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Newbs: Some power/inverter/relay/remote start ideas

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  • Newbs: Some power/inverter/relay/remote start ideas

    Here is my situation:

    I have a P2-266 that I turned/am turning into a carputer. It has a whopping 128 megs of ram (in 32 pin not bad at all). I wanted to originally instal win 98 on it, however I remembered 98 requires a keyboard be plugged in to boot, and I did not want a keyboard in my car. So, I installed 2000pro. I had a problem though. The computer does not turn off when I tell it to shut down. That was a problem with my plan of running a relay off of a fan header.

    So, here is my solution:

    I bought an inverter. I don't have the money to buy a 12v PSU. My 500 watt inverter was $30. I WISH I had the knowledge to convert an ATX PSU to 12v, but I'd have to have a step by step tutorial (the soldering I could do, reading the schematics and figuring them out I could not). So, what I'll be doing with my relay is the following:

    I have a remote start, so want to boot remotely. My mobo DOES support power on when power is restored. I am going to have a relay on my inverter to turn it on and off. No new ideas. But, to get power to the relay, I am going to have 2 sources of power. One will be a wire running from the relay/fuse to the ECU, one from the amp's voltage detector from the head unit (but I don't know how much current that will supply, so don't know if that will work). Each will have a diode on it. Running a line from the ECU lets me start any time the engine is running, which lets me easily get the power with my remote start. The wire from the stereo to the amp will HOPEFULLY let me listen to music with the key turned back only. Unfortunately, shutdown is a bit of a problem. I am having to shut down manually each time before I cut power (so I don't have to worry about windows becoming ****y losing power all the time). Sure, it is merely a matter of remembering to press the right button, but still, I'd rather not have to do that.

    As for sound, I don't know what to do. I used an FM modulator in a test run this past weekend. It sounded like crap, and was a pain if you went in an area that had a radio station on that channel. I have an amp, but my head unit is plugged in. Anybody know if it will be a problem to hook the audio of the comp up to the amp along WITH the head unit using an rca splitter/combiner?

    Also, what is the max current I should think about drawing from an 8 gauge wire hooked to the battery that is about 10 feet long?

  • #2
    W98 doesn't require a keyboard to start. You're probably talking about your BIOS giving you errors. Disable error reporting and you should be gravy.

    For your startup/shutdown issues, just plug that relay into two pins of your parallel port and (based on your skizzles) write a small program to monitor when the two pins are shorted or not. Power it directly from your battery so that when your car turns off and your voltage drops to ~10V, the relay opens and your computer is told to shutdown. I have some C code to do just that if you're interested.

    Unless you're using your head unit to control the volume of your computer, just run a wire from your sound card to your amp.

    8 gauge is plenty for powering a PC. I'm using 10 gauge without problem.
    Don't Click


    • #3
      Oh I'm not talking the 8 gauge just running the pc. It is running the amp and the inverter (which may or may not be used JUST for the PC).

      Also, I plan on just running a wire from my sound to the amp, but I also do use the stereo (for cd's or FM radio) and am asking about possible problems having two inputs on the amp.

      I was almost positive 98 required a keyboard be plugged in to start. You are probably right though, I'll have to drag the computer in, I needed to do a bit of software changes anyway. I'll check and see if the motherboard requires a keyboard or not. If not, I have a spare HD somewhere, I'll try formatting it and installing 98 (though that'll probably be quite a bit later).

      My head unit is an alpine 7817. It seems to be about impossible (for me anyway) to find any info on it. It has a connector that I imagine is for a cd changer. I'd like to find out what the wires do so I can maybe hook in to that with my audio and use the head unit to control the volume. Anybody good at searching google? Thus far my searches have turned up nothing. The connector reminds me of an AT keyboard. It has 8 pins total.

      That is my crappy ASCII representation of it. The box at top is just the thing that orients the plug. The two center pins are surrounded by the other 6, 3 to a side. If anyone knows what these do, let me know please.


      Also, my computer wont start when no video card is plugged in. It boots, beeps some, and restarts eventually, keeps doing that in a loop. Do you think turning error reporting off would allow windows to boot? Will windows boot with no video card? It isn't important if my comp stays in the trunk, but if I try to fit it somewhere (like my glove box), then I'll need the video card off of it.


      • #4
        Well I found something that will work well for my relay. The ABS fuse has no power to it when the car is off, but has power when the car is running (on both the key and remote start, already checked that issue). So, I'll hook in there to remote boot the computer. As long as I remember to stick the key in the ignition and not press the brake, I won't have to worry about the comp rebooting on me.

        I also found the wire that turns the amp on WILL run a relay, so that is good news. I may have to go ahead and install the relay and inverter tomorrow. Fortunately, that won't be particularly difficult since I had the foresight to buy sockets for the relays when I purchased them It'll merely be an issue of running a small wire from my hood to my trunk. I have some speakerwire that'll be more than overkill. SOMEWHERE I have some phone wire that would be perfect for this since it is so small.

        Something I've thought about doing is sticking a big capacitor in line with the relay. I'd need something that would be able to provide approximately 12 volts and 200 mA for up to 2 seconds. That should provide me enough time to turn my key to the rear and still be able to listen to the music when I park somewhere. Not sure what size capacitor that would take, but it shouldn't be TOO big I wouldn't think. I might look that up somewhere.