startup/shutdown controller question

**enhanced08** · 06-11-2006, 02:33 AM

Here is a simple question about the DIY controllers I have seen on here. Do they turn the system on and off by the key (like a typical head unit is turned on/off) or do you still have to turn it either on or off?

The way I understand the settings/setup of the controllers is that they can either shut it down or turn it on via turning the key, but not both. If you have your BIOS set to "power on after power failure" then whats keeping it from turning on while the key if off? If the key cuts the power to the system then how is the system to shutdown properly?

Sorry if this is explained somewhere, I cant seem to find it.'

TIA

**vcbb5** · 06-11-2006, 02:42 AM

http://mp3car.com/vbulletin/showthread.php?t=54143

Mine is the 2nd one, the "ghetto" one, lol

mine does it by the key (but is also switched so i can have it stay off). Mine also shuts down via the key. I have it to startup after failure, but if you have the system shut itself down it doesn't repower up until a power loss, and than a regain of power (ie inverter off, back on).

I would, however, recommend a commercial shutdown controller over a diy (after doing one).

**PURDooM** · 06-11-2006, 02:57 AM

the m2-atx converts your cars current to current sutable for an ATX power supply, and also includes your startup and shutdown controler which is controled by the on/off of your carkeys. Thats the easiest and most cost effective and power efficent solution. It makes nearly no line noise, has very little power loss, and can run your computer for hours when the engine (alternator) is off.

**enhanced08** · 06-11-2006, 03:29 AM

vcbb5, why would you buy one over DIY, any specific reason?

I dont know if I can use a DC-DC PSU for my setup. 160 watts doesn't seem like enough power. I plan on having a 1.6Ghz P4, 512MB RAM, boot from a CF card, 160GB hard drive, DVD-ROM, webcam, wifi card, and a lilliput monitor.

**DarquePervert** · 06-11-2006, 08:31 AM

I'm willing to bet you haven't even bothered to calculate the power draw from your proposed setup.

Here's some reading that will help you do just that: FAQ: Will <insert PSU model> Power Supply work with my system?

**enhanced08** · 06-11-2006, 12:19 PM

Actually I have calculated it, but I have always been told to add to the wattage your computer should use just to be safe. Its better to have a larger wattage PSU than one thats too small.

According to that thread, the m2-atx has 96w on the 12v rail. My CPU will use 80w of that leaving only 16w for the rest of the system. Using different power calculators I'm getting between 230 and 250 watts so.... I'm thinkin that I can't use the m2-atx, or any DC-DC for that matter. I read where about 200w is the max for a DC-DC.

**DarquePervert** · 06-11-2006, 12:56 PM

Wholly untrue. That just tells me that you're not done researching or reading.

My suggestion is to reconsider some hardware choices for less power consumption. Laptop components (primarily HDD & optical drive) draw significantly less power. More importantly, they don't draw on the 12v rail.
Also, your CPU draws a lot of power. There are lower-power P4 models that will work in your board and still work within your power restraints.

There is also the DSATX which provides 220w total. You could very well combine that with another regulator for the Lilliput and be in business. It's an expensive option, though.
I think you'd be better off financially by looking for a CPU with a lower power draw and/or laptop drives.

**enhanced08** · 06-11-2006, 01:09 PM

Well, I already own the CPU. Its out of an old system that the motherboard died in. I also own a standard ATX PSU from the same system, all I need to buy is a board, optical drive, RAM, and HDD. For what I've got already and what I want to endup with I think DC-DC is the wrong way to go.

**zootjeff** · 06-12-2006, 02:33 AM

Originally Posted by enhanced08

Actually I have calculated it, but I have always been told to add to the wattage your computer should use just to be safe. Its better to have a larger wattage PSU than one thats too small.

According to that thread, the m2-atx has 96w on the 12v rail. My CPU will use 80w of that leaving only 16w for the rest of the system. Using different power calculators I'm getting between 230 and 250 watts so.... I'm thinkin that I can't use the m2-atx, or any DC-DC for that matter. I read where about 200w is the max for a DC-DC.

The DSATX should power what you've discribed no problem. People have powered much hungier systems than that with it.

**Haystack** · 06-12-2006, 03:35 AM

dc-dc is almost litterly the only way to go. I mounted a power inverter in my with a laptop and I still have all kinds of problems with it. I should only be pulling 80watts or so, and I am running a 400w continuous and 800w peak inverter with nothing else plugged into it and it still pops every once in a while. I bought a dc-dc one that plugs into the cigarette lighter, and havent had any problems, not even when cranking.