Question about the rgb header on formula VIII

[Sleazster]

I have been doing some research for a build I am about to start, and I was wondering if the following setup would work


I am thinking it should if I can find a suitable ground on the motherboard to tie the ground to.

If this would be feasible, then the RGB header and aura software could control upwards of 60A worth of rgb strips

[Nate152]

Hello Sleazster

Welcome to the ROG forum !

I don't see how it's possible without the 4th ground pin. The RGB header is rated at 2 amps (24 watts) and supports 5050 led strips up to 2 meters long with a 4-pin RGB connector.

https://www.superbrightleds.com/moreinfo/rgb-bars-and-strips/led-light-strips-with-multi-color-leds-...

[Sleazster]

Nate,

You are correct, I need a safe ground to tie the motherboard to the power supply.

Or maybe not if I just use a rail off of the pc power supply.

I am hoping an asus engineer accidently gets a hold of this post 😄

[Nate152]

I'm not sure of the price of that contraption you have connected to the motherboard but if you want a bunch of LED strips another option is to get a fan controller.

Lamptron FC5-V3 has 6 channels at 30w per channel. A 12" led strip uses 2.5w so that = up to 72 12" led strips. If you want to go this route Dazmode has nice cabling/splitters for doing it this way, you can dim them but they won't be RGB.

http://www.outletpc.com/bj3656-lamptron-6-channel-lcd-fan-controller.html

You could do your own version of RGB but will cost more doing it this way.

channel 1 - red led strips
channel 2 - orange led strips
channel 3 - yellow led strips
channel 4 - green led strips
channel 5 - blue led strips
channel 6 - purple led strips

[Sleazster]

Nate that is the beautiful thing. It would cost less than $10 and be controlled by the motherboard, so they would all sync with the aura software.

Also I made an error in the info, TIP120 ($0.75 each) can handle 5a.

IRLB8721 ($1.75each) power mosfets can handle up to 16 Amps of continuous current - so that's at least 750 5050 leds at bright white. So you could in theory control 10 + meters of leds.
I have powered strips like this before with an arduino (which sources 40ma per pin), and could do so again. I just would prefer to have them controlled by the motherboard.

If you are curious as why I want so many, I am planning on make a sit stand desk case that will be 6ft X 3ft.

[Nate152]

Yes I was curious as to why you want so many, I thought you were lighting the inside of your house too. 😉

The 5050 led's must have the 4 pin connector, as for connecting a ground lead I have no idea where you'd connect it. If you're going to pursue it I'm anxious to know if you get it working.

[Sleazster]

With any luck an asus rep will see this and give an answer.

Otherwise I might get a cheap B150 mb and try it out, don't want to blow up a $400 Formula mb

[Legolas]

Here is the RGB specifications, they have 12V, 2A limit. You have only 6Ohm of resistance to play with.

[Costas]

Sleazster wrote:
I have been doing some research for a build I am about to start, and I was wondering if the following setup would work


I am thinking it should if I can find a suitable ground on the motherboard to tie the ground to.

If this would be feasible, then the RGB header and aura software could control upwards of 60A worth of rgb strips

Yes the basic concept will work fine.

You only need a ground from one of your power supply leads so the FETs can reference to that.

The only thing I would add is some 100 ohm resistors in series with the gate leads of the FETs. This is to help isolate the gates of the FETs from the mobo.

[Sleazster]

Costas,

Thanks for the reply, and thanks for the suggestion about the resistors. I am thinking about using a molex connector and get the 12V from the pc power supply. That would fix the ground reference problem, and drawing 16A from a 1200w power supply shouldn't hurt.