Can anyone help me build a schematic for audio controlled LEDs?

I would like to make an array of music controlled LEDs somehwat similar to this video. https://www.youtube.com/watch?v=HPhm8VTCWpg

My purpose is to put it inside an Infinity Mirror kind of like this one
http://www.youtube.com/watch?v=kkAVDtMaT84

I will be replacing the Audio jack with an electrolet microphone later (dont know how yet.)

I am a noob when it comes to circuits, I have been trying to learn these things but I have not really gone anywhere by myself. I downloaded PSpice but I cannot even begin to understand how to use the darn thing.

I would like to know how to set up the LED array so that I can power 150 to 200 LEDs with 12volt power supply. Can anyone please help me or point me in the right direction? I would really like to have this done by the first of January as I'm planning on giving it as a present.

chinusta said:

I am a noob when it comes to circuits, I have been trying to learn these things but I have not really gone anywhere by myself. I downloaded PSpice but I cannot even begin to understand how to use the darn thing.

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Use google to find out more about NPN transistors/LEDs. I'm not an EE but learnt quite a bit through internet research/reading datasheets. Don't know though what you want to simulate through PSpice. The schematic is very simple and already given in the instructable (I design a my schematics/boards in EagleCAD)

chinusta said:

I would like to know how to set up the LED array so that I can power 150 to 200 LEDs with 12volt power supply.

Click to expand...

Use LEDs series in series parallel configuration and separate current limiting resistors for each string. You could put 3-5 LEDs in series depending on the LED color/ votlage drop. Now consider the following only as my rant!




The instructable linked to the youtube video just uses TIP31c, with line level audio signal fed to its base. It basically means, when audio signal is high and has positive voltage, the transistor (and therefore the LED) will turn on harder. I've done it in the past, and it sucks because:

1. Since audio waves are ac and no rectification is done, you'll see a lot of flicker, especially with low tones. This also means reduced LED brightness since LED stays on only half the time.

2. When your volume gets too high, LEDs will stay on all the time, and the opposite when volume is low.

3. Can't distinguish between a short burst of sound (beat) and a continuous loud signal.

4. Can't distinguish between bass/mid/treble (can be done using additional filter circuitry/ multiple channels)

Some people at MIT did an open source project which partly addresses these issues (a short demo video here). I think syncing light to sound has been a serious business e.g. consider the expensive lighting equipments used in electronic dance music festivals, some are pre-programmed I guess. The problem becomes harder when you have to do it online with low latency, i.e. no pre-programming.

Thank you!...I guess I have a heck of a lot to learn. I will be asking a few classmates who have taken circuit classes before to help me as well.

Sorry, I was in a ranting mood, I'll still advise you to build that basic circuit (and read the instructable). It did please me for a week, until I realized the limitations and grew out of it. See here for some cool stuffs using infinity mirrors.

It is so simple, just put the led in the wires of the speaker and it will glow as the music sounds:thumbsup:

try 555 timer cookbook, this one is a classic