Simple Cheap USB LED Light

This is my first Instructable so I thought I'd start with something simple.

For this project you will need:

1 - Male USB plug (got mine from a $1.50 Wii Intercooler)
1 - 22 ohm resistor (red-red-black) thats all I had, dunno if its perfect
1 - LED
Soldering/Desoldering Iron
Solder
Hot glue (optional)

Sorry about the bad pics

***NOTICE***
If you do anything wrong and screw up your computer, burn your finger etc etc...I'm not responsible!
It's a very easy project, but things could go wrong,

Step 1 Extract the USB plug

Open the Intercooler (or other sacrifice) and locate the male USB plug...not to hard. Next desolder the USB plug from the board. I pulled out the middle 2 tabs because those are for data.

Comments

[junits15]

why in the world would they make an intocooler for wii? it barley gets warm

[microchip55]

actually it makes the discs HOT

[ODST.Tainted]

being a pro wii player.. and also gamecube (cooling system is just as efficient) and not liking to save and turn off while i sleep/work/do projects i noticed after about a week my gamecube got warm and the game got retardedly hot (i've yet to do this with my wii because i love it so much <3) which leads me to believe the wii can do the same thing . of course this is just me putting two and two together to try to come up with the most logical answer to your question so dont hold me to it

 

[jaxxster1]

i am using a 10 Ohm resistor and it WAS going for 5 housrs until it started to smoke and burn out...... oops!

[Berserk87]

a usb port supplys 50mA max, and led can take 28mA max normally.
with your 22 Ohm resistor that led is getting the full 50mA (and more if it can get it).

your going to be burning your led out.... =\

you should be using a 200 Ohm resistor minimum (25mA) , you could be using a 500 Ohm resistor if you want (10mA).

if your using a ultra bright led (the clear ones) there still blindingly bright at 7mA. (700 Ohm resistor).

[zaketus]

How are you making your calculations? Because they are not correct. You are calculating the current through resistor connected to 5V (USB-port in this case), without anything else in series. You are right, 22ohm resistors is to small.

You are using U = R/I -> R = U*I, but you are using wrong U. U isn't voltage drop of the whole circuit, nor it's the supply voltage (witch is voltage drop of the whole circuit :P), but in this case it's voltage drop over the resistor. In this case power supply is 5 volts, voltage drop over led is something like 1.6-2.2V (it can be something else, but these are common voltage drops of red LEDs) that makes voltage drop over the resistor: 5V - 2.2V = 2.8V. Now this is the U we are going to use in R = U*I formula, when calculating the value of the resistor.

Lets say voltage drop over the led is 2.2V and we want 15mA : R = (5V-2.2V)/15mA = 2.8V/0.015A = about 187ohm.

[Chicken2209]

been done... but they made their usb from scratch

[lemonie]

It may be simple, it may your first Instructable, but those are some good images. Taking close-up shots often defeats people. (What camera?) L

[ju1c3d]

Thank you, the camera is a Panasonic Lumix DMC-TZ5 (got it at Costco)

[lemonie]

Thanks for the reply - It's a nicely composed Instructable, which goes to show that "first" doesn't have to be poor. L