Inverter noise!!

williamn333 · 01-16-2004, 02:05 AM

Hey guys I have a jensen inverter which is like 300watt continuous and 600 watt peak. I am running my PS2 off of it and I am getting ALOT of engine noise. I get like a really really high pitched squeal almost when I at high RPMs. I have tried to put a ground loop isolator on the RCAs and that didn't help. I also am getting noise in the picture. Would a small cap on the 12v line help this? Thanks!

Confused · 01-16-2004, 03:06 AM

I fixed 95% of my audio problems by grounding the power supply (or a metal part of the computer) to the same ground point as my inverter/amps

Garry

MikeH · 01-16-2004, 06:52 AM

William....I did the same as confused (gounded my carpc case), but also lifted the 3rd pin (ground) on my 3-prong AC power plug that feeds the AC/DC brick that feeds my carpc. Most inverter noise disappeared.

Defiler · 01-16-2004, 08:27 AM

Quote: Originally Posted by MikeH

William....I did the same as confused (gounded my carpc case), but also lifted the 3rd pin (ground) on my 3-prong AC power plug that feeds the AC/DC brick that feeds my carpc. Most inverter noise disappeared.

Just asking not bashing...Isn't the 3rd (ground) pin there for a reason? I thought it isn't good to do that. Am I wrong on thinking this?

MatrixPC · 01-16-2004, 08:49 AM

Try NOT to run power and RCA cables together. If you run the Power cable on one side of the car, the RCA cable should be on the other side of the car. A big power cable (10GA at least, 8GA or 4GA is better) will help. A ground cable should be the same size or bigger than the power cable and as short as possible also help.

williamn333 · 01-16-2004, 12:08 PM

I don't have a PC in the truck yet. It is just an inverter with a satellite box and a PS2. It mainly does the noise on the PS2. Let me know what you guys think!

R3l0ad · 01-16-2004, 12:37 PM

Try getting a surge protector like a single port surge protector from your inverter to your PS/2. Make sure its a good one, don't skimp out on it!!! There is a link somewhere in the forums for one at radioshack.

Confused · 01-16-2004, 12:38 PM

Put a wire from a metal part of the casing of the PS2 to the same ground point.

Garry

Defiler · 01-16-2004, 12:48 PM

Quote: Originally Posted by R3l0ad

Try getting a surge protector like a single port surge protector from your inverter to your PS/2. Make sure its a good one, don't skimp out on it!!! There is a link somewhere in the forums for one at radioshack.

HA. I've been promoting that like they're goin' out of style. I totaly forgot about these for some reason. It took 99% of the noise out of my setup..

here is the link to the better quality one: http://www.radioshack.com/product.as...5Fid=61%2D2420

MikeH · 01-16-2004, 01:42 PM

Defiler

Quote:

Isn't the 3rd (ground) pin there for a reason? I thought it isn't good to do that. Am I wrong on thinking this?

Excellent question. I'm not an expert in this area, but here's my theory (I'm ready to be corrected if we have experts in the group)...

The 3rd prong is used in electrical power systems to provide a common case shield between devices that use the same AC circuit. This is supposed to prevent a lethal voltage from building up between the "touchable" parts of the devices (ie the cases), since the AC common (return) wire is typically not connected to the case. In the carpc environment the AC is generated locally at the inverter and passed thru a transformer which isolates the AC from the case. Therefore, the inverter case ground COULD be removed from the AC part of the system (by lifting the 3rd prong on a 3wire-2wire AC adapter plug), and tied to the DC part of the system thru a common ground wire. OR, as in my case, left floating, since this produced the least "noise" in my audio system.

Again, proceed at your own risk. This worked for me, with my el-cheapo WalMart inverter. Your results may vary.....but I'd love to hear how it works for anyone who tries it.

williamn333 · 01-16-2004, 05:07 PM

Defiler,
Did it take the video noise out of the picture? I notice I am getting some wavy lines and stuff from the inverter. BTW, thanks alot for that surge protector idea r3l0ad and defiler!!!!

Defiler · 01-16-2004, 10:25 PM

Never had Video noise before...How are you powering it? From your PSU or car +12?

williamn333 · 01-16-2004, 10:52 PM

I am powering the inverter from my 12v battery.