Step 6: Building the circuit
Many people get scared when they see all those weird circuits with those symbols on it. Having no clue what they mean.
That's why I made a instructable friendly circuit image :) See photo 1.
1. Make sure you have all the materials to make the circuit. And enough electrical wires to connect all the components.
2. Before we build the circuit, we first need to put the audio cable through the whole in the back.
3. Build your circuit, and test it out. The best way to test it is through your audio output from your computer. Make sure the audio on your computer is set to 100% and then test it.
Circuit: The positive pole from the adapter goes to the positive leg of the first LED. Next the other 5 LED's follow. Hook the negative leg from the first LED to the positive leg of the second LED. Hook the negative leg from the second LED to the positive leg of the third LED, and so on. The negative LED from the last LED goes to the center pin of the TIP31.
Then hook the right pin of the TIP31 to the negative pole of the adapter.
All there's left now is to hook up the audio cable. Hook the red or the white wire from the audio cable on the left pin of the TIP31. And connect the ground wire from the audio cable to the right pin of the TIP31.
For better details please see photo 1, the circuit.
4. If your circuit works, solder all components together so the circuit stays together nice and strong and wont fall apart.
When done with these steps it's time to finish up!
If you have trouble getting the circuit to work, you can try to set it up first on a circuit board.
Carlosserious was so kind to make a how-to video on making the circuit, click here for the video.
That's why I made a instructable friendly circuit image :) See photo 1.
1. Make sure you have all the materials to make the circuit. And enough electrical wires to connect all the components.
2. Before we build the circuit, we first need to put the audio cable through the whole in the back.
3. Build your circuit, and test it out. The best way to test it is through your audio output from your computer. Make sure the audio on your computer is set to 100% and then test it.
Circuit: The positive pole from the adapter goes to the positive leg of the first LED. Next the other 5 LED's follow. Hook the negative leg from the first LED to the positive leg of the second LED. Hook the negative leg from the second LED to the positive leg of the third LED, and so on. The negative LED from the last LED goes to the center pin of the TIP31.
Then hook the right pin of the TIP31 to the negative pole of the adapter.
All there's left now is to hook up the audio cable. Hook the red or the white wire from the audio cable on the left pin of the TIP31. And connect the ground wire from the audio cable to the right pin of the TIP31.
For better details please see photo 1, the circuit.
4. If your circuit works, solder all components together so the circuit stays together nice and strong and wont fall apart.
When done with these steps it's time to finish up!
If you have trouble getting the circuit to work, you can try to set it up first on a circuit board.
Carlosserious was so kind to make a how-to video on making the circuit, click here for the video.
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Having one TIP31c
I followed this picture but instead of using a battery I just use my arduino Diecimila powered on the USB and one led without resistor, but when I put the right wire of the jack and the ground of the right wire on the TIP31C sometimes it just turn on and keep the light or nothing appear and then when I start the music nothing is there...
please some ideas????
http://k45.kn3.net/D49190D80.gif
So if you want to have 20mA through yr LED's you will need to input 1mA from yr microphone.
I am not sure all microphones will be able to deliver that current: modern microphones have an output voltage of perhaps 5 mVolt, but i am not sure how much current they will be able to deliver in a TIP31's base.
It won't hurt trying the circuit though :-)
If it does not work properly, you could use a BC547 to make a Darlington circuit with the TIP31 and use a proper base resistor for the BC547.
http://electronics.indianetzone.com/1/darlington_pair.htm
Or make a simple amplifier circuit with a BC547 (emmittor to ground, 10kResistor between Vcc and collector, 22k resistor between base and collector, 1 k resistor between base and signal. Lead the signal from the collector to the base of the TIP)
There is a solution though, as manas.g29 already suggests: a resistor. To calculate that you need to know the exact forward voltage of your LED's. If you do not know, check here: http://www.instructables.com/id/Determining-Forward-Voltages-of-LEDs/
Now suppose you come to a combined forward voltage of 10 volts and your battery is 12 Volts (beware, sometimes they can be 13, or 14) that means you have to 'get rid' of 2 volts.
Suppose that you have regular LED's (so no high power), these can take 20mA. So you will need a resistor of 2000/20 (2000mV/20mA)=100Ohm and it should have wattage of 2x2/100=0.04 Watt, most common resistors being 0.250W so that shld be ok
Now there is another problem. Since the LED's are in series and if they are not the same -especially if tey are of different color- They may have different forward voltages. That means that though the total forward voltage over all 4 LED's may be ok, one or more LED's may still have a Voltage and thus a current that is too high.
So if you are using different color LED's I would not put them in series, but parallel, each with their own series resistor. Ofcourse this means more power loss in the resistors, but that is better than blowing yr led's.
The best way would be to make a current driven circuit in which the current is maxed to say 20mA and varying with the audio input. That ofcourse requires a few more parts (but not really much more.
The enclosed picture gives an idea of how to do that. Ofcourse you do not need a FET, a powertransistor (like the TIP31 or a 2n3055) could be used as well
I have a switch that turns it from being on solid to turning to this circuit. Last night it was working just fine when I switched it over to the "music flash" circuit but today its just off when I do the switch... I did loads of test. probably 3 to 4 hours in between my classes to figure this out but just cant come up with any solution other than I must of blown the transistor. Any ideas why this might of happened? im using a 6volt battery source making me think this should not blow.
Im trying to implement this into my car, but not sure how to? Because this is using a 3.5mm audio jack to plug into your ipod or computer, so how would i do this in a car because there is nowhere to plug a 3.5mm jack?
So basically this wiring diagram is how i want it to be in my car, The top left box symbolises the music box (This circuit that makes the LEDs flash) and basically im having red green and blue LED strips in each footwell so thats why you see two of each colour, and each footwell has a 3 toggle switch so the person sitting there can choose the colour, and then the other switch at top left is going to be a 3 way switch so i can choose whether i want the music box on (so LEDs flash to music) or off (so LEDs just stay on, no flashing to music)
I am trying to understand how transistors works. I read this article http://www.satcure-focus.com/tutor/page4.htm.
But in the music led case wasn't supposed that base has to be connected to 3,5mm so that the music signal works like the plunger in the example which change the flow from baterry to leds????
why the music plug is in collector - emitter legs?????
base is the left leg i can see it now. Include the photo of tip31 to your instuctions it will make easier for beginners to understand
The second issue is the light stays solid when I play music. Not sure if the two problems have anything to do with each other. Any insight would be appreciated! Thanks!
The best thing you can do (if you're using a transformer like I am, 12v) if you're having this problem is to do your LEDs in parallel instead of in series. I just did this project and all it's running off of is a 12v transformer and so far I have 35 leds running in sync with the transistor perfectly and nice and bright. The other reason it's running bright for me is because I have it plugged into a main desktop computer, which I think is having some affect.
microphone->cheap stereo speaker sistem with amplifier->the scheme above, instead the 3.5 mm the wires from one speaker. Good luck and le me know if this works.
As a precaution keep the volume to minimum and then incease it slightly on the cheap speaker sistem.
sorry.. a newbie here.. :D
Can someone give me circuit for stereo music led box that works perfectly?
:)
I've tried to make the circuit in some different ways:
- 3 LEDs series with resistence connected in parallel (2 series only)
- 3 LEDs series withouth resistence connected in parallel (2 series only)
- single LED with resistence
- single LED withouth resistence
I use a 12V - 5A adaptor but in every case LEDs blink at very low light and very low rate, if i complete the circuit with my hands i can get a very higher light!
I've noticed the TIP31 i've used has written TIP31CO should be that? Should be anything else?
I'm not used with transistors... which feature i need to look at?
are they 5 mm LEDs, and what color? What did you figure the resistance for the circuit would be? And it's always best to have a resistor to limit the current or you could blow the light.
My new favorite calculator too for this is the series parallel array wizard at http://led.linear1.org/led.wiz
It should just work in series for a small project like this. The tip31 seems alright, just double check the connection to your transistor and your LEDs. I looked up the tip31 datasheet (since I want to make this too) and the Tip31C can take higher current and voltages is the only difference I see.
I used 5mm blue LED (high brightness, 20mA) they should be 3/3,3V but i'm not sure about this...
They gave me a 150 ohms resistor for each 3-LED series:
V=R*I=150ohm* 0,02A= 3V
But the attempts i made haven't change the results so i can't figure out why do i need a resistor! XD
Finally i suppose when i use my hands to make the circuit i'm the one with lower resistence so the current uses my body to connect and it bypasses the transistor and other stuffs
That attempt only allowed me to figure out LEDs were not broken and could make much more brightness
I'll try to make a video or some photo and then post them but i need time
I added a picture of a schematic, will this work like this?
1) Can I use the BD243B in order of the TIP31?
2) I want 2 series of leds in parallel. One serie for the left audio channel and one for the right. With the pot I want to regulate the reaction of the leds when I turn the volume up or down. Is the correct place for it like in the picture, or has there to be one in the "Audio left" and "Audio right" line?
3) I also want to add a switch, to turn the LED's on without the audio-option. Where do I have to place it then?
Thanks in advance, and sorry for my bad english ;) I'm from Belgium.
your power source goes to one side of the switch, and the other side of your switch goes to your + sign in your drawing. The - sign or neutral stays where it's at right now. hope that makes sense.
Your battery is backwards ;)
You will need to know the following about the LEDs you are using- the voltage drop across them and the maximum current they will take. Then you should work out the voltage drop across a single chain of diodes by adding up the voltage drop for each diode. You want to end up with a voltage drop near the voltage of the battery so you are not wasting too much power in the resistors, but low enough to make sure you get good brightness as the battery voltage drops. A couple of volts difference should be fine. It also depends to some extent on how much voltage is dropped across the transistor when it's fully driven, but these calculations should be okish.
For example, if each diode has a voltage drop of 2.1 volts, three in series will have a voltage drop of 6.3 volts. This means that you would need to lose 9v-6.3v = 2.7volts in a dropper resistor. Then, using ohm's Law, you can work out the resistor value from the rated current of the diodes and this voltage drop. So for a LED current of 25mA (0.025A):
V=iR So 2.7=0.025xR
Rearranging:
R=2.7 / 0.025 =108 ohms.
So a dropper resistor of 100ohms in each chain should be ok.
In reality, using a battery, the battery will limit the current and you'll get away with smaller value resistors, 47ohms or so. However, if you are using a proper power supply, you'll need to measure the supply voltage and not trust the label, unregulated are often much higher than the stated voltage.
Fortunately you don't need to work this out yourself, you can work out the value of the dropper resistors needed here:
http://led.linear1.org/led.wiz
I haven't measured the voltage drop across the LEDs yet, but I'm pretty sure it's about 3v. The problem is that I don't know if a USB can provide enough current. I read that they only have up to 180mA but if I use 25mA across each LED I would need a total of 500mA wouldn't I (I'm using 20 LEDs)? Can I use a lower current to power the LEDs? Supposedly this guy used 36 LEDs powered by 5v USB. Could you help me clear some of this up? Thanks
http://en.wikipedia.org/wiki/Universal_Serial_Bus
a USB 2.0 port can provide up to 500mA so you should be OK. LEDs are pretty linear with light output although they are slightly more efficient at lower currents, so if you provide less current it will provide less light, but slightly more than it would if it was truly linear. This means also that once the current limit has been reached, putting in more LEDs will make each LED slightly darker but overall you should get a little bit more light out due to inceased individual LED efficiency. However, it probably won't make any great visible difference and the only advantage of using slightly more LEDs is they will last longer and have less tendency to blow on over current.
I would still use a current limiting resistor as the USB voltage is supposed to be 4.4–5.25 V even though the USB connector is probably current limited itself. At 500mA with 3v LEDs, this would need to be a 3.3 or 4.7ohm 1W resistor.
I have also had issues in the past with USB connectors polling and lights connected to them flashing on and off, but I think that is either computer or OS related. If that's a problem, you could get over it either by a software fix or by using a seperate USB PSU.
want to ask about jack audio. If i connect directly to my PC or mobile phone,
it will work or need speaker?
There are lots of cicuits on the web showing how to use another transistor in front of the transistor like a preamp but I think that's just complicating it for you. The above should work fine.
I would also put in a current limiting resistor in the LED line, maybe 33 or 47ohms (see my other comments) to be on the safe side.
You will need to have a much more complicated circuit like this one using a triac or scr:
http://www.simplecircuitdiagram.com/2010/05/20/musicsound-controlled-disco-light/
BUT- it sounds from your question that you don't yet know enough to attempt this and playing with mains voltages can have health consequences of a the kind involving a coroner.
I know I can test it or so on, but I don't want to risk cause I'm preparing a big project in my car and I don't want to blow out any LED's or TIP or even potentiometer which is pretty expensive ;]
After that, you might need to put in a preset or a pot to control the light effect relative to the car system. I'd use a 4k7 pot with the outer pins connected to the speaker and earth and the wiper going to the transistor.
I'd also put some current limiting dropper resistors in the diode chains, given the variations in battery voltages and the potential for a car system to delivery very high currents. I'd also put a suitable fuse in line with this just in case. See my reply above and you can work out the value of the dropper resistors needed here:
http://led.linear1.org/led.wiz
Good luck.
Good luck and I hope this helps.
I used
a 12V DC adapter,
4 blue leds
1 Tip31C transistor
1 audion jack from my old headphone
I connected the jack to my laptop audio output hole.
But all went in vain.
Would any one please kindly help me out ????
1)lets say i have a song on my ipod, and when i listen with my skull candy headphones some parts of the song are dedicated to one speaker or an other, will this effect the light show id we're only using a left or right wire? or can i just connect both to the same leg of the transistor? or would a normal 2 wire lead solve this problem?
2) can i also connect a small car speaker such as this (http://www.gemalta.com/ds/90_2000.htm) or this woofer (http://www.gemalta.com/ds/90_0135.htm) and connect the leads directly to the red and yellow wires in the circuit? would i need an other power source or resistors ar an amp for this? Or would just connecting this circuit (http://www.instructables.com/id/Simple-Stereo-Amplifier/#step1) to the red and yellow wires save me time?
3) if i put 4 more LEDs in parallel to the current 4 LEDs, would this cause the LEDs to shine dimmer? or would it make no difference?
thanks in advanced for the answers!! I really appreciate it :D
2. You need an amp to be able to run that large a speaker
3. Makes no diffrence
Hope I helped!
Light and sound are waves. so you see light waves and hear sound waves. This transistor converts ur sound waves to light waves so your basically seeing sounds through ur LED lights instead of hearing them if that makes sense. now because u have plugged ur LED box in as ur output device. u get no sound. so use a STEREO splitter which allows u to insert 2 output devices into the single slot of your hole or w/e so this includes laptop and ipods. this allows you to have both sound and light waves of the song without missing out on certain parts because it gets played through a certain headphone. so yeah hope i helped. good luck bro
First of all, please try and use proper english. There is no excuse to use u and ur when typing on a computer. Also, the transistor takes the sound waves represented as electrical fluctuations in the wire and uses them to turn power to the LED's on and off. So, at the end of the day, you get to see the sound waves. not as fluctuations in current in a wire but as fluctuations in the ammount of light emmitted.
Now for the original question posed.
1) yes, if you listen to bohemian rhapsody for example, little high and little low are on the right and left channels respectively. so if you assemble this circuit and use the left channel you will get pulsing on little low but not little high. To correct for this you could add a tiny bit of circuitry to combine the left and right channels into a mono channel. attached is the circuit i speak of. It is very simple to implement and if you use a ganged potentiometer instead of the two resistors you can even adjust the "sensitivity" of your light box. simply connect the 3.5mm TRS connector to the mixer, the out to the leg labeled "left or right" and the ground to ground.
2) not exactly, depending on your amp setup(bridged, bipolar power, etc.), you may not be able to do this safely. I would reccommend using a line level output because the current that can be supplied by a car amp can easily fry these electronics
3) from an electrical standpoint, i see no problem with putting the LED's in parallel, the only thing to watch out for is that this will double the load on your power supply because the resistance of the LED's will appear to be half as much in parallel. Since your LED's draw their power from the transistor, you might have to beef it up a bit. Alternatively, you could just build two circuits for each strip of lights you want to use.
Feel free to play with values and parts to see if you can get the circuit to behave for your specific application, after all, that's what DIY is all about
I have a questions, I have read a lot of these comments but I am still a little unclear about why I can't gt my lights to dance when its all connected to my laptop. I am using a TIP31 transistor and a 12v ac adapter, I have 4 LEDs and they light very good with plunged inn to the computer, but they don't blink or dance, what should I do??
Thanks for the help:)
I don't know what circuit component gates frequencies in audio. After ripping apart a couple of speakers I saw that they use capacitors to make similar speakers out put only certain freqs. For instance my subwoofer has two sub-speakers. Both are identical but the top most one has a .6 farad (i believe, im waiting for class to start so I dont have it front of me) cap on one of the leads. This speaker outputs freqs around 100 - 200hz while the bottoms speaker without the cap goes even lower and is able to react to freqs lower that 20hz.
From this I'm guessing you can split the audio cable into 3 sets, each one can have a cap of different ratings (This is where I have a huge black hole cause I don't know what rating is for which set of freqs) and then the out put from each cap will have its own transistor to switch the lights on and off.
1 / (2 * Pi * f * C)
So say you had an audio signal at 1kHz, with a typical 100 microfarad cap:
1 / (2 * Pi * 1000 * 100uF) = 1 / 0.628 = 1.59 Ohms
So if the signal was at 3V, and your speaker was 8 ohms you would have a current of 3V / (1.59 + 8) = 0.312 or 312 mA.
My point being that capacitors can act as a high pass filter and take out the bass frequencies, because a lower frequency sound will make the effective resistance go up and you'll get less power to your speaker. They can't on the other hand be made to filter out high frequencies, for that you need something called a low pass filter. They can be made from just 2 components though, so it may be worth looking into if you are interested.
I did this last year in lab and currently am redesigning this project to account for filtering. use google and wiki to search this info... with a little patience and creativity you can have multiple LED boxes tied tied to audio output
I know it can be louder I just dont know how :P
I've tried to set u a higher voltage but it doesn't make it brighter I think an otther transistor than tip31c
Thank you for the great tutorial, it works perfectly!
However; would it be possible to add an Op Amp between the audio source and the circuit? Because it only works when my audio output is at full blast, and the LED isn't as shiny as it could be in a simple circuit.
Dou you think that this system could be combined with a microphone (being the audio source)? Hence using an op amp because a microphone signal is very low right?
Final question: what is the voltage range the tip31can be used?
Thanks
Sorry for the mistakes, english isn't my maternal language :)
Thanks in advance ,
Mitch :D
I am using an assembly of 8 AA's for 12V instead of an outlet. Something weird about my circuit is that when I tested to see if the transistor was at fault, I connected the circuit directly to the battery assembly and they lit up momentarily before being fried. Maybe my LEDs are lower voltage? I don't see why; they are standard LEDs I got in an assorted bag from Radioshack.
But that's not even the main problem. The lights do not even get to burn out when I have the transistor in the circuit. I know I wired it properly. I tried two different ones of the same model number. Got them at the Shack too. The package simply says "TIP31" and does not specify a letter after, but on the transistor itself is printed "TIP31AG." Maybe that is why it doesn't work?
Any help would greatly be appreciated.
4 LEDs, white: 3 Volt each = 12 V .. this setup is fine
(yes, yes.. I know.. on the package of the LED it might say Vf=3.3V... BUT.. as soon as they become just a bit warm, Vf drops.. to about 3.0 to 3.1 V).
The point is, runnig 4 white, blue or green LEDs in series from 12V is OK, as long as the supply is stable!! If your "wall wart" transformer power supply hands out 12.5 V or more... they will overheat and not last long.
Other LED colors:
4 LEDs, red: 2.2 Volt each = 8.8 V .. If you drive these 4 LEDs directly from the 12V battery or power supply, just as the original diagram suggests, without a resistor, then they WILL go dead very soon.
To avoid these pitfalls, you can add a resistor in line (in series) with the LEDs. That resistor should be about 180 Ohms for red, about 150 Ohms for yellow or amber LEDs, and about 47 Ohms for white, blue, pink and green LEDs.
I no idear what I can not upload the schmatic ,so...
if even not working , you can add capacitance (about 10,000p) between transistor B point & signal input (audio outlet)
tip31 pin configuration
http://www.alldatasheet.com/view.jsp?Searchword=TIP31
Do you mind if I bombard you with questions? :P
What's the logic behind adding a resistance?
How come the range is so large (4.7k to 47k)?
Was that meant towards my 8-battery assembly? Or should it have had the same effect with two batteries and one LED?
Thanks for your help btw :)
you are welcome, I can answer any question about electric.
add resistanct can help the transistor working.
range so large. because the audio outlet volume & the circuit total load( min R to get much power ; max R to get a litter power)
series 8-battery you can get DC 12V,use DC12V can help you easy to work but careful you must series 4~8 LED(you can series 8-led ,if it not work or dark then to decrease LED .it is safe way)
Because when I tried my iPod, nothing happend. When I hooked it up to the audio of my computer, it worked like a charm! If you test it on your computer, don't forget to put the output audio on 100%.
but as i put it in my computer, it works
can i do somewhat to let the leds works with my ipod?
srry for my enlish
please send an e-mail to: jelle.langedijk@hotmail.com
If you can, snap a photo.
Thanks SoundTechie, motadacruz, smithlee, and everyone else who helped. I appreciate it a lot!
You've got 4 batteries in series that give you 4x 1,5v, so thats 6v total.
In your LED series you've got 4 LED's that need 3v each, so a total of 12v is needed there. You do not have enough power there.
Just test your circuit with 1 LED and 2x AA battery. This should give 3v from to battery to the 3v LED. This should work.
If this works, you can put the LED's parallel instead of in series.
@Spurr, I don't think I burnt them out. After my testing my first 4 LEDs and them not working, I connected the series directly to the battery w/o the transistor, and then the LEDs burnt out. So I swapped all the LEDs, which I tested on another device beforehand. So they aren't the problem either.
I'll try a parallel circuit later when I get home and let you know how it goes.
Try switching some of those audio wires about and see what you come up with.
If that doesn't work, and you have a voltmeter, see if you're getting power out of the TIP. The next thing I'd try is just using one LED in the circuit (with a resistor) and see what you come up with.
I made a video to try and help everyone out. It might be useful.
http://www.youtube.com/watch?v=1TUYNuh-iqQ
I've tried three different audio jack/cables, two different TIPs, and several LEDs. I tested the single LED on my two-battery assembly without the TIP and it lit up nicely. And after all this, I'm completely baffled.
Same here dude, baffled.
Just typing some checks here just in case:
- Is the PC master volume on 100% ? (Not the speakers itself, but the PC master volume)
- There is a guy with comments on this page that tried 1 PC and nothing happend, tried a different PC and it worked like a charm. Problems with a crappy soundcard or something. Can you maybe try a different PC ?
Hope we can figure it out for you dude!
try again but with an extra light, that is what i am going to do and i seem to have the same problem
try pulling it out if there is any
make sure you make a good connection
thats just my guess hope it helps
THX
for example, I'm planning to run the LED's parallel so that they all get the voltage equally, rather than having the voltage split up. Can anyone show me a simple diagram of how to do the same, but with the entire setup instead? please, and thanks. email would be nice, jelly.turf@gmail.com
i come from belgium srry fio my bad inglish
i have a 3V wall adapter and i want to have the circuit from step 6 run in parallel with the same step 6 circuit .
i'm planning on having the left component of the music go with one circuit, and the right component run with the other. get what i mean?
the 3V wall adapter btw is from my gameboy color. it came in handy after all, i mean, what's the use in having a portable game system WITH a limited range of mobility?
anyway, thanks for the help.
reference below schmatic.
sry for the trouble!!
Adjust VR can change working point, that can controll LED bright or dark.
Different audio sourse have different FAN OUT level,you can adjust VR to fine LED working for different audio sourse.
what is VR? and where do add it?(i mean betwn what) can you mail me a schmatic (the one u are talking about )at aafaquehs@yahoo.com....
http://en.wikipedia.org/wiki/Trimmer_(electronics)
The output barely lightens up a single LED or 2 if I connect them in parallel...
maybe your POWER SOURCE is too low.
do'nt parallel LED,because each LED consume difference,so you parallel LED maybe result difference bright each other.
thanx for ur help!!!
Adjust VR can change transistor WORKING POINT,that can help you LED bright.
thanks for your help ! :)
Could someone draw the layout ... how it would be on a bread board.
Who ever does it will receive 10p through paypal for their time :D .... seriously ... if you want ill drop you 10p
You have 10 mins from NOW. :D
Should get you exactly where you need to be.
I got TIP 31 C....is that the problem and is it different for TIP 31?
thanx....
and you can use one resistor (about 4.7k) pull HI (between transistor B pin & +v .) or pull LOW (between transistor B pin & -v .)
try these way you can get you want
Thanks
when the instructions say left or right does that mean it is optional on which one you attach? do you, or could you, do both left and right?
If you go with the second option using two TIPs, try something like one using a TIP31 and the other a TIP42. You should get a neat result.
In any case near perfect instructable great job,
thanks
its because if you leave one of those sides alone u can use it in a speaker and instead of buying a double audio jack to put in the speakers u put in the peaker inside the box :D but i want to know if that is possible
Also, don't forget that LEDs are Polarized. IIRC the flat side is negative.
So, if I wanted to add this type of flashing lights to the stereo system in my car, and wanted to have a bank lights for the right side and a separate bank of lights for the left side, I assume it would require the use of at least two TIP31's. Would this require putting the TIP31 before the speaker and before the LED's? As there are two wires on a speaker, what wire gets connected to the TIP31?
Thanks.
Unless you are trying to use the speaker wire to power it, I'm guessing you would just take the transistor and connect your power source the same way as this box. Then you take either side of the speaker wire, since it doesn't really matter as both are a part of the power to that speaker, and connect that to the pin the 'ible says here.
Then you'd just do it for every speaker you want to turn a bank on.
New to this site and I love this stuff...thanks for the info.
Basic Stereo Speaker Crossover Inductor calculator.
It uses Inductors instead of a cap/resistor combo for the filtering.
5/5
Cheers
replace battery with 120VAC to 12 VDC power supply
second, you need two of these, one for left and one for right, or split the led's so half fire off left and the other the right
Jake's basically right. A mono speaker plug reads the right channel from a stereo speaker jack, and sound engineers know this.
Neat project!
So you have your plug. And only one of the two (left or right) should be connected to the TIP31, the other one should simply be cut off.
then the ground goes on another leg of the TIP31 and on that same leg the minus cable of the battery. And on the third leg the wire that goes to the led's and ultimatly the + of the battery.
That's how I understand it. But what I'm really wondering is about the right and left plug. Won't it make a difference when the music plays when the lights light up? Perhaps a stupid question but my electronic knowledge never got to sound ;)
If I am not mistaken, you should be able to combine left and right and run them as one for a combined signal. Or, could also choose to do 2 sets of lights, one for each channel.
I guess if you broke the signal down with enough filters for different frequencies you could make a pretty cool visual equalizer this way.
How would you achieve the stacked up look?
As in columns of led's with more led's light up as the signal increases rather than having all of the led's glow stronger. that would be a nice thing to make
That's a complete guess though.
And, you could leave them exposed on the back to change their values if you so desired later.
I'd probably try to do 3-4 separate values. One for sub bass, cutting off at 80-100Hz, then something for the remaining bass from 81(-101)-250k (preference of when to cut it off is up to you) then go from there for midrange and treble.
Here's a good breakdown of the frequency ranges:
Freq ranges
I am not sure, but seems like I've read that you'd need some caps in there too to help do cutoff if you wanted only the range of frequencies (bass only, mid only, treble only) for that light? Can someone clarify or correct this?
however running a combined signal sounds interesting.
And I think the author made this a mono one because I believe he said it a few comments lower.