Results 1 to 2 of 2

Thread: Another idea about powering a carputer

  1. 05-26-2003, 08:20 AM #1
    vbi
    vbi is offline
    Newbie
    Join Date
    May 2003
    Location
    Caput Mundi
    Posts
    6
    Send a message via ICQ to vbi

    Another idea about powering a carputer

    I have my system setup at 90%:

    Digitalww TM-701L with touchscreen
    Epia M 10000 with 256Mb of Ram and 80Gb HD.
    Procase DC-DC power supply.
    Custom built case in the car glovebox.
    MediaEngine.

    Everything runs fine, but I'm little scared to use the system with the engine running, because of the high voltage (14V)

    I have some few questions:

    Can the digitalww screen works @ 14V?
    I read about the procase... some blew, some are ok.

    I would like to use a small gell battery to operate the PC so I'll have a "tank circuit" while cranking and also a backup battery if some idiots try to steal the car. I'm working on a GSM alarm operated by the PC.

    Do someone have allready tried a project like this???

    I read about the "tank circuit" with a battery instead of a capacitor, can I wire the main battery (120A) with a small (say 5A) battery without any problems???

    Thanks a lot.
    Reply With Quote Reply With Quote
  2. 05-26-2003, 08:38 AM #2
    stimps
    stimps is offline
    Variable Bitrate stimps's Avatar
    Join Date
    Nov 2001
    Location
    brisbane
    Posts
    326
    Send a message via MSN to stimps

    eh?

    You can get a large current germanien diode (only drops 0.3volts) and put it in series with a smaller battery, like a 4Ah gell cell and hook up the power supply to the PC to that. That way, its constantly getting a charge from the cars electrical system (albiet minus 0.3volts.....not much to worry about) but if the system goes to cranking voltage, which can be as low as 9 volts, the one way diode will prevent any power rushing back out of the gell cell into the cranking circiut of the car, and stay at 12.5 volts or so. The PC wont even feel it.

    If you cant get one of those diodes, a normal large power diode will work (10 amps or so) silicon. Your gell cell voltage will be 0.6volts below car voltage, but if you system charges and runs at 14volts, then your gell cell will still be at 13.4volts maximin most of the time. Heaps of head room.
    Reply With Quote Reply With Quote
« Previous Thread | Next Thread »

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Forum Rules