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USB led light

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Step 1Materials

USB plug and cord
Blue LED (any other color will work too)
100 ohm resistor
Case or housing to hold the led ( I used a cheap mini keychain flashlight housing)

Tools Needed to do this project

Soldering iron
Solder
Pliers
Screwdriver to take apart case

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34 comments

Nov 18, 2011. 4:22 AMG.one says:

i also have a USB cable but in that there is no output from black wire so connected to the green wire and by using a multimeter it shows 5v and i connect LEDs to it without using resistor my PC is showing that the USB device is not recognizable please help me
and i can't afford another USB cable

Aug 29, 2011. 8:38 PMmarkee2 says:

Tnx for info. I have the schematic of the LED light , might help if you planning to modify the circuit depending on your available materials
copied from
http://www.simple-electronics.com/2011/08/usb-led-lights.html

Apr 21, 2008. 5:41 PMbilal.a says:

thanks so much, but what i would like to know is, the voltage of the usb for multiple LEDS, can some one help me plz, and email me on mr_ucantcme@hotmail.com

Aug 17, 2011. 9:28 AMnodoubtman says:

Go there : http://www.ledcalc.com/#calc

Good luck! :)

Aug 17, 2011. 9:24 AMnodoubtman says:

Hello! To power up a blue light which is (2.5V), you have to put a resistor of 125 Ω, because if you put a resistor of 100 Ω, you will burn out your blue led. here's the formula : (Vc - Vf) / 20mA (1 led) *1000 = 125 Ω. If you put up a resistor size of 100 Ω : ((5 - 2.5) / 100 Ω) * 1000 = 25 mA, a single led is 20 mA, so your will burn out your LED.

thank you!
:)

Jul 2, 2011. 7:10 AMamitesh.chanda says:

nice one

Jul 2, 2011. 8:14 AMstevie1 (author) says:

thanks!

Jul 8, 2010. 9:40 PMahmad2117 says:

were do you get those male usb plugs i only find female

Mar 11, 2010. 4:58 PMnbagf says:

windrago its called auto hot key. google it

Jun 16, 2010. 8:26 AMwindrago says:

awesome thanks!

Feb 10, 2010. 9:01 AMwindrago says:

is possible to turn the light on/off through software?
I mean writing an app in C# for example.

Jun 15, 2010. 11:35 PMForenceKiller says:

You can do it...just disable that specific usb port...most modern languages support it, even script languages...

Nov 20, 2009. 12:40 AMdawsonj says:

ha in the first picture the light looks like a sad face : (

Nov 22, 2009. 11:48 AMstevie1 (author) says:

haha it does too!!

Nov 2, 2009. 7:22 PMdna24 says:

so would this work if i tried to plug it up to my cell phone?

Jun 18, 2008. 8:22 PMJahoovi says:

heck looks like u bought it

Aug 4, 2008. 1:26 PMstevie1 (author) says:

thanks

Nov 26, 2008. 2:08 PMColonel88 says:

EVEN BETTER. Make a flexi neck onto the thing and you have something slightly better.

Jul 7, 2009. 8:59 AMstevie1 (author) says:

one of my parents friends fly's for air Canada and goes to hong kong and gets us all sorts of junk. he bough me a usb fan with a flex neck but when i plugged it in to the computer it said it was using to much current so i ripped off the fan motor and put four white leds on it. it works really well.

Mar 24, 2009. 9:17 AMcrayzclown1 says:

would it work if i hooked the LED straight to the wire?

May 19, 2009. 7:12 PMteam_nes_1986 says:

Technically, it should work without the resistor, but one can never be too safe. From my own experience with LEDs and USB cables, the resistor also helps reduce the heat emitted by the current flowing through the circuit.

Dec 26, 2008. 8:12 PMpolonium9 says:

i made this with no soldering and it works amazingly BRIGHT DOLLAR STORE LED from a little light up car WORKS GREAT and to all who read this TRY IT you will be amazed I AM USING IT RIGHT NOW

Mar 9, 2008. 7:33 PMrakol1 says:

i cant find leds anywhere and im looking for one so i can make a keyboard light

Jul 31, 2008. 2:55 PMjgeekw says:

try radio shack. they should have drawers of electrical components

Mar 10, 2008. 12:02 PMstevie1 (author) says:

try "the source" by circuit city. i'm not sure if they have "the source" in the us tho(if thats where u live)

Apr 27, 2009. 9:33 PMpoop11346 says:

circuit city is gone from us I think but they have radio shack its cheaper to buy stuff in radioshack though (im from canada)

Jul 7, 2009. 9:01 AMstevie1 (author) says:

ya our radio shack went out of buisness when i was like 4. so now i have to eithe buy stuff from the internet or go get ripped off at the source.

Apr 21, 2008. 7:15 PMbilal.a says:

where can i get a USB cord and plug from, if i use a printer usb cord, but remove the end that connects to the printer will it work?

May 7, 2008. 5:50 AMawkrin says:

sure it will. I took one from the wireless human interface(keyboard, mouse etc) receiver and it worked

Apr 21, 2008. 7:39 PMbilal.a says:

sorry about all the questions_{, does the USB cord and plug need to be a sereis a or b? or could it be any type of USB cord and plug, please and thank you again}

Apr 24, 2008. 2:11 PMstevie1 (author) says:

a is the type thet plugs directly into the computer

Mar 10, 2008. 8:06 PMarnoldt says:

Does it matter on the strength of the led?

Mar 11, 2008. 4:05 AMstevie1 (author) says:

i'm not sure but i just used a blue led from "the source" but i'm not sure of the strength.

Mar 9, 2008. 4:38 PMGorillazMiko says:

Great job! Extremely easy to do, great pictures, very small, and not as hard as all the other ones. Great job once again, parts are easy to get, very cheap, I just might do this soon.