Introduction: Beginners Wiring Projects: LED Banks

Picture of Beginners Wiring Projects: LED Banks

Learn to wire up two sequences of three LEDs to a PC board, mount to a project box (Altiods tin), and control them with the use of a power and variable switch.

Please note that this is a beginner project, and that I am just learning to solder and wire myself.

The wiring here is fairly simple, but it takes some thinking to figure out, especially without an equally confusing diagram...

It's amazing how much I'm getting flamed for such a simple project. I fully acknowledge that it was possible for me to use a bigger battery with a resistor, however I did not have a resistor with the appropriate ohm value at the time for any of the batteries I had present. Not to mention this is a beginner project, and the button cells work fine, even with a sequence of three LEDs. To go even farther, the maximum voltage for the green LEDs is exactly 3v. A 1ohm resistor would be useless here. The maximum voltage for the yellow is slightly less than 3v, but enough that they've been left on for more than a couple days combined, and are doing just fine.

Step 1: Materials

Picture of Materials

The materials required for this project are fairly basic, and most can be bought/obtained from RadioShack and your local hardware store.

Needlenose Pliers
Soldering Iron
DREMEL (woo!)

Wire - Any scrap will do, just make sure you have enough, it is extremely helpful if you have two colors
PC board - I got mine at RadioShack, they're cheap
Six LEDs - Three one color, and three another. All should be low enough voltage to be powered by 3-4 volts. (two 1.5-ish button cells)
Two switches - One 1-way and another 2-way
Two 1.5V Button cell batteries - Power
Electrical Tape
Multimeter - Optional, helps test connections

Step 2: Preparing the PC Board

Picture of Preparing the PC Board

In this step we will be using the PC board, solder, soldering iron, LEDs, and needlenose pliers.

My PC board I got from RadioShack Had this nice little travel circuit that I used to wire one set of my LEDs, while on the other, I manually hooked up the LEDs with wire.

Place one color of the LEDs like you see in the first picture, making sure that you keep the positive (longer) side of the LEDs to one side.

The last LED shown in the sequence is wrong in these pictures, it should be soldered like the others, exactly the same.

Once you have the three LEDs wired in sequence, simply solder a red wire to the positive side, and a green one to the negative. Snip the excess leads on the installed LEDs and start working on the other three, soldering wires to each of the LED leads instead of using the built-in travel circuit.

Simply solder the connection wires to the ends of the LED leads, and secure to the board with bent pieces of solder.

Remember, when soldering, safety is always important.

Step 3: Preparing the Project Box

Picture of Preparing the Project Box

In this step, we will use an Altiods tin, Dremel, switches, and some tape.

Take a Sharpie, or any type of marker, and mark out approximately where your holes will go. Attach a drill bit to your Dremel, and punch through for the six LEDs. Widen the holes, sometimes considerably, depending on how far off your original estimate was.

The PC board I used fits in the Altiods tin perfectly, and it sort of holds itself in place for you.

Next, repeat the process on the holes for the two switches. These need to be bigger than the LED holes.

Take off the nuts included with the switches, and mount both in the tin.

Now prepare for the wiring, here's where it gets messy!

Step 4: The Wiring

Picture of The Wiring

The wiring for this project is pretty simple, but requires knowledge of soldering. The first step will be to solder the two positive leads of the LEDs (marked by the red wires coming out of the PC board) together.

The next step will be to secure wire to your two button cell batteries with electrical tape. DO NOT SOLDER THESE BATTERIES, THEY EXPLODE! Next solder the two negative leads of the LEDs from the board to the two sides of the 3-way switch.

After that, solder the Positive lead of the battery to the power switch, and the negative lead to the middle of the 3-way switch to complete the circuit!

Good luck lighting up dark places!


uotsey (author)2010-01-02

 I have never done any type of wiring. I have a classroom project based on the nervous system. I would like to make something along the lines of the game "Operation" which tracks the path of the nervous system. Can anyone point me in the correct direction? Thank you!

shostakovich (author)2009-08-22


pyro man (author)2008-12-01

wats the dremel for? can i just use 1 3-vlt battery?

BlackHatCracker (author)pyro man2009-03-28

Yes since each LED is only rated at 1.2v

Handsome-Ryan (author)2007-10-30

What does the resistor you soldered in line with the LED's do? Oh wait, you didn't use resistors. lol.

Well it is self explaining... It lowers the voltage going to said component. Ohms law... R=E/I to find the value of the resistor needed in any project that you are needing.

That black kid you're molesting in your picture looks scared. LOLROFLMAOBBQ

cupnoodles2 (author)2009-02-06

just for the next time u coul use the leads of the leds instead of using wire good ible btw

miqt (author)2008-09-19

hey, thanks for the easy to follow instructable, i appreciate it...the pictures were pretty clear, i have 1 question though, is it possible to hook up 3 led's in the same way you did except without a pc board (just wires soldered onto the leds)? oh and if anyone else knows, i would appreciate an answer...from anyone.

Gjdj3 (author)miqt2008-11-26

Yeah, the pcb just makes it more organized. I normally don't use PCB myself.

Gjdj3 (author)2008-07-07

That's really cool, but I think you used a bit too much PC board. It could have easily been done with less. But otherwise, great job! That looks like a good way to learn. 5/5 stars.

Firebert010 (author)2008-03-23

Please provide some sort of explanation as to why that link was posted here... I understand the relevance to LEDs, but it was unnecessary.

HillBilly Homer (author)2008-02-11 no longer sells LEDs. This part of the site remains only so that people can look up product specifications. You will not be able to purchase anything. very nice project and Instructable

Thanks. I haven't bought from them in a while anyway, I prefer BestHongKong.

timberman (author)2008-01-20

i need help, want to make a sign with 50 maby 60 led's where can i go? i am a total beginner at this. bty your project was very helpful.

Firebert010 (author)timberman2008-01-21

Well, if you're a beginner with LEDs, I don't suggest starting a project that uses 50 LEDs. Chances are you'll have 20 or so soldered in to your board, and you'll fry one and there'll be this unlit LED right in the middle of your board. I suggest building a couple smaller projects such as this one first so you can get the feel for soldering these. If you do wish to continue regardless, two websites I use are and You can buy bulk LEDs there for pretty cheap.

Darkshot (author)2007-10-10

cool man i luv the idea and totally wanna do this project but two q's 1) why the PC board? 2) why a 1 way switch then a 2 way switch? get back ASAP please

Firebert010 (author)Darkshot2007-10-11

1) why the PC board?
Why not? Easier mounting.

2) why a one way switch then a 2 way switch?
I'm not quite sure what you mean here, but the one-way switch controls the power supply, (on/off switch) and the two-way switch controls which color LEDs you want to light up.

Using two two-way switches would be pointless, because half of one of them wouldn't be used at all. I can't use two one-way switches because I wouldn't be able to switch power between the LED banks, which was my goal.

Darkshot (author)Firebert0102007-10-11

mispelling is because im typing w/ 1 arm...others in a cast....long LONGG story

Darkshot (author)Firebert0102007-10-11

ohhh i get the switches now you wanted to control one bank at a time right? but the PC board still sounds pointkless to me sorry if u think im geting on youur ass too much about the PC board :/

theatre_tech_guru (author)2007-10-05

this Instructable is really good I liked it i am going to try it soon

Thank you, I appreciate your comment.

acaz93 (author)2007-09-13

Excuse me , But I Think It's Multimeter and not Potentiometer

But Good Instructable , Easy To follow , Great Beginners Project

Firebert010 (author)acaz932007-09-13

Hehe, sorry. I'm a noob when it comes to terms.

acaz93 (author)Firebert0102007-09-21

hehe , no worry ;D

rc jedi (author)2007-09-15

I never get tired of led's. Their color is frequency specific. A pure color like one would see in neon lights. They make no heat and are energy efficient.They have long life, cheap and fast switching. aaaaaahhhh................................led's ':)

Patrick Pending (author)2007-09-13

Fireberto, you should have a current limiting resistor for each of your LED's.
A standard LED would (typically) have a maximum forward voltage of 2.5V applying a greater voltage will cause damage to them.
The two button cells are not really up to the job of powering 6 LEDs in parallel.


Pat. Pending

The batteries are actually powering a maximum of three LEDs at any given time. Resistors are not required here. Ever make LED throwies? Two 1.5V button cells to a LED, no resistor.

The button cells you are using (alkaline or silver oxide) have a very low capacity (some are as low as 20mAh). The current drawn by a standard LED would typically be 10 - 20 mA. Three LEDs in parallel would require between 30 and 60 mA. You can see from the figures that the button cells wont last long!

Throwies are generally made with a single LED and a Lithium cell. These cells have much higher capacities than the ones you are using (e.g.,CR2032 > 200mAh).

Yes you can get away with not using a current limiting resistor in this case because the button cells are so underpowered for this application. The excess voltage is dropped across the internal resistance of the button cells.

Having a large tin and using tiny button cells just doesn't make sense. My advice would be to use two AA cells and series resistors of the appropriate size.


Pat. Pending

So I had a bunch of button cells lying around. I know from experience that I can light up a single LED for over a week with two of the same button cells. I don't plan on running this for more than a minute or two max, so I don't see why prolonging my battery life is such a big issue. YES two AA batteries would work fine. YES I can fit them in the tin. YES they would require a resistor. But it would involve me going out to RadioShack and buying a pack of five resistors that I'll probably never use again. So I would appreciate it if you would kindly get off my ass about it.

Firebert010 (author)2007-09-13

Tell me about it. Some of the messy soldering was actually due to this total crap 30V soldering iron that I was using.

About This Instructable




Bio: I study engineering at Virginia Tech. Long time instructables fan.
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