Introduction: Modular Magmount LED Lighting

Picture of Modular Magmount LED Lighting

Christmas light bulbs are incandescent and burn out at an ever increasing rate. This was fast enough that my roommates and I got blisters from pulling them. I had those lights up for over two years and I wasn't about to go without ambient lighting. I figured LEDs were the way to go.

Each module is powered by 12V and is relatively simple in concept. The number of LEDs you need per module depends on the voltage of the LED. You'll typically be able to get 3 blues or greens (3.4V each) on a module or 5 reds (2.4V each) on a module. A VERY large number of modules can be powered off of one supply. The maximum number of modules that can be powered by a single supply can handle is its amperage divided by the current a single LED pulls. In my case, I used a 12V 5A power supply from Digium and 20mA LEDs, so that gave me 250 (5/0.02) modules per supply. That's a whole lot of light!

Parts for each module:
A piece of breadboard
3 blue LEDs (3.4V)
A 100 ohm resistor
2 small neodymium magnets
2 ferromagnetic thumbtacks

Other materials:
Soldering Iron
Hot Glue Gun
Glue Sticks
Speaker Wire
A 12V Power Supply

Step 1: Materials and Organization

Picture of Materials and Organization

Your first task is to gather your materials and find the module configuration that suits you. For each module, you'll need some perfboard (the really cheap stuff if possible), a 100 ohm resistor, three 3.4V blue LEDs, two 1/8"x1/8" neodymium magnets, and two ferromagnetic thumbtacks. For general supplies, you're going to need a 12V power supply, some cheap speaker wire, a soldering iron, some solder (lead/tin), a hot glue gun, and some glue sticks to go with it. A third hand pcb holder is helpful, but not required. As for organization on the perfboard, it's really up to you, but I chose long and skinny so my modules would have a similar profile to the wire itself and be less obtrusive.

Once you have decided where the LEDs go, make sure that they are in the correct orientation. The longer lead is positive and goes away from the resistor. The resistor will be the link to the ground for the module. I left a gap between the perfboard and the LEDs so that I could bend them and better distribute the light. Bend the leads that are going to connect toward each other so that they lay parallel and almost touch. The end result of this is shown in the next step.

Step 2: Soldering and Coils

Picture of Soldering and Coils

Now that you have your LED and resistor leads bent to the proper positions, you'll need to solder them together and clip off the excess part of each lead. Take care NOT to cut the outer leads as you'll need them in a minute. Try to use the minimum amount of solder that is necessary.

Take one of the magnets and bend an outer lead around it, creating a spring or coil-like structure. This will help hold the magnet in place and maintain conductivity. Once you have both ends coiled properly, insert the magnets and make sure they still fit. It is fairly easy to mess this up, so you may have to practice it a little.

You must be VERY careful on this step or you will ruin the magnet. Even relatively short term exposure to high temperatures can cause the magnet to lose its magnetism. Since the resistor lead isn't magnetic, I would suggest using a tiny bit of solder to connect it to the magnet. You want this to be a cold solder joint, not a hot solder joint.

Step 3: Hot Glue and Thumbtacks

Picture of Hot Glue and Thumbtacks

Since everything is soldered now, you only have a little further to go until your LED module is functional. Take the hot glue gun and glue the magnets down on their sides. There isn't much need to worry about killing the magnets here since the glue gun doesn't transfer nearly as much heat to them as the soldering iron. Wait for the glue to harden before attempting the next part.

Once the glue has hardened, take the module, set it next to the speaker wire, and mark the wire where the center of each magnet would come in contact with it. This is where you'll need to insert the thumbtacks on the wire. Make sure they pierce the conductor inside the wire. This isn't easy to mess up, but if you're paranoid, you can check with a multimeter to ensure conductivity. Make sure that each pair of tacks doesn't go into the same conductor. This is how the modules are powered, and if both tacks go into the same conductor, that module won't work.

When you have the spacing right, you can use the thumbtacks you just put in as a template for the rest of the wire and since they have such a large surface, there's plenty of room for error. Another plus is that there is no need to have nails in the wall for it. Just hammer the tips of the tacks into the wall!

Now that you have your thumbtacks in your wire, connect the 12V supply and attach the module to a pair of tacks. If it doesn't work, try turning the module around. Reverse polarity won't hurt it. If it still doesn't work, make sure your connections are good between LEDs and specifically, between the resistor and its magnet.

Shown is a closeup of a working module and my hallway in near daylight. If you want to make a red module instead of a green or blue, substitute the three blue or green LEDs for 5 red ones and the 100 ohm resistor for a 1 ohm resistor.

Step 4: The Final Product

Picture of The Final Product

Here is a night view of the final product of this project. This, in addition to the kitchen half of the lighting, only pulls 1.26A of current. This means my power supply is only at 1/4 capacity! I could easily double the number of modules and cover the rest of my apartment, not to mention the possibility of ice sickle style modules. The real beauty of this comes into play if a module ever burns out. There's no way it can affect the remaining modules and you can just pull it off the wire to fix it. Burnouts happen at a very linear rate, where the Christmas lights burned out at an exponential rate. I haven't had one burn out on me yet.

Surprisingly enough, this project only took about 12-15 man hours to complete including all the LED module and rigging the speaker wire with thumbtacks. With help from my friends, we got all the leads coiled, magnets glued, and wire pierced in a couple hours. The cost was a little high, but I'd say $100 is a great price for lighting you won't have to replace for a decade or so.


maxwelltub (author)2010-01-18

awesome, i love it

ledlightmaker (author)2009-12-23

 I love your idea and design.
Lights along with wall, i suggest a side emitting lights,wich give most lights upwards.

InfinityChic36 (author)2008-08-12

That turned out really nice!
Another thought for your power supply problem? Who *doesn't* have old power adapters laying around from old cellphones or the like? Just cut off the jack and strip the ends a little bit. *Carefully* check with a multimeter which is power and which is ground (and also how much voltage you are *really* getting out of it). The plug that goes into the wall should tell you it's output - a laptop converter is usually around 16V, cell phones around 5V, old baby swing adapters around 9V. That let's you off without having to come up with a step-down transformer.

You can get screw terminals that should plug into your breadboard and provide a nice safe insulator for the power leads if you want a solder-free project.
You can even cut the power cable within your arm's reach a stick a switch in parallel to control colour, or just on/off.
(I just did this for a lamp with a regular light, manual colour changing via a toggle switch, and a triangle wave generator that automatically fades in one colour, then fades out and fades in the next colour... it turned out really nice)

opticron (author)InfinityChic362008-08-12

That sounds pretty cool! Do you have any pics (or video) of the lamp?

InfinityChic36 (author)opticron2008-08-12

I gave the lamp to my friend, (she had one of those paper lantern things). I duplicated it for my fishtank, though. Check back in about a week, after I get it set up (I'm moving this weekend)

xdayz (author)2008-05-24

this is great! and even greater if powered by solar energy!

dondangler (author)2008-05-13

Just an idea, but you can eliminate the soldering the magnet by soldering thumb tacks on the bread board as well as using them to pierce your power cable. just use the magnets on stick the thumb tacks together

Fast Eddie (author)2008-02-14

Very cool. I want to try this, and have everything pretty much figured out but a few questions:
1- Could you explain your "12V 5A power supply from Digium"? What exactly is that? I imagine its something you plug into the wall and converts 120V IN / 12V OUT? * doesnt seem to have my answer *

2- Also would it be wise to try this without the magnets? Just wrap the leads around the tacks and insert into the wire? I Dont want to burn the house down :)


Big Bwana (author)Fast Eddie2008-04-23

Any 12 power supply would work l, like A PC power supply or a walwart even a coleman cooler power supply... No magnets you can solder to tacks ...

opticron (author)Fast Eddie2008-02-14

The power supply I use originally came from a Digium AA50 telephony appliance. Since I work there, I can get them at cost and they're great, because they can put out a whopping 5 Amperes. Any 12V power supply will do, though. As for your second question, the reason I used magnets is so that I can rearrange the modules whenever I want. You could just as easily skip the magnets and wrap around the tacks, but after taking them off a couple of times, your leads are going to break off from metal fatigue.

invinciblewhale (author)2008-03-17

Hi! LOVE the idea! I don't know very much about circuitry or electronics, but I'm trying to do kind of the same thing as these Modular Magmounts - probably not as complicated though, I just don't know much about doing this kind of thing... I was wondering if anyone can help me? Actually for my project, I'm just trying to make an LED string of lights that are different colors. This is to light up a bunch of dioramas in a gallery. I don't actually need any magnets or anything... Anyway I was wondering if it's possible to do that since a lot of the LEDs are different voltages and mcds? And what is the purpose of having the modules on the magmounts? Is it because they're easier to put up together? Or do all the LEDs in the module share the same resistor - and you only have to calculate how much resistance they need for the three of them combined? Can I calculate each LED's resistance needed for every single LED and just give each LED a resistor separately? I am probably going to use about 20 LEDs total. I have a 12v transformer... and I'm afraid of messing up! Should I be using speaker wire too, instead of regular thin wire? Thanks everyone! Sorry for being such a n00by -_-

opticron (author)invinciblewhale2008-03-18

It's definitely possible to have single LEDs with the 12V supply, but that means that your resistor is going to have to dissipate quite a bit of energy as heat. You'll also need a different resistor for each voltage of LED. I used magmounts so I can rearrange the modules as needed. The LEDs on a module also share a resistor, so I didn't have to buy as many. Speaker wire was just convenient for me. Any wire that is capable of carrying sufficient current for the LEDs should work fine.

pencilshavingsuk (author)2008-02-28

Hey, sorry to sound abit n00bish but what do you do with both ends of the speaker cable? Do you simply connect one end or both to the 12V supply? Just wanted to check as well before i put it all together. Another quick q ... Can you use any bog standard thumbtacks? If not where abouts can i get the ferromagnetic thumbtacks in the UK?

You connect one end of the speaker cable to the power supply. The other end is left totally unconnected. As for the thumbtacks, ferromagnetic just means that a magnet will attach to them. Most should work for this purpose.

mintyhippo90 (author)2008-02-16

instead of soldering / hot gluing the magnets in place you could play it safe and just use conductive epoxy

opticron (author)mintyhippo902008-02-20

Do you know of a good place to acquire said conductive epoxy? I looked around a little and don't see a lot of options. Any you recommend specifically?

mintyhippo90 (author)opticron2008-02-21

i think they might have it in the aisle of various adhesives at home depot, but im not sure. Ive never used the stuff myself, it just sounded like a much easier alternative to the haphazard solder / hotglue method you described. you may just have to check around the internet for some..

btw, i am in love with the whole concept. youre use of the thumbtacks and magnets is inspirational. hopefully my contribution can make youre fantastic idea even better.

opticron (author)2008-02-20

I'm going to do an update to this sometime within the next few weeks (when I can get parts in) taking several of the really good suggestions to heart. Conductive epoxy is going to save me a ton of headaches with soldering to the magnets and wrapping the LED and resistor leads around them. Hopefully a better design will come out of it for the room party at Outerz0ne 4 that my friends and I typically have. I may do sanded lenses for better diffusion as well.

Brian Henderson (author)2008-02-20

Clever! I really like the thumbtack + speaker wire + magnet setup.

Big G (author)2008-02-11

Nice! I'll have to say that thing with the thumbtacks is one of the most creative ways ever of getting power to LED's. :-) You could probably employ this method to do some under-cabinet lighting too, with some white LED's, or even put the LED's in the soffit on top of the cabinet (if yours has one) for a more "ambient light" look, without having to look directly at the LED. That would look pretty cool! But overall, great instructable! (clicks on the +rate button) :-)

jfc443 (author)Big G2008-02-11

sorry if sound bit dumb bout this, but hey im only a teenager lol and it myt help. but yer anywayz i hooked up some colour changing LED's to my stereo system and you need to crank it up quite abit to get a decent pulse, but hey lower voltage LED's myt work a treat, let me know if you try would love some feedback on this idea.

opticron (author)jfc4432008-02-11

That sounds cool. Did you have to dedicate an output channel to it or did you leave the speaker hooked up too?

jfc443 (author)opticron2008-02-12

I tried both and they were both effective, I also tried hooking them up to where the speakers were plugged in, just to test it out but the speakers drained it to much. but I think its best to dedicate them to another output channel for a better quality of sound.

WilderLust (author)jfc4432008-02-17

be careful! you need to make sure your impedances match. stereos are setup to have 4 or 8 ohm loads for speakers. there are many different types of stereos with various levels of toughness but the amp circuit can eventually fry on you if you get too far out of its specs. you can make music light drivers with a few opamps and isolate the device from the stereo to be safe. and by the way... i started electronics before i was a teenager so "just a teenager" is the perfect time to get into electronics :-) cheers, WL

jfc443 (author)WilderLust2008-02-18

okies thanks for the advice, will bare that in mind.

and about the 'just the teenager' bit... I've been into electronics since I was little and im nearly 16 now lol, I just thought I would cover my ass as i know there's alot more experienced people out there =p.


The Expert Noob (author)2008-02-14

oOo!!! Im so bookmarking this instructable. My Idea will involve the RGB LEDs. I would have to find some 4 conductor wire, but 4 magnets per module might get expensive, so I may use a 4 conducter, crimp on computer connector to quick connect the modules. I will use a microcontroller w/ PWM (color changing) and trasistors (for amp load) to create 256R x 256G x 256B to create 16777216 colors. All LEDs are not created equal tho. so I may step it down to 16x16x16 colors, but you get the concept.

just what I was thinking! put some RJ11's on both ends of the module and you good to go! i know asm for pic but have never played with PWM so hit me!

This is for the <a rel="nofollow" href="">ATMega8</a> PWM RBB LED Controller<br/><br/>also this is what I am going to base mine off of<br/><a rel="nofollow" href="">PIC12F675 Single RGB LED Controller</a><br/><br/>You can also control it via the serial port on a computer using the persistence of vision and turning on the LEDs one by one (of RGB) and deciding the intensity by just one byte at a time! A simple program can be written in basic joined with a chip that sends each byte (1,2,3,1,2,3 aka R,G,B,R,G,B) for each byte it receives.<br/>

Less use to chaps overseas but a decent magnet supplier in the UK.

I'm not affiliated with them, but they've served me well in the past.

GitarGr8 (author)2008-02-15

Cool idea! My only suggestion would be that you use a light diffuser so that you don't get the ring of light pattern. Simply sanding the LED does wonders for this.

waterppk (author)2008-02-14

Very cool. I had lighting like this in my house last year because my stupid room mates would leave the lights on constantly so I put LED lights everywhere so they would have no reason to turn the lights on when they walked through at night. The thumb tack idea is genius though :) If you live near a harborfreight store you can get the 2 wires speaker stuff really really cheap, you can order LED's from All for cheap too :)

trixcomp (author)waterppk2008-02-14

Hey! your room mate was stupid aye! that hurts bro... but not as much as stubbing my toes because I could see what i was doing under the red led light :-).

GorillazMiko (author)2008-02-12

Wow! That's really cool! I would like to do this to my room, that would be sooooo cool. +1 rating.

opticron (author)2008-02-11

Thanks! I plan on expanding this later to include the bathroom in green and probably the other half of the kitchen. We had christmas lights up for over two years, so we got used to staring at bulbs. The white lights under the cabinet might be a next step as well now that you mention it!

Big G (author)opticron2008-02-11

Thanks! I work at a lighting store, so the under-cab light was one of the first things that came to mind. :-)

That, or a sweet home stereo dance room with a whole bunch of these, with a sound activated switch so they pulse to the that would be cool. But probably wicked expensive...

Oh, and congrats on getting featured!

Big G (author)Big G2008-02-11

Sorry for the double post, but something just struck me, in reference to my aforementioned stereo system. Since you use speaker wire anyway for the power, if you hooked up the wire to a speaker, then put the LED's on the speaker line, theoretically, the LED's would pulse to the music, because the "sound" going through the speaker wire is really pulses of could even hook the LED's up to the subwoofer line and have just the low notes pulse..... Maybe I'm completely mistaken, but that would be cool if it worked. Just a passing thought. :-)

opticron (author)Big G2008-02-11

Actually, I had considered that. What I still don't know about the stereo system is what voltage it outputs and how much amperage it can supply. Additionally, the speaker is a purely inductive load while the LEDs are almost purely resistive in nature because of the resistors limiting the current. This might mean that the amp wouldn't be tuned properly to drive them. A better solution would be a microprocessor converting voltages to PWM signals that are sent to a transistor. I've looked on digikey for this very purpose and it seems that transistors of this capacity aren't that expensive. What remains is the proper ADC and conversion to PWM which I can program on a cheap ATMEGA16. I'm sure it would be great for parties.

opticron (author)2008-02-11

I'd like to give some credit to themostbob specifically as he inspired the method of mounting.

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