Instructables
loading
loading
Picture of musical beat thief
No we're not stealing musical beats of any kind but we are going to make leds flash to music using a joule thief circuit with a slight modifacation
 
Remove these adsRemove these ads by Signing Up

Step 1: Finding parts

Picture of finding parts
you could buy parts or salvage them like I did , but anyways you need :

toroid bead
3.5mm audio jack
thin wire
led (any colour)
270 ohms resistor (red,violet,brown,gold)
s9014 transistor or equivalent
stripboard (optional)

( http://www.datasheetcatalog.org/datasheet/auk/STS9014.pdf ) datasheet for the transistor.

Step 2: Construction

Picture of construction
DSC03198.JPG
DSC03199.JPG
DSC03200.JPG
DSC03205.JPG
DSC03214.JPG
DSC03215.JPG
DSC03228.JPG
First off I would start with the toroid you need really thin wire with quite thin insulation, you want about 9-11 wraps around the toroid bead. After that you should solder two different wires from opposing ends together, so now you should have 3 wires coming out of the bead the two you just soldered are now the + in wires,now take one of the remaining wires and solder the resistor to it then solder the resistor to the middle pin of the transistor , take the last wire from the toroid and solder it to the collector of the transistor.

Solder the + leg of the led to the collector on the transistor and the - leg to the emitter.

Also add a length of wire to the - leg of the led for the ground wire.

Then solder the ground wire to the 3.5mm jack and the positive to the left or right channel.
jacob56805 years ago
 I think I blew up my transistor while soldering ( way to hot ) and the transistor is actually emitting sound... O_O I can hear the beats of my music from the transistor

frag_bomb (author)  jacob56805 years ago
you should deffiently put that on youtube =D
 
Fixed the problem by reversing the resistor and ground. :P
zoltzerino6 years ago
would a bc108 c work??? ZZZZ
frag_bomb (author)  zoltzerino6 years ago
see no reason why not, try it
I have just made the 'standard' JT I have no resistor before the base and I am using a bc108c. It only works with AAAs not AAs it just flickers with AAs. Current overpowering tran??? ZZZZ
frag_bomb (author)  zoltzerino6 years ago
try it with a resistor you need it to determine the current output of the transistor ....... i think
I made a MBT and it works, I even split the audio so i can listen and flash! Although it only flashes at a painfully high volume, is it my bc108 (do I need a low voltage transistor) or have I got the wrong amount of turns on my toroid??
frag_bomb (author)  zoltzerino6 years ago
Well done on making it, i think a lower voltage transistor would be best you want a lower emitter - base voltage to get it to flash at lower volume.
ok thanks
Biotele6 years ago
can you post a video of the LED flashing to the music?
frollard6 years ago
The solder DID ruin the photo - the camera focused on the solder instead of the project! ....USE MACRO MODE FOR CLOSEUP PHOTOS!!! :D If you don't have macro mode, then since its gonna get sized down by instructables, then take a picture, in focus, from farther away - then crop it. Pictures aside - neat project! Extremely low lowpass filter :D
Kokkan frollard6 years ago
We have a photographer in here RESPECT
Restecpt. Ali G... IN DA HOWS!
ironsmiter6 years ago
hmm. I wonder if anyone knows(or knows how to calculate) the resistor value to put one of these IN-LINE with a headphone speaker. I'm thinking a nice blue led synced with the music on my headphones. I get music, and the people around me get a light show!
Emsaid6 years ago
the solder didnt ruin anything... ...the picture already was ruined! (Just kidding!!) Very cool!
hominid6 years ago
Very good and clear. I like the new use for the JT. Thanks.