USB Led Light

by ranger_steve

45K4331

Intro: USB Led Light

USB led light

STEP 1: Materials

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

STEP 2: Assembly

Open keychain flashlight housing and remove all components. Solder positive wire of USB plug to the positive of the LED, solder the negative lead to the 100 ohm resistor, and solder the other end of the resistor to the negative of the LED. Install components in case.

STEP 3: Test It

Connect to a working USB port and it should light up. :)

32 Comments

G.one 12 years ago

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

bilal.a 16 years ago

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

nodoubtman 12 years ago

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

Good luck! :)

nodoubtman 12 years ago

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!
:)

ahmad2117 13 years ago

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

nbagf 14 years ago

 windrago its called auto hot key. google it

windrago 14 years ago

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

ForenceKiller 13 years ago

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

dna24 14 years ago

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

rakol1 16 years ago

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

ranger_steve 16 years ago

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

poop11346 15 years ago

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

ranger_steve 14 years ago

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.

jgeekw 15 years ago

try radio shack. they should have drawers of electrical components

Jahoovi 15 years ago

heck looks like u bought it
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