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LED VU Meter Coffee Table Answered

I'm working on building a VU meter that will respond to ambient noise into a coffee table that I am making, and I'm stuck on working out how to build the VU Meter circuit, and how to power all the LEDs. I planned on using a 10 LED VU meter kit, and somehow powering more than one LED for each subsequent step. The thing is, each level doesn't have the same amount of steps. The first four levels have 8 LEDs each, the next three have 16 LEDs each, and the last three have 24 LEDs each. The LEDs I'm using have a forward voltage of 2.0 volts, and a Max Power Dissipation of 105 mW. I don't know how to go about powering the LEDs or wiring the circuit. Any help would be much appreciated.

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øPossum (author)2009-07-01
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Ora (author)øPossum2009-07-01

Wow, thank you so much for making this. One question though. I was thinking about it more, and is there any reason I couldn't simply use one of the kits, and attach more LEDs in parallel?

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øPossum (author)Ora2009-07-01

Many of the kits use a LM3916 or LM3915 chip. With a 12 volt supply each pin can have up to 4 red LEDs in series. With a 20 volt supply each pin can have up to 8 red LEDs in series. Using several kits would allow the number of LEDs that you want.

12 volt schematic
20 volt schematic

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Sandisk1duo (author)2009-06-30

can you show what vu meter you used? something you can do about the steps of the meter, don't use every led, instead just skip one what color leds came in the VU meter kit?

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Ora (author)Sandisk1duo2009-06-30

I haven't purchased a kit, I was going to get one once I figured everything out. I have a couple hundred red LEDs that I'm going to use instead, and I want to use all the steps, but for each step I need to power multiple LEDs.

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Sandisk1duo (author)Ora2009-06-30

oh i see... well since you're going to use red leds, the voltage put out by the kit will be 1.7 (red leds' forward voltage) since your leds will need 2V, it might work, but you would have to wire only replace one led with one led give me the website of the VU meter, and i can give you more details

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