Question About Led's And Resistors Options

[j0rpi]

So i saw some mods where they had changed the front panel LED's with blue ones. Since i'm not the best at electronics, i took a look at chapter 3 of "Hacking The Xbox" where he installs 2 blue LED's. He mentions that the LED should be 3mm and that the voltage should be around 3v. So i wonder if this LED will work?It's 3mm, 2,8-3.4v, 20mA, 2100mcd

Now regarding resistors - I find these HDD/LAN activity led's very cool, so i thought about making these aswell, but it's very hard to find the right components in Sweden. I've read most tutorials, and they have often used a 220 ohm 0,5W resistor, but i can only find 220 ohm with 0,25w (1/4). Is it possible to use any other resistor? And what LED's should i use for HDD/LAN activity?

Answers are highly appreciated.


This post has been edited by j0rpi: Mar 12 2012, 08:39 AM

[cricri_pingouin]

It doesn't have to be 3mm LEDs: I have 5mm multicolour LEDs for HDD and network myself. I never bothered about the voltage rating of LEDs, I just make sure they get 20mA and never had a problem!

You need about 20mA for a LED. Ohm's law: U=RxI so R=U/I=3/0.2=150 ohms
220 ohms will be fine too, you'll just get a little less than 20mA, which is fine.
Now P=UxI=U^2/R
In your case: P=3^2/220=0.041W, so you can see a quarter watt resistor is fine. In fact, IIRC, that's what I have on my 5mm LEDs.

*EDIT* bloomin' typos!

This post has been edited by cricri_pingouin: Apr 9 2012, 12:51 AM

[MrMajst3r]

If you want to change LEDs in front panel, you don't need to install resistor.

I suggest to buy RGB LED (and cut 1 leg), or to buy set blue + red LEDs. I have the second option, and it can be on blue (instead of green) violet (instead of orange) and red.

You must to modify a bit the front panel with sharp knife to use 2 couples of LEDs (if you use RGB LED, it's unnecessary).

[MrMajst3r]

If you want to change LEDs in front panel, you don't need to install resistor.

I suggest to buy RGB LED (and cut 1 leg), or to buy set blue + red LEDs. I have the second option, and it can be on blue (instead of green) violet (instead of orange) and red.

You must to modify a bit the front panel with sharp knife to use 2 couples of LEDs (if you use RGB LED, it's unnecessary).