DC-AC-DC power supply or DC-DC powersupply

alansupra94 · 06-16-2008, 10:50 AM

I was wondering what is the best and most reliable way to power the computer.

I am running a GX240 motherboard with a 2.4Ghz P4 and 512MB. I am also installing two 500GB SATA drives, possible an external HDD and a DVD-RW drive. Still not sure on a graphics card but I think I am leaning to an old FX5200.

I already have a 300W inverter running to a ATX powersupply but I am not sure if it can keep up and before I buy a 500W or 1000W one I might as well ask if the DC-DC ones are better

Thanks
Alan

Bugbyte · 06-16-2008, 11:14 AM

Over 300 watts you are going to need to go with the inverter. The first thing you need to do is figure out how much power your computer draws. Go to either the FAQ's for links to power calculators or the FAQ Emporium for even more FAQs.

alansupra94 · 06-16-2008, 11:20 AM

sweet thanks for the fast responce...yeah I might just buy a 1000W inverter and rest easy

I just wonder how much battery it would drain.....

Bugbyte · 06-16-2008, 01:54 PM

Well, it isn't the inverter that drains the battery -it is your computer. Just because the inverter says it can supply 1000 watts doesn't mean that it draws 1000 watts at all times. If you have nothing hooked up to it, it should draw near zero. If you have a 400 watt PC connected to it, you will see it drawing a little north of 400 watts (there's some level of inefficiency in the device).

I do know that some inverters tend to draw a small amount of power even when the computer is turned off and will eventually drain the battery. You have to switch them physically off to prevent power draw.

TruckinMP3 · 06-16-2008, 02:06 PM

figure out what your system will draw for power and buy a DC to DC supply.
It will save you from buying an inverter then later a DC to DC option when the inverter does not work well.

alansupra94 · 06-16-2008, 04:31 PM

Well the thing is that I doubt any DC-DC powersupply will be able to power my computer

It is basically a full computer.....in a custom stainless steel case that I am making

cameronlazzari · 06-16-2008, 06:39 PM

Do not go with an inverter -they are very loud and you will get a ton of buzzing on but up and sirius, xm, hd radio, or any other radio you put in. I am dealing with it as we speak. Invest in a set up that you can use a AC to DC adapter....your will be better off in the long run.

Cameron

Bugbyte · 06-17-2008, 08:20 AM

Inverter installations without noise *can* be done. Just ask Enforcer. And DC-DC setups can also experience noise. Two of the primary rules are to ground everything to the same point, which reduces the chance of a ground loop and don't run your power wires next to your audio wires.

bambam · 06-17-2008, 11:39 AM

Quote: Originally Posted by alansupra94

I was wondering what is the best and most reliable way to power the computer.

I am running a GX240 motherboard with a 2.4Ghz P4 and 512MB. I am also installing two 500GB SATA drives, possible an external HDD and a DVD-RW drive. Still not sure on a graphics card but I think I am leaning to an old FX5200.

I already have a 300W inverter running to a ATX powersupply but I am not sure if it can keep up and before I buy a 500W or 1000W one I might as well ask if the DC-DC ones are better

Thanks
Alan

I use an Opus 320W and power my ASRock 775i65G MB with 1G ram, 500G Seagate HD, 8.4" lilliput, 2 fans, usb hub and 5 usb devices with no problem. On my test bench, I also had a 2nd HD and a DVD drive.

As far as noise, I have absolutely none. I grounded everything to a single ground (including the MB) and use a PAC SNI-1 Ground Loop Isolator & RCA Noise Filter.

My project can be seen here:
here

Side note: I use onboard graphics and it plays all the movies, etc. that I throw at it so unless you are playing high end games (graphics), do you need a video card for more power drain?

DarquePervert · 06-17-2008, 02:48 PM

Quote: Originally Posted by alansupra94

Well the thing is that I doubt any DC-DC powersupply will be able to power my computer

Have you read the FAQs on POwer supplies?
http://www.mp3car.com/vbulletin/advfaq.php

Quote:

It is basically a full computer.....in a custom stainless steel case that I am making

A full computer as opposed to... what? A thin client terminal? A WinCE device?

Chairboy · 06-17-2008, 03:26 PM

He may be operating under the assumption that we use hopped up abacuses and Apple ][s in our cars. :P

Alansupra: Inverter installs have a high failure rate in the sense that lots of people who start with them in mind end up either switching to DC-DC later or get rid of their carputer in frustration because of the hassle of day to day use. I'm sure a bunch of inverter users will jump in and tell me how wrong I am, but I know three folks personally who ditched their carputers because of inverter woes.

Also, the big stainless case doesn't actually increase your power consumption. Just an FYI.