LED Light Box Thumps to Your Music

what is the max amount of led’s you could use i was thinking 100 would be amazing

100 would indeed be amazing If you have a powerful power supply and hook up the LEDs properly, it can be done. Check out http://www.ledcalc.com for some help.

Is the brightness of the LED’s determined by how loud the music is?
How loud can you turn the music up (so what’s the highest voltage), before the transistor starts pumping too much power to the LED’s?

No, it doesn’t quite work that way. Basically, when music is played, a switch is closed which gives power to the LEDs. You can set up the circuit so it won’t blow out the LEDs.

To clarify on Joe L’s answer, the way to set up the circuit is the way shown, as long as you don’t overvolt the LEDs (use the calculator). The voltage to the transistor (the headphone lead) is not going to the LED chain, so it doesn’t matter how loud the level is to the transistor.

hey guys… i was wondering whether switching a microphone with the audio jack would work? as in background noise then sets it off?

Yes, you could run it through a microphone, but…you’d have to amplify the signal first. Voltage from the microphone is really really small, so you have to connect an amplifier between the mic and the transistor.

where did u get the clear box from to make this?

It’s hand-made with sanded plexiglass.

Where youd you put an amplifier/speaker. im guessing splitting the wires between the transistor and the audio jack

Yeah, you just use an Audio splitter – http://bit.ly/bDSOtS

how many volts did you use to power the six LEDs you used?

12v

can you give a link to download the songs you used?

I don’t think they’re downloadable (they were made custom). You can strip them out of the video though for a rather poor quality version.

Hi just a quick question! What type of transistor is it? I am finding tip 31A and also tip 31C, so i just need to know which one to use!

They probably will both work.

There are a couple of modifications that I’d like to do, but am not sure how.
1) I’d like to be able to use a 9volt power supply (battery/wall wart). Do I need a resistor…if so, what type?
2) I’m wondering if the input signal could just come from a contact microphone?
Thanks

Okay….so I figured out the answers to my two questions. I used a 9 volt transformer and put a 220 ohm resister in the chain before 4 leds. So the lamp part works. Also, I reread the comments above and saw the answer about a microphone (needs an amp.)
New question: Can I use a splitter of the speaker cable of my guitar amp, or is it better to sequence this after the speaker…or something different?

@H20Rider – You probably won’t notice a difference based upon where you place the splitter.

Thanks, Joe. One last question (I think)..Will adding a splitter adversely affect my amp’s transformer. It drives an 8 ohm speaker and if an amp’s load is reduced, I understand an amp’s tranny can burn out. So, would adding this circuit reduce the load significantly?
BTW, the amp in question is a 10 watt tube amp. There’s no headphone jack or effects loop. Thanks in advance for any help.
G

Hmmm….I’m not really familiar with amps…but I really doubt splitting the signal would do any damage.

Thanks Joe. Well, I used aligator clips too connect to the speaker terminals, and used a 9 volt converter for power. I have 4 UV LEDs and included a 220 ohm resistor. It actually seems to be working quite well. I’ll keep a eye (a thermal eye, that is) on the transformer to be sure it’s not overworked. I don’t know if the resistor is necessary, or if the LEDs and transistor offer sufficient resistance to keep from blowing the LED. In any case, the effect is very nice with the pulsing light emanating from deep inside the amp chassis.
Thanks

Just so you guys know i tried TIP 31a and TIP 31c they both work but 31a seems to be slightly more sensitive my comparison i cann tell the one you used in the vid is the TIP 31A .

I bought this
http://hacknmod.com/store/index.php?act=viewProd&productId=424

And i will use 12v battery.

So do i need resistors? I dont want that leds blow up =/

Depends on your configuration and amount of LEDs. Use http://www.ledcalc.com to decide.

Here is a question. I would like to make the light work in sequence….The louder the music the more lights will light like a graphic bar…maybe 4 bars with about 50 to 100 led’s in each bar on the ceiling in my den…now that would look cool!!!!

That’s called a VU Meter (VU=volume units). We have a few posts about them on HacknMod to check out.

What if I want to use this for a PC soundcard ?
It only has one Line Out jack , and it’s for the stereo desktop speaker ?

Use an audio splitter – http://www.hacknmod.com/store/index.php?act=viewProd&productId=200

i made this and hooked it up to a A23 12v battery and it’s not working. I used the ledcalc site because I’m useing 5 leds. Right nowI have a 270 Ohm resistor going to two LEDs and a 150 Ohm resistor going to the other three. I check the LEDs and they aren’t fried. Any ideas???

check the polarity of the battery and LEDs

Thanks for the help. Still don’t know what was wrong but it is working now. I think it may have been I didn’t have the volume high enough. Is there a way that I can make the LEDs flash work at a lower volume level so I don’t blow out my ears?

Use an lm386 chip to amplify the audio signal going to the LEDs

is it possible to use 2 tip31 one for the left and one for the right audio ?

yes!

thanx man here’s the stereo version I make http://www.youtube.com/watch?v=LBb1Kr1E7OE

@mozartripper – Awesome touch with the frosted bottles

You said you used a 12v battery to power your 6 LED’s but isnt each LED 3.5v? I punched all this in on the ledcalc website to see weather i needed a resistor because i wat to do a LED with a 12v battery but it doesnt work out. Or am i doing something wrong?

@sergio – some LEDs are 1.8-2.2v which means 6 of them could be illuminated using 12v.

hi joe,

I have hooked an audio splitter to the output of my pc. The LEDs blink and sync fine to music when only the LEDs are connected.
When I try to hook my headphones to the splitter so I can hear the music as well, the LEDs no longer blink.
Is there not enough voltage output/power or something?

Hmmm…could be indeed. You could look up an LM386 audio amplifier to help amplify the voltage going to the LEDs (google it). There are probably some instructables which use it too.

I was wondering if there was any 110V AC to 12V DC converters that would work to replace the battery. All the ones I have are 9V max, and only about 500 mA. I wanted to run a few of these blocks off of one power source. Thanks!

@highflying: Yes, just buy a wall wort and cut the wires.

I make the same one but with a little upgrade:

I’m using 8 LED for each side of the speaker (left right) all pluged in // and I use a USB connection to power them!!

Then to make them brighter, I use a 74ls14 to put more power in the transitor so the light is around 60% bigger. but to take out the noice in the sound, I putted diode 1n914 at the source of the signal. and here you go

a nice upgrade of your schematic!

Hiya, Amazing Job on such a simple idea, I would love to know whether you sold these things?? I would buy one of these if you doubled the amount of LEDs up to 16…

Hi, I tried this circuit and it works like a charm, on my PC with almost max volume. The only thing I can’t figure out is how to make it more sensitive. I need it to trigger if there is any sound at all, so it would run off a MP3 player or my Jabra BT3030 bluetooth receiver for example.
Also I need the circuit to be really tiny, or as tiny as possible.
Help would be greatly appreciated.
Thanks, Milan

@Milan

Get another transistor or two and set them up in a “darlington pair”.

Got mine working… a little different though. I have mine powered by a 12v power adapter, and wired to my homemade subwoofer box. I used a TIP31C. It’s not complete yet (I plan on having about 16 LEDs wired under the box), but it works wonderfully so far. Heres a short video. http://www.youtube.com/watch?v=3huEYDB_hUM&feature=youtu.be

Low Voltage transformers (ELV or MLV) are tirkcy. Just because you have the voltages the same doesn’t mean you have the right current being drawn by the LED’s.It could be too low or too high.Were the original halogens MR16 form factor as well?I’m guessing the xfmr was specifically designed for a set voltage/current/power.Consider this:Two 20W halogens = 40W.Power=Voltage*Current20=12*II = 1.67 amps through each bulb, 3.33 amps total drawn from the xfmrTransformers operate on the principle of Power in = Power Out. The xfmr is probably designed to provide 40W, regardless of whatever current draw you put on the transformer.The LED’s only need 6W from the xfmr. However, the xfmr probably doesn’t care. It’s still spitting out 40W at 3.33A. 0.5A (2*3W/12V) is all the LED’s need. If the xfmr is still trying to provide 40W at 0.5 amps, the output voltage is compensated up to 80V coming from the xfmr. Most LED bulbs have protection for this in the engine, (the regulator/stabilizer as you call it), called over-voltage protection. This is probably whats causing the bulbs/transformer to fail.The problem is, especially with transformers, is that you must match the load. If the transformer is expecting a specific load and you give it something it can’t handle, it’ll either destroy the load or damage the transformer. The easiest way to avoid this is to always match the power of the original load to the load you intend to put in. 40W of halogens should be matched with 40W of LED. This is the gimmick with retrofit bulbs like the MR-16. You’re not really saving any energy when you use retrofit bulbs. You just get a longer bulb life and a lot more light from the same power draw.LED lighting is a niche market. If you can’t figure it out, wait a few months and LED lighting fixtures will decrease as the market is flooded with new product and becomes more competitive. I’d recommend investing in something like that instead of retrofitting.

I searched for hours to find a “Speaker output activated LED circuit” . Finally found this. I prototyped it last night & built it today. Fantastic. My prototype used an NTE157 and it worked fine until I could get to the store for a TIP31. Next I’d like to figure out how to build one that triggers off a low level signal from a headphone jack, like the headphone output on a Korg metronome.