Electronics Molex to LED

I have this 60,000 MCD led rated at 2.2V @ 100mA.

Being a complete electronics newb, any idea how I can easily hook this up to a 4 PIN molex connector as a cheap light source for case lighting?

 

You are going to need the proper resistor to convert the molex from either 12v or 5v into your LED's input of 2.2v

 

That's it?

 

yea pretty much the molex is something like

---\
() | +12v (yellow)
() | Gnd (black)
() | Gnd (black)
() | +5v (red)
---/

So if you can find the resistor to convert it from either 5v or 12v, you can find the proper resistance by using the formulas or a calculator, if you have the Male End of molex you can just solder the wires directly to that connector, and just plug it in wherever you want a light source

 

A little help is needed here.
The resistor is calculated using the following
Vs-Vl/Il
Vs = Volts supply (eather 5v or 12v)
Vl = Volt load (led's 2.2v)
Il led's current(100mamps or 0.1 amps).
so
12-2.2/0.1

 

Therefore...

+12v
Gnd
Gnd-------------------------------------|
+5v -----------(resistor)--------------- LED

Is that setup right? What resistor should I use?

 

is it realy 100ma that seems like a lot for a led but if it is then you will need a 33ohm resistor.

 

The maths gives 28R, there's a 30R commonly available which is a bit nearer on a 5V supply. 33R will give the LED 85mA, a 30R 93mA. Use a 0.5W or more.
Or for the full 100mA, use two 56R in parallel.

 

lol i was lazy and just used http://led.linear1.org/1led.wiz
i did a 3 hour maths exam today and could not be bothered to do anymore

 

A little diagram or schematic would be major help, thanks!

 

http://led.linear1.org/i/series0.png

 

that is the diagram correctly made.
Ohm's law. Good for led users.

 

You will need a 510 OHM resistor, if you take the power from a 12V wire.

(brown, black, black, brown, green I think)

 

Thanks!

But what if I take it from the 5v?

 

what you do is
V(supply)-V(led)=current X resistance
so
5 - 2.2 = .1 x R
so
2.8/.1=28ohms

 

Perhaps now is the time to mention that thats a 5 band risistor and that there are also 4 band risistors

Erm where did you find that? that will realy confuse him when what i posted is the standered formuler and what you posted is just damn strange
NOTE ON BLUE LEDS
I tend to use 12v lines for case lighting (i have loads of leds for cars) but when im modiyfing front pannels i use 5V which means you realy need to pay attention when buying leds.

 

thats just ohms law with the led bit on it.
V=IR

 

No ohms law is r=v/i
not vs-vl=i/r

 

Maths for dummies

If V/I = R

Then V = IR

And I = V/R

It's no good parroting a formula if you don't know how it works.

 

I know ohms law and the corrected version for led (im a sparky after all) its just the way he wrote it looked very confusing. is it some sort of american way of doing it because i was always thaught the versions i know not the odd backwards version.
vs-vl=i/r its wrong anyway because V=I X R
Given that then V=0.00357, erm thats a little different to V=2.8
even a 5 yeay old can spot that !