audioguru: oh wow, i see. Well thanks for the lesson, i really appreciate this. um, what type of IC would be/have been ideal for this project? i'll get a few on my next order to jameco. -Joe

 

what type of IC would be/have been ideal for this project?

My design uses an LM386 little audio power amplifier that has enough output current to drive many (20?) LEDs each with its own current-limiting resistor.

 

My design uses an LM386 little audio power amplifier that has enough output current to drive many (20?) LEDs each with its own current-limiting resistor.

but that's what I have. Why does the LM386 work for you but not for me?? -Joe

 

Why does the LM386 work for you but not for me??

In post #9 I showed how a capacitor from pin 1 to pin 8 boosts the gain 10 times.
I also showed how to power and connect an electret mic.
Try it without the 1N4148 diode which might be connected backwards.

 

In post #9 I showed how a capacitor from pin 1 to pin 8 boosts the gain 10 times.
I also showed how to power and connect an electret mic.
Try it without the 1N4148 diode which might be connected backwards.

there's not diode in that circuit; so i'm confused as to what you're getting at. -Joe

 

Post #7 has my LED Music Pulses Circuit with an extra 1N4148 diode and capacitor to keep the LED lighted long enough to see very short duration pulses. It has a line-level input from an MP3 player.
Post #9 has the LM386 amplifier with an electret mic input. It does not show the parts to light an LED that are in the other circuit.

Simply put the two schematics together.

 

aaaaaaaaaah, why didn't you just say that?! thanks! haha, i'll try it. Worst comes to worst, at least i figured out how to make a clap-on/clap-off circuit. -Joe

 

okay, so it's working, and even has that fade which is pretty cool. Thanks to everyone, especially audioguru, that helped and contributed their ideas.

HOWEVER...if i say, wanted to be able to detect a "pin drop" in another room and hook the circuit up to a LM3915/16, what might the amp/mic-circuit look like. I'm pretty sure I've seen this done with a lot less circuitry than what's hooked up to my breadboard right now. -Joe

 

question! how come this circuit doesn't work for me?? It's meant to modulate the IR LED and have a receiver demodulate it and pulse the signal through a speaker. it doesn't work, or at least, it doesn't work on a regular LED (i haven't tested out the full circuit with the receiving end). When I apply the 9V, the LED just turns on at about 60% power. Any ideas?? -Joe

 

question! how come this circuit doesn't work for me?? It's meant to modulate the IR LED and have a receiver demodulate it and pulse the signal through a speaker. it doesn't work, or at least, it doesn't work on a regular LED (i haven't tested out the full circuit with the receiving end). When I apply the 9V, the LED just turns on at about 60% power. Any ideas?? -Joe

My circuit blinks an LED to the beat of the music. The LED is turned off without any music, unless you built it on a breadboard where all the long connection wires are antennas picking up radio signals and mains hum.

Do you want to transmit the music (or voices) using IR? Then a different circuit is needed. It would use a carrier frequency so that the LED is always turned on and AM or FM modulation can be used. Maybe supressed carrier single sideband can be used so that the IR LED is turned on only when there is modulation.

My new sketch shows the parts that are on the other schematic for the microphone to work, and it shows why the LED is turned off without a signal:
This circuit will simply cause an IR receiver to produce a click for each beat of the music.

 

alright, i'll give that a try in a few days. I got that circuit out of "101 Spy Gadgets for the Evil Genius", but haven't been having much luck for the circuits in the book. -Joe

 

I got that circuit out of "101 Spy Gadgets for the Evil Genius", but haven't been having much luck for the circuits in the book. -Joe

We explained why the extremely simple circuit does not work.