This is a very basic circuit for syncing LED's to music.
There are several issues:
1. You do not need a 9volt power source, I have used 3volts and it worked
2. Depending on your speakers system setup you will have turn the volume up very loud
- I have connected this to a Latte Ipearl mp3 player, the volume (0-32) had to be a 26 to get the LED to start to blink.
3. Make a amplifier to correct problems with volume having to be very loud.
4. I could not get this work using headphones; it did not work because I could not get the enamel of the headphone wires, so I cut open the headphone jack and connected my own wires.
5. If you have an equalizer you can adjust the different frequencies to and the LED will blink accordingly.
Step 1: Connect and Enjoy.
Materials: (scavenge electronics if you can)
Power source - 3volts to 9volts should work
Resistor - 220ohm, though I have used 150k and it worked
TIP31 NPN Transistor (Negative Positive Negative)
DO NOT HAVE POWER ON
1. Connect the resistor to the power and the positive side of the LED
2. Connect the negative (look for the flat side) of the LED to the center pin (collector) of the transistor
3. Connect the positive side of your audio signal to BASE on the transistor
4. Connect the negative side of your audio signal the Emitter of the transistor
5. Connect the negative side of your power source Emitter of the transistor
6. Turn on your power source, turn on you audio, turn up the volume and experiment with a equalizer (VLC player has one built in to the software and it is free)
Step 2: Placement of TIP31 NPN
Step 3: Be Positive
Step 4: 220ohm Resistor
Step 5: You're Grounded
*ground is the negative of your power source or battery
Step 7: You're Grounded Again
Step 8: And Again
Step 9: Something Positive
always good to connect power last so not as to fry anything.