|-- LED Replacment
-- Price: ~ $2.12 ea USD
-- By: GideonX
-- Page: 1 2
With neons, cold cathode and EL lights making their rounds in cases,
we probably overlook the cheapest and easiest lights to use, LEDs.
Light emitting diodes (LEDs) are about as common as screws in
everyday life. They are in a lot of electronics we use and
they provide visual help in all sorts of environments.
So how do these tiny
workers exactly funtion? You can think of them as just tiny light
bulbs, but without a filament. Because there is no filament to
warm up, LEDs are less prone to burning out and emit very little
heat. The actual light emitted is caused by electrons moving
rapidly. For more information on the history and a more scientific
explanation, check out LED
Museum. There's a ton of information there of LEDs past and
What I have here is a 5mm, 3.7V, 3200mcd (millicandelas)
blue LED (thanks brutal!). The mcd rating is just a brightness
rating, the higher it is the brighter your LED will be. On most
LEDs you buy, there are leads that come out from under the plastic
dome. One end would always be longer which tells you that it's the
anode (+). The shorter one is the cathode (-), this helps in
wiring up your lights correctly.
Before we go ahead and start replacing
LEDs all over the place, I'm going to setup a quick test station for my
LEDs. Here's what you need:
Any HDD plug from a case
LEDs (blue is always nice, but more expensive)
100ohm, 1/2W resistor
Soldering iron (optional)
I ripped this plug off a old case, any
of these holders will work. I prefer the two pin variety since
I can just plug the LED in directly, we'll get to that in a bit.
When you get a hold of a molex
connector, you want to make sure you are using the 5V line (red).
I had this extra molex with a yellow wire, so I just flipped it
around and put it into the 5V line. Confused yet? : )
If you want to use the 12V line, you're going to
need a different resistor (~300ohm) or so to prevent your LED from
exploding. I'm going to use the 5V line along with a 100ohm
resistor to get things going. You always want to get the right
resistor in conjunction with what voltage your LED is rated
at. If you're not mathematically inclined as me, you can
always go over to brutal's
resistor page to calculate your needs.
Here's my simple wiring scheme, I have
the resistor on the 5V line which connects to the HDD holder I
ripped apart. The other line is for ground, wire
accordingly. Wrap this up and you are set to get things lit.
Just shove the leads into the HDD LED
holder you ripped out and we're ready to go. Make sure you are
plugging in the correctly, the long end is + while the shorter is -
. Here's what you should get after plugging in your molex and
powering it up:
The last picture is the LED shining on
the wall, looks a lot better in person. Now that we have the
jist of wiring stuff together, lets start replacing everything we
can get our hands on. By the way, you most likely won't need a
resistor when replacing the LEDs in your case and so forth, there's
usually not that much voltage running through to your existing LEDs
that will pop your replacements. Let's start...