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Music Response LED Necklace

Scott S

Jul 4, 2010
1
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Jul 4, 2010
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I am making a Led necklace that blinks in response to the music. I need help designing a circuit that takes the music output from a mp3 player and makes about 20 leds blink in response to the music. The leds are either going to be blue and white or blue and purple. I need for this circuit to be battery powered. Also the circuit should be able to be formed into a necklace neatly. Another option for the circuit is having the "guts" tucked inside a pendant.
I need ideas on how to do this. I also need help designing the circuit.
Thanks for your help,
Scott
 

cspannos

Jul 24, 2010
14
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Jul 24, 2010
Messages
14
I'd love to see the design if you wind up getting any help. Sounds like an awesome little project!
 

Externet

Aug 24, 2009
891
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Aug 24, 2009
Messages
891
You only need an audio amplifier.
Depending on its output level (and power supply) you connect leds in series or in parallel to it.

All leds should be paired in counterparallel.

Audio (+)----------------|>|-------------------(-)audio
Audio (+)----------------|<|-------------------(-)audio

Try the ultrasimple schematic above for a single pair of same color leds and connect it to your home stereo speaker output. Be very gentle with the volume control, just to obtain the flickering. Too much volume will burn them. Measure the AC voltage across the leds, will be around 2V. That is the output your necklace audio amplifier should provide to light them up.
To fine tune them, install a resistor in series to each pair to limit the current at maximum volume

There is a good chance that a single pair or perhaps a few pairs can be driven directly from the earphone output of the MP3 player, but do not risk the health of your player. It is not meant to drive leds.
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
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Jan 21, 2010
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25,510
I might consider something like an LM3915 in dot mode and have the various LEDs in different colours randomly arranged around the necklace.
 
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