LED help

[legoman786]

i have this really cool looking red LED which i wanna put into my dell for a really cool light effect... but, i do not know how to even hook up the darn thing... i hooked it straight up to a button cell battery, nothing... HELP!!

[weirdguy]

What color is it? different LEDS use diffrent voltages.

[snefan]

i have this really cool looking red LED which i wanna put into my dell for a really cool light effect... but, i do not know how to even hook up the darn thing... i hooked it straight up to a button cell battery, nothing... HELP!!

i think that you missed that part :p

anyways, red LEDs use about 1,5V so you need a resistor to get the spare Voltage away

you could hook it up in a molex you aint using for any part of your comp, but dont know how exactly, i've never done it before either

btw are you familiar with Ohm's Law?

[Aero]

http://metku.net/index.html?sect=vie...calc/index_eng

^^ thats an "LED Calculator" enter in the voltage of the LED, voltage of power source (12 volts), and the current in mA. click "calculate"

[legoman786]

i dont know how much power the LED draws, and whats the Voltage Drop Across? how do i calculate how much mA -- I'm confused, I think I shouldnt even do this without knowing more about LEDs, sorry I took your time. Thanx anyway

[Malatory]

Oh you want to know about LED's

Points you to http://linear1.org/
Read though the LED center and then hit his LED Wiz..

But in a nut shell
typical LED draw from 1.5V to 3.7 depending on what type they are. And you would use that for the Voltage Drop (as it is taking that much power from the source)

also most LED I have come across use 20mA (There are some that use 10 or more) But again that is a good place to start.

using the 1.5 and 20mA is a good place to start. If it doesn't light up 1st try turning the LED around as DC power flows one way and a LED will light on only if the power is flowing the right direction.

[slaveofconvention]

i hooked it straight up to a button cell battery, nothing... HELP!!

Erm - if it was a 3v battery, and a 1.5v LED - all the advice in the world aint gonna help ya - you sure you didn't blow the LED?

[snefan]

the metku calculator says you need a 525 Ohm resistor, get one as close to that number as possible, one that is higher so you're on the safe side

and if you had read what i said you would have found out that red leds use about 1,5 volts and you would need about 20 to 30 milliamps

[Chapel]

I bet if you do a google search, you can find a nice tutorial for how to hook LEDs up to PS w/ or w/o a switch. Ill try to find one.

[legoman786]

wow, lots of help guys. now i can actually mod my PC, YAY!