you're mounting them somewhere else, then ya still just do the same thing. Ya shouldn't have the iron on the lead for more than a second or so to make the solder joint, if ya do you're not doing it right.

ok, ill post a pic once i have completed it. most likely tomorrow.
thanks again

Ok so to wire them in you need to wire all the + legs together and all the - legs together and then wire them to the + and - on the power supply but how do you do that when you wire them into the 360 power points on the motherboard? THere is no + and -, just 5v/12v power supply points.

3.3v, 5v, and 12v ARE your "+" points.

Then you have your "-" points.. which are often noted in pictures/diagrams by a "black" dot or line or something similar.

As sicknasty413 pointed out 5v and 12v are the + for your LEDs, but don't use any 3.3v spots for driving them.

You also do NOT want to wire all of them together first and then to your power source. It depends on how many you have and what voltage source you're going to be using as to how they should be wired. 1 Resistor per LED and driven from the 12v source is recommended, if you paralleled them all up you'd need a pretty high Watt Resistor, depending on how many there are, but if it's 2 or more a 1/4w will not cut it. If all the LEDs are the same color and you use the 5v source you can parallel 4 or 5 of them up and still use a 1/4w Resistor.

I don't mind if I use a 5v or a 12v source, I was going to use the 12v but someone in another thread said 5v was better.

I have 12 x 12000mcd red LED's I want to wire in. I was going to wire in series but the resistor calculators say I can't do that so I need to wire in parrallel which is why I was getting confused with the + and - points on the motherboard.

So to wire these in parrallel I would need 12 x 15ohm 2watt resistors for a 5v supply or 12 x 47ohm 4watt resistors for a 12v supply?

And I wire them like this:

Power supply ---> Resistor ---> Led ---> Resistor ---> Led and so on....

Would this work?
GREEN = RESISTOR
BLUE = LED


RDC, to get the resistor I would need for each LED, I would just plug in "1" as the number of LED's I am using in the resistor calculator since the the voltage going through each resistor will only be powering 1 LED?

That'll work just fine.

And yes, you put "1" in the resistor calculator.. since you're only finding the proper resistance for 1 LED.

is there an advantage of using the formation i drew above over one resistor for all of the LEDs?

I have a quick question. Can I cut the length of the wires on the LEDs and resistors?

Yes, of course you can

You just solder up everything the way you want then when your finished cut off the remaining part of the leg

Awesome tutorial. Very solid.

I usually just use a hand calculator.. but here is a online one I found a while ago. Even draws you a diagram for a series or parallel cct.

http://ledcalc.com/

Enjoy.

Hi everybody, i have just dicide to install some leds in my xbox360 system, but i dont dont know where can i install them inside de xbox360. Please can you tell me where i have to wire leds inside the xbox?

REGARDS

Ok I am a little confused and want to make sure I understand this before I attempt it....

If I wanted to wire up say a rough number of 12 leds.

so I buy 12 blue leds.

My power supply will be the 12v.

Now do I need to buy a resistor for every led? so 12 resistors or just 1 resistor?

for instance the radio shack near me has this...

Blue led 5mm

* Size: T-1-3/4 or 5mm
* Typical voltage: 5.0, with a maximum voltage of 6.0V
* Typical wavelength: 430mm
* Typical MCD: 300
* Viewing angle: 24°
* 30mA (max)
* Sold in package of 1


do I need to get more information before I plan this out?


Also to the pro's who have done this before what do you "put" these on. do you let them "lay" or do you mount them to the case itself some how?

see my problem is, I have no clue what my LEDs voltage is now, and I don't think it's printed on them. I just wired two blue LEDs to 2 AA batteries in paralell and both aren't very bright at all. I am thinking it's not enough power, so I was going to use 9v battery case. I think they are 3v each, so that would explain the dimmness(they are blue)

Also, how do you determine miliamps? Would that just be something known when purchasing??

I wired up 4 cold cathodes together to a 12v wall jack, and while they all light up pretty well, for some reason I expected them to be brighter.

This is somthing Ive been stuck on for a while now. I want to take ten of these http://www.frozencpu.com/products/1879/ele...ml?tl=g6c77s117 an solder them to a 12v source but the idea of resistors and where to put them and how many I need and how to wire this all together gets me confused as hell. Cathodes are so much simpler, but the lighting effect of leds are so much better. Could some one help me with this? Also I havent really looked around to much on the jasper board but I was wondering if the 12v areas are identicle to the older boards?

This wiring job would work right? But what should I use to make sure the + and - don't touch? Masking tape? And where can I most conveniently put them, along with running the wires. Thanks!

Sending 12V through that is going to give you a quick and stinky light show. That's if the resistor doesn't burn up first.
How many LED's are you aiming for?
This is what I did for mine


If you give the V size and the current needed for the LED's desired (most are 3V 25ma) and how many you want I could figure it out....well better yet, you should and get a quick schem up for checking. Much better to make you suffer through it so you can feel the pain of learning lol

6 blue 3mm leds, Forward Voltage : 3.2~3.6, Forward Current (mA):20. I threw in the info on a calculator and said I could use a 82 ohm resistor, but even still that's too much voltage? Should I not use a parallel circuit for lighting up the inside of a 360? Led circuiting is not my forte .

Solution 0: 3 x 2 array uses 6 LEDs exactly
The wizard says: In solution 0:
* each 120 ohm resistor dissipates 48 mW
* the wizard says the color code for 120 is brown red brown
* the wizard thinks 1/4W resistors are fine for your application Help
* together, all resistors dissipate 96 mW
* together, the diodes dissipate 396 mW
* total power dissipated by the array is 492 mW
* the array draws current of 40 mA from the source.
Basically you will want a series-parallel circuit.



Take my circuit above and do yours identical only minus 2 branches. and the two resistors you use will be 120 ohm.
Did the calc for 3.3V across each LED. not running it at max V will give an indefinite lifetime. Well at least a lot longer than the 360 will
also, as long as you snip the legs to about half a CM and solder your wire to the legs then, there is almost no worry about shorting. And I used a hot glue gun for stamping my LED's in place. other wise electrical tape is fine...
ANY other questions or if you want a schem drawn, or more explanation of anything, I LOVE playing with LED's so as long as I can, I'll try and get ya some kind of decent explanation
good luck!


Oh, and yes the resistor wouldn't work with that. To run like that it would need to be more like a 350 ohm resistor rated at like 4W....very impractical
You were pretty close on the wiring, just needed two branches of 3 LEDs...It's also better to put a resistor on each branch to spread the current put on them

How's that? On your schem though, you have a switch on the top left. Is it not necessary or do you recommend that? Thanks for the help.

Perfect man!!
No, the switch I put in is purely for myself. Sometimes if I'm playing or downloading something and it's a bit bright, I like to have the option to shut them off. Same with the pot doing the dimmer switch.
Yours will be perfect like that, just will be on all the time the box is.
Nice work

Thanks! After giving a few radioshack's a call, none of them carried that resistor. So I'm ordering it off of ebay, but what does it mean by 1/4 watt or 1 watt? Their both 120 ohm, but what's the difference? And which one should I get?

Size is the only difference. It's how much power they can dissipate and you'll be plenty fine with a 1/4 watt. In fact if you didn't buy them off ebay and you give me your address, As long as you live in US I can send you some....I bought a pack of about 5 thousand various sized resistors. Unless you wanted to buy a big pack like that go ahead

And if you want to put 10 leds in total , which restistor should i use ? in Ohm, (i know i made a mistake on pic i typed mA)

Well, to me that's not a mistake. I always write mine like mA. M is for mega, so you're spot on!!
And I need to know what color LED, Voltage rating, and mA rating. At the very least a color rating and the rest can be generalized.
And the 12V is going to spread diff on yours. you'll need more branches. And for convenience you'd be better off with 9 LEDs or 12. Multiple's of 3 is best for LEDs at 12V