Stealing power from the mobo?

I want to power some LEDs from the motherboard, so that they turn on when the computer is on. How would I go about doing this?

I have the 8.9" One that came with Linpus.

Maybe I could steal power from one of the speaker cables? I'm looking to power at least 4 LEDs, hopefully as many as 10.

 

Motherboard usb port "CN11".

 

Thanks, but could you be a little more specific? Or point me to some literature on the subject? Do I need a resistor? Do I have to do parallel circuits with LEDs, or can I go serial? I have no experience with circuits, or electronics in general :?

Okay, so I found about the circuitry, now I just have to find out how to actually steal the power :twisted:

 

SEARCH:...

http://aspireoneuser.com/forum/search.p ... mit=Search

 

Did you read the search results yourself? I thought I did, and I didn't find any answer to my question there, but I will read again.

 

Yes I did. CN11 is mentioned in all this threads for one reason - it's extra USB "socket" on mobo - this contains 5V power as well...

 

I would recommend you reconsider attempting a internal modification until you some basic experience with circuits.

Start out simple by building an external LED assembly powered by a USB connector.

 

Thanks. Only 5V? I guess I'm going to have to do a parallel circuit then

On the other hand, If I steal power from the fan port, maybe the fan control software will be able to control the brightness of the LEDs?

Probably a good idea, but I don't know where to purchase this stuff. Couldn't find any shops in my country, but finally found some LEDs over at dealextreme.

 

I suggest you let your tech friends do this for you since you don't know anything.
Hooking up 5v vsb power in parallel won't get you any where. You'll still have 5v and have the same current as well (characteristics of MOSTF). You'll need to hook it to serial which is not possible or really really complicated on a netbook.

The fan is powered by 5v rail as well. It's the same power source as vsb (usb power).

Also, you cannot dim the LED with fan controller software even if you find a way to "mod" the fan control software. The LED needs a specific driving voltage. If it's too low or too high, it won't work or it'll break.

I highly recommend you to read some books or consult a tech friend for soldering tips before attempting this "mod" (it's not really a mod because it's kind of too easy).

First get a flashlight led controller. It's prebuilt and it accept a wide range of voltage, typically 3v - 9v. The flashlight led controller is also very cheap, typically below $2 USD shipped. It's small, star shaped for easy soldering, and pretty efficient.

Then just hook up some led to the controller and hook up the controller to a 5v power source then you're done.

Most DIY flashlight led controller have like 8-12 modes of brightness. It's all manual thus if you want to adjust the brightness, you'll have to use an hardware switch. You can put the hardware switch in the kingsonton lock port.

You can also turn off the led through windows if you want.

 

Thank you, this was very helpful
I would prefer to do it myself tho, as the main reason I have for doing it is learning. I'll try to find a flashlight led controller... I didn't see any on DX, do you know any good sites that sell this kind of stuff?

 

They are everywhere on dealxtreme.
eg.

http://www.dealextreme.com/details.dx/sku.20329
http://www.dealextreme.com/details.dx/sku.3256

 

Thanks! I thought they might be the ones I was after, but I wasn't entirely sure. I bought a multimeter too, so I can start having fun in a week or two
Thanks to everyone for their input.

 

What kind of Ied are you using? It would be cool if you use a high power LED. E.g.Cree P4 bin Led, they're dirty cheap and they're sort of bright, > 100 lumin under full power.

 

I'm embarrassed to have to say that I don't really know. I went with these: http://www.dealextreme.com/details.dx/sku.9077
Small and blue, with lots of great reviews

 

dont do this also if u use specil circit ur leds cn flsh to your musicbut i forgot the name =(

 

I got them today and made a parallel circuit to test, and they all work fine. They do get -hot- tho, I guess they don't like 5V, but they work perfectly well without any other trouble. Bright as hell too.

How exactly?

 

If you wire something to a USB port, then go into Window's Device Manager and disable the same USB port the power should be turned off.

 

Yea, I already tried that. No luck.

About this circuit of mine tho... If the USB cable delivers about 5V and 0.5A, and I have 10 LEDs in a parallel circuit. Will that the entire circuit consume about 2.5Watts?

0.5A Tot/10LEDs=0.05each
P=UI=5V*0.05A*10=2.5W?

 

Try this, Select the Power Management tab for that USB port and check the "Allow The Computer To Turn Off This Device To Save Power" box. Click OK.

 

I don't know which one it is exactly, but I've tried every single one. Nothing happens. I'm running the LEDs from the USB on the left side of the machine right now.