LED for power and HDD

[KaminaAyato]

I was wondering how much voltage flows into the 2mm LEDs. I was thinking of changing the green power LED to a white LED but that one requires about 9 Volts, and the blue for the Hard Drive.

Im running a Gigabyte 7VAX Rev. 1.1. so I'm not too sure if it sends enough power to run the new LEDs.

Thanks
-Nick

 

[mattg2k4]

I'm pretty sure it varies by the motherboard from 3.3-5v, but definitely not 9v.

The power supplies standby power is 5v, so unless you want to build/buy a step up switching power supply to run off 5v, you need to choose another LED.

 

[xonik]

If you really want to use this 9 V LED, connect it to any available +12 V line and a ground, and then use an appropriately selected* resistor or voltage regulator to drop the voltage down to the specified 9 V forward drop.

* This utility can help you select an appropriate resistor for your application: http://linear1.org/ckts/led.php

 

[linear]

9V doesn't make sense for a white LED. Even as a maximum rating.

The white LED, unless it's a special application, should have a forward voltage around 3.3V @ 20 mA. I would recommend that you just use the white and blue LEDs as drop-in replacements for the current ones. The circuits driving them will usually handle the white and blue just fine.

I'm typing this on a machine where I swapped for white, I've got another two in the next room where I swapped for blue. No resistors or anything fancy anywhere, just a straight swap.

That's a good calculator though.

 

[xonik]

Yeah, I think that sounds high myself. I have a few types of white LEDs from a couple suppliers and their forward voltage drops are all in the 3.0-3.5 V range.

 

[KaminaAyato]

Thanks guy, I think those guys who sold it to me kinda exaggerated on the voltage requirements =\

-Nick