Testing out a carpc without a car!

mike6789 · 08-12-2006, 01:32 AM

Hey guys -

Can I just use the 12v source from a computer (like HDD connector) to power my carpc, I dont want to bring a car battery out in my house :|

Thanks!

Wiredwrx · 08-12-2006, 01:35 AM

Quote: Originally Posted by mike6789

Hey guys -

Can I just use the 12v source from a computer (like HDD connector) to power my carpc, I dont want to bring a car battery out in my house :|

Thanks!

Search is your friend.

http://www.mp3car.com/vbulletin/faq-emporium/51489-attention-newbies-faq-faqs.html, which has a link to http://www.mp3car.com/vbulletin/show...53&postcount=3

So is the SEARCH function on the forum.

Michael

YESindeed · 08-12-2006, 01:35 AM

yeah it kinda depends on how much the computer pulls but give it a shot.
it will prolly work out fine

YESindeed · 08-12-2006, 01:39 AM

Quote:

Search is your friend.

http://www.mp3car.com/vbulletin/showthread.php?t=51489, which has a link to http://www.mp3car.com/vbulletin/show...53&postcount=3

So is the SEARCH function on the forum.

Michael

i think hes asking if he can use a standard atx poer supply to power up his dc-dc power supply, if he is the link you provided doesnt answer that question

2k1Toaster · 08-12-2006, 01:41 AM

Yes it will work. Just ground pin 14 on the ATX connector to make the PSU supply voltage to all the rails, not just the standby, and chop into the yellow and a black of a 4pin molex. Good to go.

yellow 12v to constant, and black GND to ground, and then for ign. For the ign, just either tie it directly in with the 12v constant (so that when the PSU is on, it is on), or to get the feel of car, get a SPDT switch so that the Shutdown controller can be tested. Good Luck

mike6789 · 08-12-2006, 01:44 AM

Quote: Originally Posted by YESindeed

yeah it kinda depends on how much the computer pulls but give it a shot.
it will prolly work out fine

nah man, i just read... i have an m2-atx, 120w... there is no way a computer pushes 12v at 10a to the HDD conectors... or does it?

mike6789 · 08-12-2006, 01:45 AM

Quote: Originally Posted by 2k1Toaster

Yes it will work. Just ground pin 14 on the ATX connector to make the PSU supply voltage to all the rails, not just the standby, and chop into the yellow and a black of a 4pin molex. Good to go.

yellow 12v to constant, and black GND to ground, and then for ign. For the ign, just either tie it directly in with the 12v constant (so that when the PSU is on, it is on), or to get the feel of car, get a SPDT switch so that the Shutdown controller can be tested. Good Luck

ah ok, so it will work, excellent!

but what's this thing about pin 14?

2k1Toaster · 08-12-2006, 01:47 AM

Quote:

+5V @ 30A, +12V1 @ 16A (CPU1), +12V2 @ 16A (CPU2), +12V3@ 36A (Graphics, Drives), +12V1,V2,V3 = 66A (70A pk.), -12V @ 0.8A, +3.3V @ 30A, +5VSB @ 3.5A

Add up the 12v. Yes is can exceed 10amps on the 12v rail...
Taken from the PSU in the machine I am working on. Only 75% efficient so multiply the total by 0.75 and there ya go.

YESindeed · 08-12-2006, 01:50 AM

i dunno, try connecting it to a 12v on the mobo connector or something, look at the sticker on the ac-dc power supply your using and see what it has to say

mike6789 · 08-12-2006, 01:50 AM

ok, and i need to ground pin 14 on which power supply? the m2atx or the one that is suppling the m2atx, and why do i do this?

2k1Toaster · 08-12-2006, 01:51 AM

Quote: Originally Posted by mike6789

ah ok, so it will work, excellent!

but what's this thing about pin 14?

Do this:

Pin 14 always has power for the ATX standard. On the old AT standard. when you pushed the button, power went bye-bye. Hard Shutoff. Remeber the days of "it is now safe to turn off your computer"? No more with ATX.

Basically always power a line. When that line makes a full loop, (i.e. push the power button which really just shorts out 2 pins on the mobo that trace back to pin 14) <breath...> it turns on the rest of the rails. When you push it again, it tells the mobo and the mobo decides when to discontinue the short of pin 14 (i.e. after it has saved settings and exited windows, it un0shorts it).

kinda. A bit simplified, but it works

YESindeed · 08-12-2006, 01:52 AM

ground 14 on the one thats supplying the m2atx because thats what a motherboard usually does to turn on the power supply when you press the power button on a computer.

2k1Toaster · 08-12-2006, 01:52 AM

Quote: Originally Posted by YESindeed

i dunno, try connecting it to a 12v on the mobo connector or something, look at the sticker on the ac-dc power supply your using and see what it has to say

Why?!?!

just use a harddrive molex. Easier and cheaper to replace and you get like 10 of them compared to 1. And ATX standards say that 12v should be yellow. However there are those that aren't officially standardized, but it is the yellow one usually.

mike6789 · 08-12-2006, 01:53 AM

Quote: Originally Posted by 2k1Toaster

Do this:

Pin 14 always has power for the ATX standard. On the old AT standard. when you pushed the button, power went bye-bye. Hard Shutoff. Remeber the days of "it is now safe to turn off your computer"? No more with ATX.

Basically always power a line. When that line makes a full loop, (i.e. push the power button which really just shorts out 2 pins on the mobo that trace back to pin 14) <breath...> it turns on the rest of the rails. When you push it again, it tells the mobo and the mobo decides when to discontinue the short of pin 14 (i.e. after it has saved settings and exited windows, it un0shorts it).

kinda. A bit simplified, but it works

ah i see, well i was just thinking have the mobo still plugged in...

so like i have a tower running off that full size PSU and then i also use it to power tthe m2atx...

is this bad? if so, what will it break? lol thanks

YESindeed · 08-12-2006, 01:54 AM

no dont do that, that would be weird. plus together they would prolly suck too much power out of the supply