Need Help With Sound Acivated LED Project

[Jesse6131994]

Hey guys, just want you all to know that I'm a beginner with this kind of stuff. So far I have a somewhat working circuit, with one problem.

This is what I'm pretty much making, showing the circuit. (https://www.instructables.com/id/Music-LED-Light-Box/step6/Building-the-circuit/)

My circuit looks like that, except instead of the 12V battery I'm using a 12V DC wall plug. Also I have 4 LED lights all connected positive to negative and so on.

These are my LED lights I ordered and using at the moment. (https://www.amazon.com/gp/product/B007RO9X82/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1)

My problem is that the LED lights are very dim throughout most of the song. And sometimes they're unresponsive. What I did notice is that if I squeeze/press prong #1 on the Tip31, the LED lights get bright. When they go unresponsive, I give the first prong a little squeeze to get them going again. Why is this happening? Also, how come this circuit seems to work for everyone who makes this except for me?

I've been dealing with this issue for almost a week, trying to research as much as I could, but I came up with nothing and now here I am. Thanks everybody, much appreciated!

 

[N.Carsane]

'My problem is that the LED lights are very dim throughout most of the song. And sometimes they're unresponsive. What I did notice is that if I squeeze/press prong #1 on the Tip31, the LED lights get bright.'
Assuming this i'd suspect that the connection may be slighly loose so you could try re-solder it. Or there could be a short circuit so make sure the bare wires don't touch the othe bare wires.

 

[Jesse6131994]

'My problem is that the LED lights are very dim throughout most of the song. And sometimes they're unresponsive. What I did notice is that if I squeeze/press prong #1 on the Tip31, the LED lights get bright.'
Assuming this i'd suspect that the connection may be slighly loose so you could try re-solder it. Or there could be a short circuit so make sure the bare wires don't touch the othe bare wires.

Thank you for the reply. I didn't solder anything yet mainly because I was uncomfortable that this problem was occuring. I can try soldering and see if this solves it. Otherwise does my circuit looks good? But I'm also positive no wires are touching either.

 

[Reloadron]

The circuit you are using is a very, very crude version of what is commonly called a "color organ".

You have 4 LEDs in series and here is the data, what little I could find, on your LEDs.
Product Description
Just connect these light emitting diodes and they will show an impressive, fast-rotating color pattern. Forward voltage is 3.0-3.6 volts. Comes with 30 200-ohm resistors.

For your circuit to even begin to work (it's not a very good design) you need to get that transistor turned on. How much the transistor turns on will be a function of how much audio signal is driving the base. Now when you squeeze or make finger contact with the TIP 31 pin 1 my guess is you are adding some noise to the base lead turning the transistor on more. You need more audio drive signal and you may want to remove one of the LEDs and try 3 in series. Again, this is not a very good circuit or use of LEDs.

Ron

 

[audioguru]

The horrible circuit was "designed" by a 10 years old kid who knows NOTHING about electronics.
The transistor needs a fairly high level signal to turn on. A line level or headphones level is too low.

1) It is missing a current-limiting resistor in series with the base of the transistor so the transistor will be destroyed if a high level signal (from an amplifier driving a speaker) is used.
2) It is missing a resistor in series with the LEDs to limit their current to prevent the transistor and LEDs from burning out if a high level signal is used.
3) It is missing a diode parallel with the base-emitter of the transistor to limit the reverse voltage to 0.7V so that the transistor does not burn out if a high level signal is used.
4) The LEDs light only on the momentary peaks of a strong signal and for only half the time because the transistor is a rectifier. Then the LEDs will appear dimmed.

You need ordinary LEDs, not those color-changing LEDs. Ordinary LEDs can be connected in series and with a current-limiting resistor but a color-changing LED needs its own voltage-limited and current-limited supply.

 

[Jesse6131994]

The horrible circuit was "designed" by a 10 years old kid who knows NOTHING about electronics.
The transistor needs a fairly high level signal to turn on. A line level or headphones level is too low.

1) It is missing a current-limiting resistor in series with the base of the transistor so the transistor will be destroyed if a high level signal (from an amplifier driving a speaker) is used.
2) It is missing a resistor in series with the LEDs to limit their current to prevent the transistor and LEDs from burning out if a high level signal is used.
3) It is missing a diode parallel with the base-emitter of the transistor to limit the reverse voltage to 0.7V so that the transistor does not burn out if a high level signal is used.
4) The LEDs light only on the momentary peaks of a strong signal and for only half the time because the transistor is a rectifier. Then the LEDs will appear dimmed.

You need ordinary LEDs, not those color-changing LEDs. Ordinary LEDs can be connected in series and with a current-limiting resistor but a color-changing LED needs its own voltage-limited and current-limited supply.

Thank you for this reply. Is there a different circuit you can recommend for me? Do I really need to change the LEDs as I just ordered these and they came in yesterday.

 

[alec_t]

The seller of the LEDs says the colour cycle takes ~1 sec. If you are switching them in time with music then they may 'reset' to one particular colour each time the switch turns on (i.e on an audio peak), so would not have time to change colour. I agree with AG that you probably need ordinary LEDs.

 

[Jesse6131994]

The seller of the LEDs says the colour cycle takes ~1 sec. If you are switching them in time with music then they may 'reset' to one particular colour each time the switch turns on (i.e on an audio peak), so would not have time to change colour. I agree with AG that you probably need ordinary LEDs.

Yes I noticed with the dimness that it stays on red most of the time. Although, I noticed that sometimes it will not reset but still blink on and off while switching colors.

 

[audioguru]

Color-changing LEDs should never be connected in series and never used for blinking with music. The color-changing LEDs in my solar garden lights begin dim then slowly get brighter so they cannot be blinked by music.

You forgot to tell us what music source you have. Speaker level? Headphones level? Line level?

For a low level signal a power amplifier is used to drive some ordinary LEDs.

I developed this simple circuit. The LEDs are back-to-back so that one LED lights with one polarity of the signal and the other LED lights with the other polarity and the LEDs protect themselves from reverse voltage. The resistor value in series with the LEDs is determined by the voltage rating (the color) of the LEDs.

 

[Reloadron]

I suggested earlier you Google "Color Organ" circuits. Most of the stuff that comes up will give you an overview of how things work. The idea behind the poor circuit you are trying to use is an audio input is driving the transistor which in turn drives some LEDs. The transistor used is a transistor capable of driving a 5 amp load with a good heat sink. You don't need that. I would try a few simple LEDs and use a 2N2222 or any low power NPN transistor and drive a few low power (low current) LEDs with a series resistor. If you read the comments for the circuit you used most people had a rough time trying to get it to work.

If you like Instructables take a look at this little 3 channel color organ and note how the transistors are used. Note how the audio is coupled through a capacitor and how Q1 is used in the circuit. Are you trying to learn something here or just build a circuit the drive a LED to audio?

Ron

 

[Jesse6131994]

Color-changing LEDs should never be connected in series and never used for blinking with music. The color-changing LEDs in my solar garden lights begin dim then slowly get brighter so they cannot be blinked by music.

You forgot to tell us what music source you have. Speaker level? Headphones level? Line level?

For a low level signal a power amplifier is used to drive some ordinary LEDs.

I developed this simple circuit. The LEDs are back-to-back so that one LED lights with one polarity of the signal and the other LED lights with the other polarity and the LEDs protect themselves from reverse voltage. The resistor value in series with the LEDs is determined by the voltage rating (the color) of the LEDs.

So what LED lights do you recommend? (Specific ones that you have used before) I'm not completely sure what you mean by music source but I'll try to answer based on what I think you mean. Let me just say that my desktop computer is connected to my Corsair SP2500. (https://www.amazon.com/Corsair-Gaming-High-Power-Speaker-CA-SP211NA/dp/B004H0MQYW) The volume on my computer is always set at 100% and I adjust volume on the Corsair. I don't know what headphones level and line level mean. Unfortunately I don't understand the schematics you created completely. I understand the simpler portions of it but not all of it. I know I want to have a total of 6-7 LED lights in the finished product though.

 

[Jesse6131994]

I suggested earlier you Google "Color Organ" circuits. Most of the stuff that comes up will give you an overview of how things work. The idea behind the poor circuit you are trying to use is an audio input is driving the transistor which in turn drives some LEDs. The transistor used is a transistor capable of driving a 5 amp load with a good heat sink. You don't need that. I would try a few simple LEDs and use a 2N2222 or any low power NPN transistor and drive a few low power (low current) LEDs with a series resistor. If you read the comments for the circuit you used most people had a rough time trying to get it to work.

If you like Instructables take a look at this little 3 channel color organ and note how the transistors are used. Note how the audio is coupled through a capacitor and how Q1 is used in the circuit. Are you trying to learn something here or just build a circuit the drive a LED to audio?

Ron

I am googling Color Organs now, they all seem to be these complex schematics to me. I want to keep this as basic as I can while still working nicely. However I'm trying to build a circuit for this project to have something that would be cool with my music, while learning a thing or two wouldn't hurt.

 

[N.Carsane]

What is the max or the rated current for each LED?
Assuming that it takes 20mA have you tried 3 LED's along with a resistor (60Ω Minimum resistance) or without the resistor (the LED's could blow up without a resistor). I would only try it if I had plenty of spare LED's. The question is, is it worth the risk?

 

[Jesse6131994]

What is the max or the rated current for each LED?

3.0-3.6v

 

[N.Carsane]

I might think about doing this project with a TIP31C and 5 red LED's with a 60Ω equivalent resistor in series with 12V supply... Hopefully it will work

 

[Jesse6131994]

I might think about doing this project with a TIP31C and 5 red LED's with a 60Ω equivalent resistor in series with 12V supply... Hopefully it will work

Good luck, let me know if you have the same issue as me please.

 

[Reloadron]

I am googling Color Organs now, they all seem to be these complex schematics to me. I want to keep this as basic as I can while still working nicely. However I'm trying to build a circuit for this project to have something that would be cool with my music, while learning a thing or two wouldn't hurt.

OK, that says a lot. The little circuit that Audio Guru posted is a good example of a nice simple little circuit that will work and work well. I see you mention:

So what LED lights do you recommend? (Specific ones that you have used before) I'm not completely sure what you mean by music source but I'll try to answer based on what I think you mean. Let me just say that my desktop computer is connected to my Corsair SP2500. (https://www.amazon.com/Corsair-Gaming-High-Power-Speaker-CA-SP211NA/dp/B004H0MQYW) The volume on my computer is always set at 100% and I adjust volume on the Corsair. I don't know what headphones level and line level mean. Unfortunately I don't understand the schematics you created completely. I understand the simpler portions of it but not all of it. I know I want to have a total of 6-7 LED lights in the finished product though.

First LEDs have a forward voltage Vf which is the voltage they work at. They also have a forward current If which is the amount of current they draw. We know the Vf for your LEDs is between 3.0 and 3.6 volts but your LEDs really arent well suited for this type of application. When I looked up your LEDs unfortunately they don't list the forward current. Really matters not as was mentioned the LEDs you are using are not at all suited for an application like this. More on that later.

You mention you are using the audio out from your PC to drive a Corsair Amplifier. So what is really happening is a low level audio signal also called Line Out. Line Out is about a maximum signal level of 2 volts peak to peak or 1 volt peak or actually .7 volts RMS from a source impedance around 100 to 600 Ohms. So if we use Line Out to drive something those rough parameters need to be considered. Obviously your amplifier out uses a larger signal to drive the speakers.

Note how Audio Guru's circuit starts from the music source so we can vary the signal driving the LM386 amplifier. The amplified output of the LM386 then drives the back to back LEDs in pairs. There are some resistors labeled R lacking a value. This is intentional as the value of R will be selected to limit the current to the LEDs based on... Ta Da the If (Forward Current) of the LEDs. That is why with a good circuit we need to know the If of the LEDs used.

Ron

 

[N.Carsane]

Good luck, let me know if you have the same issue as me please.

I succeeded in the project and it worked just fine!
The 5 LED's were Bright (I had the general red ones) and they flashed to the song!
An upgrade would be to have a speaker in parallel to all the LED's, might try that...

Oh and why don't you try 3 LED'S and a 200Ω resistor (140Ω MIN), just replace the 1st LED with the resistor, tell me how it works out...

There's one thing though, you may never see the other colours as the music input always oscillates which is why it flashes very often hence why you wouldn't see the 2nd colour or 3rd colour.

 

[Jesse6131994]

I succeeded in the project and it worked just fine!
The 5 LED's were Bright (I had the general red ones) and they flashed to the song!
An upgrade would be to have a speaker in parallel to all the LED's, might try that...

Oh and why don't you try 3 LED'S and a 200Ω resistor (140Ω MIN), just replace the 1st LED with the resistor, tell me how it works out...

There's one thing though, you may never see the other colours as the music input always oscillates which is why it flashes very often hence why you wouldn't see the 2nd colour or 3rd colour.

Did not work. Still dim and slightly unresponsive. Thanks for the idea though!

 

[Reloadron]

I might think about doing this project with a TIP31C and 5 red LED's with a 60Ω equivalent resistor in series with 12V supply... Hopefully it will work

You don't need the TIP31C. Here is the data sheet for a TIP31C transistor. If you use for example 5 basic everyday generic LEDs they will typically draw about 20 mA with a forward voltage of around 2 volts. Using LEDs like these for example. Rather than place 5 LEDs (or any number) in series think about placing the 5 LEDs in parallel and giving each a series resistor. LEDs in series isn't a good design practice. So a max voltage of 12 volts with a Vf LED of 2 volts and If of 20 mA works out like this. 12 volts - 2 volts = 10 volts / 20 mA = 500 Ohms so use a common 510 Ohm resistor. The max current for 5 X 20mA = 100 mA, you can use a small everyday 2N2222 transistor rated for 800 mA. The TIP31C is a TO220 case, you don't need that. I am not saying 5 LEDs in series won't work, I am saying it is a poor design practice.

Just My Take
Ron