sound/audio to light modulator

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sandiegoman
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sound/audio to light modulator

Post by sandiegoman » Wed Mar 10, 2004 1:51 pm

I am trying to make an inexpensive sound to light modulator using LEDs. Anyone know of any kits, or how I can make this? I would like a 7x7 matrix. 49 LEDs... <p>Thanks!<p>Bryan
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Chris Smith
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Re: sound/audio to light modulator

Post by Chris Smith » Wed Mar 10, 2004 3:01 pm

Lm 3914, 15, & 16

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jollyrgr
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Re: sound/audio to light modulator

Post by jollyrgr » Wed Mar 10, 2004 3:27 pm

You asked for a kit, here is one example:<p>http://www.hobbytron.net/vmk103.html<p>This is a four LED circuit but it gives you a base to start from.<p>This would be a simple color organ type circuit. I don't think that this is too difficult to do. But what you might be asking for is a seven channel bar graph. If this is true then you need what Chris Smith describes. LM391x chips are bar/dot drivers. Depending on how many channels you need is how many chips you need. I'm assuming seven since you mention the 7x7 matrix.<p>The LM391x series requires the chip, the LEDs, and a couple resistors. To make a bar graph display for different frequencies you would need to use different filters for the input to the LM391x. This could be as simple as a resistor and a capacitor. You would vary the cap for different frequencies.
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sandiegoman
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Re: sound/audio to light modulator

Post by sandiegoman » Thu Mar 11, 2004 1:07 pm

I would like to pay someone to send me a working example for a 7x7 matrix bar graph display. Each bar would respond to a different frequency with input through a mic. I would like to use ultra-brite LEDs for the project. Any advice would be greatly appreciated as well. <p>Bryan
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dacflyer
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Re: sound/audio to light modulator

Post by dacflyer » Sat Mar 13, 2004 11:51 am

well easiest thing for you to do is..you need filter circuits.theses will seperate the different frequencies before they goto the inputs of your LM3914's and then the LM's are easily built also...takes some time but you should be able to do it... hardest part is figguring all the different filters.. but most filters are as easy as capicitors and coils or resistors
maybe someone here can help you on that part..<p>i am guessing you want to build you something like a active equalizer display.. sounds cool.. i have this built into my equalizer here.. old one from radio shack years ago

Bernius1
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Re: sound/audio to light modulator

Post by Bernius1 » Mon Mar 15, 2004 5:34 am

WHAT YOU'RE LOOKING FOR IS AN AUDIO ' SPECTRUM ANALYZER '. GOOGLE SEARCH SPECTRUM ANALYZER, & YOU'LL FIND NEW,USED,KITS, CKT'S, ETC. MOST ARE AN ARRAY OF NOTCH FILTERS, MATCHING THE E-Q BANDS. (UNLIKE A TRUE SPECTRUM ANALYZER, WHICH USES A RAMP GENERATOR TO TUNE UP-&-DOWN THE SCALE).
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