This is my modified circuit diagram to be used with motadacruz's Music LED Light Box Instructable.

The idea is that, instead of only using one channel from your audio cable, by using two transistors you can use both channels and wire them to separate LED strings. Here I only show two LEDs in each string, but I'd recommend at least 6 for each.

Also, I decided to use USB to power my circuit. No more hefty dc adapters clogging up your power strip! I included a helpful USB cable diagram to tell you which wires you'll be needing.

I did not include resistors in this diagram because that largely depends on the type and how many LEDs you want to use. If you need help determining what resistors to use, this is a helpful resource to bookmark: http://ledz.com/?p=zz.led.resistor.calculator

If you find a mistake in my diagram, please let me know right away so I can fix it.

Here's a higher resolution of the image: http://i.imgur.com/O0MPL.jpg
<p>Trying to use your circuit for a project. I do not have a Tip31 Transistor. See images of a kit that I have. Is there anything comparable that should work very similar to your Tip31?</p>
I tried this once. The lights are very dim. They take what one channel does and halfs it between the two sides. But if you put an OP-Amp circuit before the leds, it works reall well.
<p>Where do you find the OP-Amp circuits because I can't find any :/ and how did you connect it all? Do you have pictures of how it was done?</p>
how many leds I can use with a single usb connector?
Does it have to be a TIP 31 transistor or could it be any kind of NPN.
Took several tries but here is what I mean Hope this helps
Thanks for that helped heaps got it working great now :)
The two ground lines coming out of the plug threw me for a second, but otherwise good digram. Sneak over to radio shack and get a couple of 276-2017.

About This Instructable




Bio: I am a Computer Engineering Student interested in learning more about my Arduino Uno.
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