This instructable diagrams a build of what is likely the worlds smallest color organ.  At just over the size of a postage stamp, it is very impressive for its size.  It uses an LM339 quad comparator chip to flash 3 colored LEDs in time with three separate frequency channels of a music input. 

Step 1: Parts

To build it, you will need a few things.  All of them are avaliable from Jameco.com, but I suggest that you buy one part from elsewhere. 
LM339 quad comparator
3 x 1k smd resistor (no bigger than 1206)
3 x 470 ohm smd resistor (no bigger than 1206)
2 x 1uf capacitor (no bigger than 1206).  I suggest yo buy this somewhere other than Jameco, since the minimum order quantity is huge for this component.  I just used through-hole capacitors for this one instead
2 x 0.22uf capacitor (no bigger than 1206)
2 x 0.1uf capacitor (no bigger than 1206)
1 x smd prototyping board for SMD 16-pin ICs
1 x audio connector, your choice
1 x 9V battery connector
3 x 500K potentiometers, or fixed resistors of many different values (CANNOT just use 470K resistors and get a "balanced" output)
3 x wires
3 x LEDs  size and power are your choice.  The maximum current from the LM339 is just about 16mA, so you cant use high power LEDs.  I suggest 3mm LEDs, blue for low, red for mid, and yellow for high, but that is yor decision.  The one in the pictures used one red 3mm led, and SMD blue and yellow LEDs.  The SMD LEDs were 5050, so I couldn't fit the red one in.
*optional*  you can add headers for an external display.  The output of the LM339 will drive PNP type transistors if connected directly to the base. 
<p>There are on-line schematic designers available that do not require and installaion on your PC (and as you are 5 years older now I'm sure parental controls are not an issue!?)</p><p>Look at Easyeda.com</p><p>Interesting article</p>
Thank you, but as you guessed, that's not really a problem anymore (not even living at home now). I have actually moved through several design tools at this point, starting with eaglecad, then gEDA, KiCad, and now altium Designer/Circuitmaker (basically the same software, Designer for commercial projects, Circuitmaker for personal).
Can this be done using any op-amp? Do you have a full schematic so I can do this on breadboard first?
1) the 339 is NOT an op-amp, that's the main distinction between this and most other designs. There's no actual amplification, just switching once the audio reaches a certain power level. <br>2) there's a &quot;schematic&quot; on step 2. The pinout for the smd and regular packages are identical. I'll try to make up a real schematic and put that in soon. Right now, the el wire color organ has an identical circuit, if you replace the transistor connected to the 339 with the LED.
Great job,but next time you might want to add a video of it working and write the schematics in cadsoft eagle. The free version should do what you need and jeremy blum has a great tutorial series if you get lost! <br> <br>Here are the links: <br>http://www.cadsoftusa.com/download-eagle/freeware/?language=en <br> <br>http://www.jeremyblum.com/2012/06/09/tutorial-1-for-cadsoft-eagle-schematic-design/ <br> <br>I suggest you go through the tutorials before you download eagle as it will make it a lot simpler!
Yeah, I know and I tried to get eagle, but parental controls (meh) blocked me from opening it, and my parents don't like allowing ANYTHING (and they're ticked off 90% of the time) so I cant get it. I'm also not allowed a Youtube account, so I can't post videos.
hack the parental controls. Look up how to do it for the specific control in google.
In a word: no. For one, those programs (command prompt ones don't work for vista, or for what I'm doing) and programs can't run without permission.

About This Instructable



Bio: Currently a student at Iowa State University in Electrical Engineering. I'm participating in several clubs, helping with research, and working, so I probably won ... More »
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