Home Pc to CarPc

**sup2jzgte** · 10-13-2005, 03:15 AM

Hey whats up, I must say you guys and gals have a GREAT site going here, very very helpful. Now here is my question, I have a newer desktop that has been sitting around my house not being used, because I have 3 laptops and 4 desktops, it kind of became a spare. Now is there anyway I can put it into my car, or is there a certain kind of computer you need for it? I know I would need to change the power supply and what not, but is this possible, if so what do I need to do? Well thanks inadvance for the help, now Im going to keep surfing this great place

**sy_pug306** · 10-13-2005, 03:28 AM

Hi and welcome.
All you need is a PSU like the opus with the start up and shutdown controlers a screen either in dash or on. Cables long enough to connect it all together and the software for the front end and anything else you wanna run.
There are plenty of places to get more info, just use the search button and you'll find everything you need.

**sup2jzgte** · 10-13-2005, 03:56 AM

Thanks man Im still searching the hell out of this place now

**MatrixPC** · 10-13-2005, 10:10 AM

Read the FAQ for power option to see which one can power any of the PC you have on hand.
The limit to the carPC hardware is the PSU.

**sup2jzgte** · 10-14-2005, 08:29 AM

Ok I have been searching this site for a few hours so far and have learned a fair amount, but I have a few more questions. Now I don't think these questions call for a whole new thread so I figured I would just post it in my orignal thread. As you know Im thinking of using one of my home computers for my car. So here it goes. I just took apart my Compaq and the power supply is 200watts, so that would mean I would need to get a 200watt DC power supply, correct? Also does the make and model of the motherboard effect which PCU I should get? Now I know most people will think these dumb questions, but this is my first attempt at this, I mostly work on engines and audio, so Im a total newbie to this aspect of this kinda thing. Oh yeah the place I want to put this is made for a cd changer and is about 18" wide 9" high and 15" deep. Now what I want to do is use this space as the CASE instead of building one, and in addition to the CPU fan I was going to install 2 12" AC/DC fans on a switch so I can make sure it stays cool in there, do you think that is a good idea? I will try and take a picture of it when I get a chance

**kbyrd** · 10-14-2005, 01:41 PM

Originally Posted by sup2jzgte

I just took apart my Compaq and the power supply is 200watts, so that would mean I would need to get a 200watt DC power supply, correct?

Maybe. You're right that a 200W DC PSU will probably power your computer. But, it's not just about how many total watts, but how many amps the computer needs on 12V, 5V, and 3.3V rails. You could have a 200W PSU that could only handle 1 amp on the 12V rail, but have your computer need 2 amps on the 12V line.

Also, many people run other things (LCD screen, USB hub, etc) from the 12V and 5V lines on their PSU. You don't have to do this, you can power the LCD from the car (not recommended) or get point-of-load-regulator for the other devices. But, if you do power these things from your PSU, you have to account for their draw.

Originally Posted by sup2jzgte

Also does the make and model of the motherboard effect which PCU I should get?

As long as the PSU and the motherboard has an ATX connector you should be fine. I know some mobos have this P4 connector, I don't know if many DC PSUs have that.

As for a case, I hacked up a plastic box. It's hidden away, doesn't need to be fancy. Check out the show off your projects section for ideas.

**don-m** · 10-15-2005, 12:26 AM

It may be a bit harder to find a PSU for that machine than most. Compaq, HP, Dell, Gateway, eMachines pretty much all the major OEM computer manufacturers have this REALLY nasty habit of using proprietary PSUs. Now in most cases that simply means they're a funny shap or size and a normal ATX PSU won't physically fit inside the case, however I know from experience that both Dell and Compaq have used proprietary wiring paterns in the past (I don't know if they still do but I wouldn't put it past them). The size and shape of the PSU is the same as a regular ATX, even the connector is the same, but they are wired diferent (ie on a Dell PSU you may have a 3.3v line where a 12v line is on a normal ATX) and if you use a normal one there's a pretty good chance that it will fry the Mobo.

Do a quick google for "ATX pinouts", grab a multi-meter and check. If you know that you have a proprietary PSU it's easy enough to modify the new one so that it will work, but if you don't check it and it does turn out to be proprietary, then you're gonna have a problem.

**sup2jzgte** · 10-15-2005, 02:49 AM

Originally Posted by don-m

It may be a bit harder to find a PSU for that machine than most. Compaq, HP, Dell, Gateway, eMachines pretty much all the major OEM computer manufacturers have this REALLY nasty habit of using proprietary PSUs. Now in most cases that simply means they're a funny shap or size and a normal ATX PSU won't physically fit inside the case, however I know from experience that both Dell and Compaq have used proprietary wiring paterns in the past (I don't know if they still do but I wouldn't put it past them). The size and shape of the PSU is the same as a regular ATX, even the connector is the same, but they are wired diferent (ie on a Dell PSU you may have a 3.3v line where a 12v line is on a normal ATX) and if you use a normal one there's a pretty good chance that it will fry the Mobo.

Do a quick google for "ATX pinouts", grab a multi-meter and check. If you know that you have a proprietary PSU it's easy enough to modify the new one so that it will work, but if you don't check it and it does turn out to be proprietary, then you're gonna have a problem.

Thanks I will do that tomorrow

**agentloveless** · 10-15-2005, 10:57 AM

Yo Kbyrd,

Maybe. You're right that a 200W DC PSU will probably power your computer. But, it's not just about how many total watts, but how many amps the computer needs on 12V, 5V, and 3.3V rails. You could have a 200W PSU that could only handle 1 amp on the 12V rail, but have your computer need 2 amps on the 12V line.

Power = voltage x amperage

So it is about the wattage because that is what will determine the max amperage. Since it is all comming from the same source (12V dc) any of the rails can provide that power.

**kbyrd** · 10-16-2005, 06:00 PM

Originally Posted by agentloveless

Yo Kbyrd,
Power = voltage x amperage

Sure, I would have said:
watts = volts x amps

Originally Posted by agentloveless

Since it is all comming from the same source (12V dc) any of the rails can provide that power.

This is absolutely wrong. Read any spec for a power supply (AC->DC or DC->DC). As an example, I'll quote the ones for the M1-ATX:
5V Rail: 10A max
3.3V Rail: 10A max
12V Rail: 2A max.
5VSB Rail: 1.5A max
-12V Rail: 0.16A max

Since these specs also say the max output power is 90W, I assume you can't actually draw the max amps from all rails at the same time.