PDA

View Full Version : G75 Motherboard 12V source



Guido7142
04-21-2013, 06:59 PM
Hi, I am planning a little project for my G75 and would like to know if any of you knows a 12V source from the motherboard of the notebook.

Thanks.

ggBanks
04-21-2013, 07:13 PM
I don't know about the 12 volts, but you can get 19 from the power plug, or 5 from any USB.

Guido7142
04-21-2013, 07:20 PM
I am looking for a 12V or more source that can deliver even when power plug is disconnected.

ManOfBusiness
04-22-2013, 02:10 AM
Pull it straight from the battery pack fins @14.4v and use resistors to get your 12 volts, most reliable source.

Guido7142
04-22-2013, 02:42 AM
I thought so but, could I cause any overload damage on the board or the battery ? I just want add some things that will consume 2W maximum.

ggBanks
04-22-2013, 06:39 AM
No. The worst thing that will happen is that the battery will drain faster, but you cannot overload the system with just 2W.

Guido7142
04-22-2013, 01:20 PM
Now it occurrs to me that if I hook up something to the battery fins, as you suggest, when I turn off the PC that thing would still be running right ?

Guido7142
06-02-2013, 08:03 PM
Does anyone know how the battery pins must be connected to get the power from it ? I hear you need to short two pins to get the negative and some other things too. I will be doing all the work over the pins in the motherboard and not on the battery so anyone has any safety suggestions ?

ggBanks
06-03-2013, 06:19 AM
There are a lot of fins on the board, and I don't know which ones you should use, but you could use a 12V voltage regulator that will bring your voltage to exactly 12V. It will work better than with resistors.

About the battery, I don't know if its the same with all laptop batteries, but I found somewhat of an explanation:
21085

I think you should use just the 2 most outside fins to get the 14.4V

Guido7142
06-03-2013, 07:51 PM
I tried but the thing is that the battery has a circuit inside that decides whether it sends power or not, that is why it has so many pins and some of them are data. When I remove the battery to test which pins contain the voltage I get nothing, apparently the battery is not 'ON' and you need to short some other pins to make it start. These pins all have their respective lines in the motherboard, those are the ones I will be using once I detect the voltage pins.

ggBanks
06-03-2013, 10:07 PM
Maybe its the Switch description in the picture, and you have to short the 2 lowest fins before the big one at the bottom, but that's just speculation. Better do some more research before you fry your battery.