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