How a USB Works: The inside of the cable

Hi all, My name is Dexter, I am 15 years of age and this is my first instructable. It will show you the inside of the USB cable. And will show you how to connect a light to it. NOTE: Do not directly connect an LED to a USB cable, use a resistor. I appologise for the poor quality of the photos.

Step 1 Strip one end of the USB cable

Strip an end of the USB cable, remember to leave a USB port on one end, show the wires inside (with their coloured covers). The wires should be the same as in the photo below, the red wire = 5 Volts (+) and the black wire is the ground (-), for now ignore the other two wires I will hopefully make an instructable about them at a later stage. We will only use the black and red wires for now.

Comments

[Flying_MashedPotatoes]

yet you dont tell us what resistor to use... not even a link to where they say what rated resistor for what voltage of LED.

[Void Schism]

Just use Ohm's Law V = IR
or R = V/I = 5/20e-3 (for 20mA diode)
so 250 Ohms
Seeing as electronics isn't an exact science use a 220 Ohm resistor or try using combinations of resistors. Don't be afraid of a little trial and error :)

[llamma1010]

 My cable is slightly different i have a lot of thin exposed metal wire along with ones you have the red is + the black is - and the exposed wires are ground

[godofal]

thats just another ground

[iabler124]

Actually those wires are there to protect the Black, Red, White, and Green wires.

[godofal]

i thought it was connected to the metal casing of the USB connector?

[Dream Dragon]

A late addition to the conversation and hopefully you have already found the answer to your question, but for people finding this thread from a search, the exposed metal wire sounds like "Shielding". It is intended to reduce interference from other signals close by and should not normally be used as a "ground", or "return", though in some cases it may go to "Earth" which is NOT the same.

[godofal]

late, but not unread ;)
nice info, ty

[Hanashimaru]

Thanks! This instructable actually cleared things up for me =D

[324506allas]

thank you I am only 12 and this me a lot

[ManyuX95]

I don't know why people post their age, and I didn't understood what you said :)

[neil maclennan]

why so much negativity?

[ManyuX95]

It is not negativism, it is just that, it seems dumb to do it.

[dombeef]

"and this me a lot" Huh? And i guess that they are saying that they are young and foolish?

[SterLuMan]

i think thats just a simple christmas light or a little light from a toy... and a great tutorial...

[littlegandhi1199]

Hi i'm 14 years old and.. I already knew that , also like a million other people have been doing that as in connecting lights but what i am looking for right now is how to use the other green and white wires for your use

[zack247]

too bad you need a microcontroller...

[Herminator]

is your name really Dexter, lol i love that show :D

[JBizzle]

thats pretty cool. I dont believe I've ever seen inside a USB cable. lol
thanx =]

[Colonel88]

THE cable part was cool but the light not so much.

[railpressureflip]

Wow its pritty cool to see such a young boy with electronics knowledge. Good one =)

[gamer]

Second sentence ("It will how you the inside of the USB cable. ") doesn't make any sense, but other than that, cool! After reading that sentence for the 10th time, I realized that you probably meant "It will show you the inside of the USB cable".
Thanks for posting

-gamer