LED's flash with music

[supercool]

I am wanting to put have a few LED's flash with the intensity of my music. I don't need a color organ, but just want the LED's to flash in sync with the music. I am amplifying the signal with a LM368 chip and playing music from a 4ohm 3W speaker and it's sound quality is great. The problem is my LED's don't turn on at all..


Does anyone see a problem with my circuit or know of a reason the LED's arn't turning on? Any advice would be appreciated

Thanks

[Dave H]

You could have destroyed the transistor. It needs a resistor in series with the base to limit the current and a diode from base to emitter to protect it from reverse bias. There are too many LEDs. The forwards voltage drop of four LEDs is more than the 5V supply and they also need a series resistor to limit the current. I would have the LEDs in parallel each with its own series resistor.

[Mark Hammer]

Some 40 years ago, my wife's biology department was having a Halloween party. I had very little time to prepare any sort of costume, so I rushed home, soldered a pair of red LEDs together such that one LED was poking out of each nostril, and ran some thin wires from the LEDs over my ears and down my sleeve to a battery and momentary switch hidden in my hand. The whole evening, people kept coming up to me and asking how I was able to get my nose to light up in time with the music. The lighting was dim so the wires were not visible. Of course, being the heyday of disco, it was a pretty simply matter to time the button presses to the 120bpm tsss-boom-tsss-boom-tsss-boom that pretty much captured every tune being played.

[eschertron]

Some 40 years ago, my wife's biology department was having a Halloween party. I had very little time to prepare any sort of costume, so I rushed home, soldered a pair of red LEDs together such that one LED was poking out of each nostril, and ran some thin wires from the LEDs over my ears and down my sleeve to a battery and momentary switch hidden in my hand. The whole evening, people kept coming up to me and asking how I was able to get my nose to light up in time with the music. The lighting was dim so the wires were not visible. Of course, being the heyday of disco, it was a pretty simply matter to time the button presses to the 120bpm tsss-boom-tsss-boom-tsss-boom that pretty much captured every tune being played.

And Reindeer horns complete the costume!

[Enzo]

Don't need a color organ? Fine, just build one channel of a color organ.

[supercool]

You could have destroyed the transistor. It needs a resistor in series with the base to limit the current and a diode from base to emitter to protect it from reverse bias. There are too many LEDs. The forwards voltage drop of four LEDs is more than the 5V supply and they also need a series resistor to limit the current. I would have the LEDs in parallel each with its own series resistor.

I got it. Thank you.：灿烂的笑容：