Introduction: Touch Sensitive RGB LED Mood Light

Picture of Touch Sensitive RGB LED Mood Light
I always really wanted a cool LED Mood Light, but all of them I have seen on Instructables use IC's, and I find IC's take out some of the fun of building circuits. That is the reason I designed this lamp. I also wanted to make sure all the parts were available from Radioshack, because I know there are other people, like me, that don't or can't order off the internet, which is another reason IC's are no good for some people. Radioshack doesn't carry a great selection.

*As well, as a bonus, since this is power by 5-6v dc it can be USB powered, but I power mine from either a 6v dc 300 ma wall adapter or 4 AA batteries.*

Step 1: Parts, Tools and Materials

Picture of Parts, Tools and Materials

This isn't an overly difficult circuit, but may be a little difficult for a beginner, but with slow and careful work, anyone can build this.  If you are a bit of a beginner, the Optional Markers under tools should come in very handy, as well as the color coated wire under materials.  For markers, I find the Colors, Black, Red, Green, Blue and Orange were of greatest help.  They are good for marking were leads of parts go onto the Perfboard and allows you to figure out what configuration will work best for you.  Just make sure you remember your color code!  As well, a solderless board is also a good idea.

For tools:

- Wire strippers
- Solder and Soldering Iron
- Glue gun (For gluing long leads down so the wire doesn't bend back and fourth and 
- Dremel or Tin Snips (Anything for cutting Perf Board)
- Side cutters
- Markers (Optional)

For Parts:

- 3x 2N3906 Transistors (Or similar)
- 3x 2N3904 Transistors (Or similar)
- 3x 1000 uF 6.3+volts capacitors
- 3x 6 ohm 1/4 watt resistors (Color code, Blue, Black, Gold, Gold)
- 3x 10k ohm 1/4 watt resistors (Color code, Brown, Black, Yellow, Gold)
- 1x 330 ohm 1/2 watt resistor (Color code, Brown, Black, Brown, Gold)
- 3x 1N914 Diodes
- 3x Germanium Diodes
- 3x Red LED
- 3x Green LED
- 3x Blue LED
- Momentary Push Button Switch
- DC Barrel Jack or Battery pack
- On/Off switch (Optional)
- Ribbon Cable with Plug (Optional)
- 5-6v dc power supply.  I used 4 AA batteries.

For Materials:

- A lamp or other enclosure (Not covered yet, as I want to enter this in a Contest, will be 
  updated later)
- A shade or something to blend colors (In the video I used a Paper Funnel)
- Assortment of wire, preferably color coated

Step 2: Circuit

Picture of Circuit

The circuit diagram is provided in the picture below.

The LEDs aren't shown in the second diagram because there are two configuration you can use.  I wired them in Parallel because I believed that the voltage drop across them would make them too dim.  However, it is your choice to put them in Series or Parallel.  In Series, all the LEDs will be the same brightness but may be somewhat dim.  In Parallel, due to small differences in each LED, they may be slightly different brightnesses, but will be brighter overall then the series.  This is something to think about, the circuit should work both ways, so it is completely up to you how you wire your LEDs.

As well the LEDs are setup in this fashion:

Red Green Blue
Blue Red Green
Green Blue Red

Step 3: How It Works

Picture of How It Works

I wanted people to be able to build this circuit, but also understand its workings, if they didn't already understand it.  Anyone can build a circuit, but I wanted to make sure people knew how it worked.

This is a very simple circuit.  In the pictures you can see one piece of the circuit.  It is one controller for one color.  They all work exactly the same though.

When a finger is placed across positive and one of the three pads, it turns on the corresponding NPN transistor.  This allows power to flow to the rest of the circuit.  The ability of a capacitor in series with a resistor to increase the time it takes to charge allows the LED to come on slowly, allowing you to vary the brightness based on the length of time you leave your finger on the touch pad.  Then the very large resistor after the capacitor slows its discharge so that the lamp doesn't immediately dim.  I don't know how long it will stay lit for, I think somewhere between 5 mins and 30 mins.

To turn it off, the momentary switch is pressed for about a second which discharges the capacitors.  The Germanium Diodes are needed so that all the capacitors don't charge at the same time, which wouldn't allow you to vary each color.  The Germanium Diodes are only good for small current, but will take a substantially high Surge Current, and since the capacitors discharge immediately and no more power flows, they are acceptable for use here.

If you wanted to increase the power supply and add more LEDs, you would have to change values of certain components accordingly.

Step 4: Construction

Picture of Construction

Start with the Transistors, all of them.  Careful of which direction they go and don't get NPNs mixed up with PNPs.  Tack them on.  Next do the Resistors and 1N914 Diodes.  Next solder the positive jumpers and negative jumpers.  Next solder the 3 capacitors on.  Careful of capacitor polarity.  Finally solder the 330 ohm 1/2 watt resistor and the connections for power (2, + and -), Touch Sensors (4, R, G, B and positive),  LEDs (4, R, G, B and return to 330 ohm resistor), and for the off button (4, one off each negative lead of the capacitors and the last to positive.  The three from each capacitor need to be cut in half and add the Germanium diode, careful of polarity, into each wire before connecting all three together then to one side of the momentary switch.  The positive lead attaches to the other side of the switch.  If this is confusing look at the last picture)

For the LEDs, Figure out what configuration works best.  I found one hole between everything worked best and was easier to solder.  Tack one leg at a time.  Make sure they are all lined up the same way.  This is the hardest part because the optimum configuration has same color LEDs scattered around the board.  GO SLOW!  Use color coded jumpers on the bottom.

Step 5: Test and Enclosure

Picture of Test and Enclosure

Now that you have everything soldered, test it.  Carefully check and connect negative and positive.  Find the touch return and press one finger to it then one of the colors.  The LEDs will take a few seconds to get enough power to be visible.  Once they turn on, try all 3, then try the off button.  If it doesn't work, disconnect power, and check wiring.

If it works, Congratulations!  But your not quite done yet.  You should put it in a case.  A lamp that would be good for mounting the touch sensors and off button would work.  If you wanted, a plastic box would work if you put everything in it and ran the LEDs up on top with a CD holder (The tall clear ones)  that had some Mat White paint on the inside of it.  Anything clear doesn't work because you can see the colors individually, but by using a translucent material (I used the paper funnel) the colors blend and trick your eyes into to believing the lamp produces any color.  

I will update this part later when I have mine in a case.  Due to time constraints, I want to get this entered into a contest first, then I can add in the enclosure section after as I want to find a really nice lamp to put this in and I don't know when I will find THE PERFECT LAMP!  However, the enclosure is up to you!

If anyone makes one of these, I would love to see pictures of it, so post them in the Comment Section below!  :D


gkoutsioukis (author)2011-03-29

I am curious about how the all touching thing works.Are there switches of sorts? Or you just tap the wires with your hands to make the color switch?

Wesley666 (author)gkoutsioukis2011-03-31

The way it works is there are 3 NPN transistors, one for each color. NPN transistors work that when the voltage at the base becomes positive they turn on, and power can flow across the collector and emitter. The base voltage can be very small and it can control a large amount of power across the collector and emitter. Since you don't need a large voltage we use skin resistance to control when they are on and off. So there are 3 leads, one from the base of each transistor, and each have a small gap between it and the fourth lead, and the fourth lead goes to the positive terminal on the battery. That way when a finger is placed across the gap of one or more of the gaps it turns one or more of the transistors on. The longer a finger is held across the gap, the brighter the lights get.

gkoutsioukis (author)Wesley6662011-04-04

I see now, thanks a lot!

Plus, I could not find germanium diodes so I consulted my electronics teacher at the university and he told me to switch them with pyritium diodes. Do you think it would make any difference?

Wesley666 (author)gkoutsioukis2011-04-04

Pyritium? O_o Wow, uhhh, I use whatever I can pull for stuff at the dump and in a over-priced store with very, VERY poor selection, so I have never heard of Pyritium Diodes. I would say they should work. I used Germanium diodes because they have lower voltage drop then standard rectifying diodes (1N4001 or similar) so if Pyritium possesses the same low voltage drop quality as Germanium I would say it should work. In all honesty, even standard rectifiers like the 1N4001 should work. It might affect it, but it probably wouldn't even be noticeable *IF* it did affect it even. If your Uni Teacher suggested pyritium, then he is probably right, I am self-taught and have about 3 years experience, he probably has alot more then that. If you showed him my schematic, he could probably make alot of improvements/changes...That's kinda of a cool thought actually, getting someone with alot more experience to look at it. I would find that very educational. Sorry, I am getting off topic.

To answer your question, yes, they should work with little to no noticeable affect.

gkoutsioukis (author)Wesley6662011-04-05

I will show him :) He is so crazy that he may add a fridge or a laser gun on it as a bonus. :) Will post here his comments.

Wesley666 (author)gkoutsioukis2011-04-05

Thanks! I think this could be a good learning experience!

Also, he sounds like an...interesting...fellow. Maybe not someone you would want around said laser gun, but inertesting none the less! :P I have heard that Uni Teachers have a tendency for being kinda out there though! Haha!

Can wait for a reply! Thank you!

munymuny200 (author)2011-03-27

nice work, very great project

Wesley666 (author)2011-02-28

Looking at possible selling these as a kit, if anyone would be interested message me. Price would be set about $30 - $35, maybe $25 if I can find cheaper, but still very bright LEDs. Mind you, I don't have any yet, I just want to see if this would be worth while.


Eman012 (author)2011-01-26

does it really sense the mood of a person?

Wesley666 (author)Eman0122011-01-26

Not really, its more like a touch sensitive dimmer switch for each color and you adjust it to the color you want. Now that I think about it, this is probably more accurate then any temperature sensitive mood light, just because subconsciously a person will probably adjust the light to a color that they at that moment will enjoy and this is probably affected by emotion, so it can be argued to be a mood lamp. But it doesn't matter too much, I called it a mood lamp cause you can make any variety of colors (Except black, grey or brown) which is all a mood lamp does...

Eman012 (author)Wesley6662011-01-27

How can I make the LED react to music? Can you help me?

Wesley666 (author)Eman0122011-01-27

So, you want to be able to adjust the colors and get them to react to music, correct? Or do you want the music to adjust the colors? Or do you want it to do something else I am over looking? Reply, and give me a day to think about it...I kinda have an idea already for adjusting the colors with the touch pads and having them flicker to music, but I would like to test it on a bread board, because if I find something that works well, I might want to do it too! Plus then you would know what your building will work. :D I have to say, good idea! I never even thought of adding audio to this!

Eman012 (author)Wesley6662011-01-28

I want the music to change when the color changes too. Can you help me?

Eman012 (author)Eman0122011-01-28

And what material did you used as the touch pad? How are they connected?

Wesley666 (author)Eman0122011-01-28

The touch pads are made of anything conductive, I am using copper clad for them. No, they don't touch, you want them to be close so you can touch 2 of them at least (the return one and one color) at the same time for this to work. There are never too many questions if you don't understand something.

Eman012 (author)Wesley6662011-02-16

Hey! Sorry if I replied late.. I'm still having problems. I don't know how to make the music react on the LED. Can I make the color change when I change the music? For example, when I play the song "Grenade", the color of the lamp is red, and when I change the music to "Tik Tok" , the color will change into blue. I really need your help. I need it for our Science Fair. :| Please reply ASAP. Thank You. :)

Eman012 (author)Eman0122011-02-16

And what's dc barrel jack look like?

Wesley666 (author)Eman0122011-02-16

I'm on iPad right now, so if something makes no sense due to a random word, it's probably the fail auto-correct.

I will get a pic of a dc barrel jack and post it when I get to my desktop.

As for making it change color to the different songs, that would be easier to do with Arduino or microchips and what not, and I deal in analog circuits. But you can make the color change as the song is playing. Like I said, it would be about adjusting a few resistor values and the capacitor value, and then making a simple audio...I think its called a crossover, but it's pretty much just a filter. There is an excellent 'Ible for a filter, it would need slight tweaking I think, but it would go to the inputs where you touch your fingers to. I will reply later tonight or tomorrow (ASAP) on what would need to be done, and I will try and get a new schematic drawn up too, and will include the link to the other 'Ible for the audio filter.

Eman012 (author)Wesley6662011-02-17

How can I connect the battery pack? Can I use this instead of a DC Barrel Jack? And can it be power supplied even it has a battery? And what can I use as an alternative touch sensor? And what is the main base of the lamp? Sorry for asking too many question. :|

Eman012 (author)Eman0122011-02-18

And what LED did you used?

Eman012 (author)Eman0122011-02-18

I just want to say that its a bit hard to do. Specially if you don't know anything about electronics like me. haha. :D

Wesley666 (author)Eman0122011-02-19

Everyone has to learn somewhere.

Eman012 (author)Wesley6662011-02-21

Thank you very much for your help!!!! :) I'm still working on it. Trial and Error. :| And instead of color blue, I used color yellow. is that ok? And I didn't put the touch pad yet, and the color is not changing.


Wesley666 (author)Eman0122011-02-21

Yellow? Odd, but you should still be able to make some colors, not as many as blue tho probably...but then again, they make TVs now with yellow, but it still has blue. In actuality, the four colors that should be used are like cyan, magenta, yellow and something else, and that makes every color, including brown and black, but they dont make LEDs in those specific colors, but that's how printers work, and I assume it would work for this as well, but its just a theory...

Ok, I'll get on the touch pads right away, and your welcome! :D

Eman012 (author)Wesley6662011-02-23

Oh. Ok. :)))) Our science fair is tomorrow, and I'm done with the lamp. It's not brighter than yours, but I can make the colors blend with the touch pad. :)))) THANK YOU VERY MUCH. :D :)

Wesley666 (author)Eman0122011-02-23

No problem and it's good to hear you got it working! :) Upload some photos sometime if you can, I would love to see it! Good luck at the science fair! :D

Eman012 (author)Wesley6662011-02-25

Hey! The science fair is over, and it was fun. :))) My teachers said that the lamp is so cool and beautiful. Only one teacher said negative things and criticize it, but nevermind. :D Thanks for everything again! Especially for helping me and for this lamp!! :)))

And BTW, I don't have any pictures because I was too busy working on my paper works and this lamp. :D

Wesley666 (author)Eman0122011-02-25

If you have time now that your not busy with the lamp and papers, pics would be excellent, I have been waiting for someone to post pics of theirs, I really want to see other ppls work, but its fine if you can't. What did the negative teacher say? There is always one negative person isn't there?

And your very welcome! I enjoyed helping out! :D

Eman012 (author)Eman0122011-02-21

BTW, I didn't put the touch pad yet. But if I put it, the color will change right?

Wesley666 (author)Eman0122011-02-21

I will get the touch pads up ASAP so you can put them in. Yes, you use the touch pads to change the color, until then it won't do anything...

Wesley666 (author)Eman0122011-02-19

I used 3 LEDs of each color, so 9 in total. They are ones from Radio Shack, they are the square shaped ones, and are similar to Superflux LEDs. I have a picture of them on step 1 and on step 4 there is a picture of them on the board.

Wesley666 (author)Eman0122011-02-19

Yes, you can use a Battery Pack instead of a DC Barrel Jack. I would suggest 4 D batteries or 4 C batteries, just because they will last longer. You could use 4 AA's or 4 AAA's but it wouldn't last as long. If whatever you are putting this in has enough room, go for bigger batteries, just make sure the voltage is about 5-6volts. An alternative touch sensor? Well, if you need this for a science fair or something, I would stick with anything conductive for them. Unless you want to do the music frequency color adjustment. I could help with that, but you would need some time for that. I would stick with my design for the Science Fair and you can tweak it afterward. The main base of the lamp? Like an enclosure? I still haven't put mine in anything. You can put the circuit just inside a Glad container and run the LEDs up on top and do as I did and put a paper cone over them. But its really up to you, what you want to put it in.

There are never too many questions as long as you are asking because you don't know, and not because you want to be a pain.

Wesley666 (author)Eman0122011-02-19

The included picture is of a DC Barrel Jack. It has 2 or 3 pins, one for positive and one for negative and if it has 3 its just an extra positive or negative, I can't remember which. This is so you can plug in a wall adapter to it.

Wesley666 (author)Eman0122011-02-19

One of your messages said you were confused (as was one other person) about the touch pads. I will update the Ible in a day or 2 and will also post a reply to your message so that I know you get it. :)

Wesley666 (author)Eman0122011-01-29

Wait, srry, I am probably over thinking this, but do you want the color to change when the song changes, the music to change when soothing adjusts the color, or you want the lights to flicker with the music, but adjust their color to the music? Srry, I am over thinking word what you want it to do and I will make sure I under stand it on the next comment! :P

Eman012 (author)Wesley6662011-01-30

I want the color to change when the music changes...

Wesley666 (author)Eman0122011-01-31

Ok. Gonna need to thin about this for a second. Like when the song changes it changes color or it changes color with the music? Changing color with the music would be easier I think. I have a bit of an idea for that if that's what you want. Changing color when the song changes would be harder. Lets see. I will need to get a filter circuit to filter Bass, Mid and Treble Frequencies, and each one can control a color rather then the touch pads, but, the capacitors would need a smaller farad rating and the 10k ohm resistor would need to be smaller, so that any pause in the music (Or that frequency) that the cap will start to discharge a bit, otherwise the lamp will just get to white light eventually. I will do up another circuit diagram and post it of my idea, and I will start testing some of it on my breadboard.

Eman012 (author)Wesley6662011-01-28

And what is the size of the bread board? Sorry for asking too many questions. :)

Wesley666 (author)Eman0122011-01-29

You only really need a bread board if you want to build it, test it first, without having to solder everything right away. They are handy, so I would suggest buying one. They are about 3 inches wide by 8 inches long would be the size you would want.

hunter566 (author)2011-01-12

Im totaly confused on what are the touch pads supposed to be ?

Wesley666 (author)hunter5662011-02-19

You and someone else are confused on the touch pads, so I will update in a few days of what the touch pads are/work like.

Wesley666 (author)hunter5662011-01-12

They are anything conductive. There are 4 pads. One, the largest and the one that you always have to touch while touching one of the other 3 is simply connected to positive. The other three each correspond to there own color and connect to the base of the 2N3904 NPN Transistor that adjust that color. When you touch the positive pad and one (or more) of the color pads simultaneously, the corresponding color(s) will begin to gain power and then by the length of time you keep your fingers connected the brighter they get so you can adjust brightness and mix colors.

If this doesn't answer your question, reply, and be more specific, like what about the touch pads? Material, how they are connected...?

Eman012 (author)2011-01-26

Is it ok if the value of the 6 ohm 1/4 watt resistor is 6.8 ohm? Reply please ASAP.

Wesley666 (author)Eman0122011-01-26

Should still work, but you will have to touch the pads a bit longer before the LEDs gain enough power to be visible. Shouldn't be too much tho. So yes, that should be fine! :D

MANIAC (author)2010-09-08

would i be able to substitute the LED's with el wire? if so, what modifications would need to be made?? thanks:)

Wesley666 (author)MANIAC2010-09-08

What voltage does the EL Wire take? Is it 120vac or 12vdc?

MANIAC (author)Wesley6662010-09-09

it would most likely be 120vac

Wesley666 (author)MANIAC2010-09-09

If you where using 120vac then you would need a slightly modified circuit. Since LEDs are Diodes and half rectify the power anyhow, you could use High Power Transistors, as they also half rectify power. This is because since you only care about half the sine wave, you wouldn't need to use expensive Triacs to keep the full sine wave. So upgrade the Transistors to higher power ones. The resistors would probably need to be 1/2watt resistors. The capacitors would need to be at least 125v caps, maybe a bit higher just as a precaution. Since I think it would be hard to find a 1000uf 125vdc capacitors I would suggest finding three identical caps with the highest Farad rating and adjusting the resistors accordingly. The best place for this would be to go get 2 or 3 old computers for cheap/free with the power supply still in them or just the power supply. Each power supply has to large caps in it, they are usually 200v 470uf. These would work, but grab a few extra power supplies because the values from one to another can change a bit so to find 2 power supplies with 470uf might take a few tries. I would also say since these Transistors probably would take a bit more power at the base lead then the ones I used, turn the 10k ohm resistors into 33k so that the lights don't dim immediately. As well since the Farad rating is lower, you may want to try a 10 - 50 ohm 1/2 watt resistor in place of the 6 ohm one I used. You probably wouldn't need the 330 ohm resistor I used. So in general, higher powered parts and a few value changes, and it should work, is what it comes down to I think.

MANIAC (author)Wesley6662010-09-10

ok i'm fairly new to elctronic building so bare with me. i know a little but some things i find difficult. i basically have a border in my bedroom about a foot and a half from the ceiling. i wanted to stick red green and blue el wire on top of it all the way round so the ceiling is basically lit upbut the wires would be out of sight. that means the circuit would have to power many feet of el wire by mains power. what parts would i need and how would i apply them? i live near an electronics shop so it would br helpful if the parts could be bought from there. also, is there anything i could use instead of the computer power supplies since i can't really get hold of any cheaply. sorry for the questions and my little knowledge but the help is much appreciated:)

Wesley666 (author)MANIAC2010-09-10

You just need to caps that are in the power supplies, but if you can't get them check with your electronic store. They should sell everything I mentioned above. Bring a list with you it helps. I will make a new circuit diagram and parts list for you so you can go get what you need.

Also, do you want each light slowly coming on like mine, or is it, I want them either on/off? And when you do build it, if you want the colors come on slowly and mix to get any color, you would need some kind of translucent tube, then twist the wires around (Braid possibly?) that way you should get a good, even mix.

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