Need some help - Sound driven strobe led panel.

[roccov12345]

Hi all

I'm looking for some assistance as I've been unable to find anything online for what I'm trying to do. I would say I'm a noob when it comes to electronic although I have built a few led lighting fixtures for aquariums, DJ equipment, etc.

What I want to do is build a 200 LED light panel that will strobe in sync with music for my brother's DJ career/birthday. The plan is to run 200 20,000mcd LEDs. Stats are 3.2 voltage drop at 24ma. Voltage source is 15vdc. The array will be 4x50 strings using 100ohm 1/4 watt resistors.

My question is: I found the signal circuit online which uses the tip31 transistor. I picked up a few at radioshack which say they are rated for 5v reverse drop. 40 watts max/3.0 amps.

The designed array will draw 1200MA @ 15 volts which I think turns out to somewhere around 18 watts. I found this circuit diagram off another thread and I'm wondering if this would work.

Any help would be GREATLY appreciated!

 

[4pyros]

that will strobe in sync with music

It will not strobe it will flash.
Do you what them all to go on and off at the same time?

 

[roccov12345]

Sorry I used the wrong verbiage, basically want them on and off to bass/sound of music. I forgot to add that the input will be from a laptops audio output.

 

[roccov12345]

Obviously the diagram I posted is not specific to my design. I guess where I'm getting confused is during the tip31 circuitry. I want to make sure I don't A burn up the transistor with 200 leds amp/voltage running through it and B not fry the sound card on the laptop. I also ordered a few tip42' since they were rated at higher handling watts/amps.

Now that I'm thinking about it. I think it would make more sense to design this wireless so he wouldn't just be jailed to the audio out of the laptop. Any ideas on how this would be done? Mic?

 

[4pyros]

Any ideas on how this would be done? Mic?

Yes alot of DJs lights work off a mic.
Google "bass light controlled by a mic circuit" or "bass beat LED controlled by a mic circuit"

 

[roccov12345]

Anyone know of any pre-designed circuitry for say electrec mic that would work with this?

 

[roccov12345]

I looked through the hits from the google searches but everything seemed a little too complicated for my current understanding. I guess my question remains, will something like the posted diagram work?

 

[audioguru]

The posted diagram has the 20k input resistor calculated for the 40V peak signal from a 100W amplifier.
The 220 ohm resistor was calculated to drive only one string of series LEDS when the supply is 13.8V.
it does not have a lowpass filter so it lights the LEDs for any frequency loud sound.

To drive more LEDs you probably need a more powerful transistor or a few of them and a driver transistor. They will need an amplifier to boost the tiny signal from a sound card.