noice when using 12V from cig-lighter

**loscooby** · 12-21-2003, 06:06 AM

Hi,

i have recently installed my carputer, it is epia-based(m10000 motherboard).

When I power the PC using my std. power-supply(run an extension-cord to my garage) the sound(aux on headunit) is ok, no noice or anything!

But as soon as I power it from the cig-lighter it produces a lot of noice, everything else is working fine(Video showing movie etc) but the sound is really only a lot of noice.
I have a dc-regulator hooked in line with PC.

I use the ground from the cig-lighter, is this the cause of my problems?

Has anybody else had any problems with this?

/L-O

**Dan Marsh** · 12-21-2003, 01:07 PM

Could you tell us more about how power is set up in the car? Do you have the regulator hooked up to an ATX style DC-DC supply or are you powering an invertor and then using a standard AC ATX supply?

**hijinks21** · 12-21-2003, 01:23 PM

you can try to ground your PSU to the frame of the car. Do this by ground one of the screws that hold the PSU to the case to the car frame. Using a cig lighter inverter will usually crate a lot of noise. Grounding the PSU might help but probably won't. THe proper way to do it is get the 12v from the battery and ground the inverter and the PSU to the same spot on the frame.

**loscooby** · 12-22-2003, 12:07 AM

Thanks guys!

My PC has a built-in dc-dc converter (ATX i think) along with a power regulator.

i will try grounding the regulator directly to the chassie instead of using the ground from the cig-lighter and if that does not work get the +12V directly from the Battery.

/L-O

**zijester** · 12-22-2003, 03:17 AM

Common problem. Try using a fuse tap. That will help.

**Goose** · 12-27-2003, 08:23 PM

Originally Posted by zijester

Common problem. Try using a fuse tap. That will help.

fuse tap? and it is? 8can you explain, not so good in engilish)
maby you got some pictures?

**adamis** · 01-01-2004, 04:06 AM

Not sure about a fuse tap, I used a ground loop isolator that plugged in between my amp and the 1/8" stero jack that went into the computer and it took care of my problem. Yes I did try grounding it to a couple of different places but it didn't make much difference. The ground loop isolator took care of the problem and didn't affect my audio quality enough for me to notice.

I would try to get this problem fixed by proper grounding but if it doesn't seem to work try the ground loop isolator. The one I got was from wal-mart, it cost 14 bucks and it is designed to plug into the audio RCA cables (the ground loop isolators that plugged into the power source for the computer never worked but the RCA one did.)