Results 1 to 9 of 9

Thread: Switching Power Input

  1. #1
    Variable Bitrate
    Join Date
    Jan 2006
    Posts
    260

    Switching Power Input

    Ok, so heres my problem for my screen i want to give it 12v regulated power, so i have this regulator, but my screen also draws its memory power from there. So i want to somehow rig something up that would give it power from one source when the acc line comes in and then it switches to another when that line drops out.
    heres a pic i quickly made to help explain



    Cheers
    98 V6 Camry XLE
    Status-Everything is working again!
    No progress while I am in NYC
    Ze Worklog

  2. #2
    Variable Bitrate
    Join Date
    Jan 2006
    Posts
    260
    hump de bump
    98 V6 Camry XLE
    Status-Everything is working again!
    No progress while I am in NYC
    Ze Worklog

  3. #3
    Variable Bitrate
    Join Date
    Jan 2006
    Posts
    260
    my only thought is some sort of relay that is triggered when the power goes off. and have that inline with the current hookup
    98 V6 Camry XLE
    Status-Everything is working again!
    No progress while I am in NYC
    Ze Worklog

  4. #4
    FLAC Jahntassa's Avatar
    Join Date
    May 2005
    Location
    Conyers, GA
    Posts
    1,417
    You could probably do the relay, but you might have problems because there'd be a moment where the circuit disconnected.

    The other idea is see if you can get a cheap 12v regulator to throw in-line with the screen and battery.

  5. #5
    MySQL Error MatrixPC's Avatar
    Join Date
    Sep 2003
    Location
    Beach City, Socal
    Posts
    4,053
    Here ya go. I did the same thing for all my screens.
    When car is NOT running, it take power from the battery, and get power from the regulator when car running.


    87a (N/C) Input => go to ACC or Battery + (if you want full time on)
    87 (N/A) Input => go to 12V (regulator output)
    30 (COMMON) output => go to LCD +
    86 (COIL -) go to car frame (battery -)
    86 (COIL +) to go alternator charging circuit. This is only available when the alternator is turning/charging => car running. You may be able to find this at the alternator fuse in the camry.
    2004 Matrix XR A7N8X-VM/400 AMD XP-M 2500+, DS-ATX
    89 Supra Turbo P3 600E@750/Abit BE6 II, Alpine M-BUS Car2PC.
    Y2K Accord Dell GX150
    RoadRunner is the best FE PERIOD
    EmoRebellion is a SCAMMER

  6. #6
    FLAC evandude's Avatar
    Join Date
    Mar 2005
    Location
    Maine
    Posts
    937
    it seems to me it would be better to have it controlled by the regulated output from the carPC... ie - (COIL +) to the regulator output, instead of the alternator charging circuit.

    That way it would power the screen from the regulated output whenever it was available, and whenever the regulated output was shut off it would switch to the car battery power, as opposed to being determined by whether the car is running or not.

    You may have to put a capacitor on the screen power input, because during the time when the relay is switching, it will have no power. The screen's internal power circuitry may have enough capacitance to continue working for those few dozen milliseconds, but if you have issues you might try it.
    But don't take it from me! here's a quote from a real, live newbie:
    Quote Originally Posted by Viscouse
    I am learning buttloads just by searching on this forum. I've learned 2 big things so far: 1-it's been done before, and 2-if it hasn't, there is a way to do it.
    eegeek.net

  7. #7
    Variable Bitrate
    Join Date
    Jan 2006
    Posts
    260
    i see what you guys are saying. ill go pick up a relay and do it.
    Couldnt I even do the coil+ with the acc line? That would be the same as the regulator. But perhaps doing the regulator is the best idea, that alllows it to even close on the regulated power.

    cheers guys
    98 V6 Camry XLE
    Status-Everything is working again!
    No progress while I am in NYC
    Ze Worklog

  8. #8
    MySQL Error MatrixPC's Avatar
    Join Date
    Sep 2003
    Location
    Beach City, Socal
    Posts
    4,053
    Quote Originally Posted by evandude
    it seems to me it would be better to have it controlled by the regulated output from the carPC... ie - (COIL +) to the regulator output, instead of the alternator charging circuit.
    The reason I pick the charging circuit is that the only time I know that the input power is 14V+.
    I don't want to use the PSU because it not always on in my setup.
    2004 Matrix XR A7N8X-VM/400 AMD XP-M 2500+, DS-ATX
    89 Supra Turbo P3 600E@750/Abit BE6 II, Alpine M-BUS Car2PC.
    Y2K Accord Dell GX150
    RoadRunner is the best FE PERIOD
    EmoRebellion is a SCAMMER

  9. #9
    Variable Bitrate
    Join Date
    Jan 2006
    Posts
    260
    excellent, problem fixed. you guys are great

    cheers!
    98 V6 Camry XLE
    Status-Everything is working again!
    No progress while I am in NYC
    Ze Worklog

Similar Threads

  1. FAQ: Power Supplies Explained (Part 1)
    By Bugbyte in forum The FAQ Emporium
    Replies: 14
    Last Post: 06-10-2007, 08:45 AM
  2. My low cost, easy to build power supply...
    By SkinnyBoy in forum Power Supplies
    Replies: 52
    Last Post: 09-27-2006, 07:10 PM
  3. Thinking of switching over to M-Atx - how much power?
    By OrangePeel in forum General Hardware Discussion
    Replies: 6
    Last Post: 05-20-2004, 08:59 AM
  4. getting an odd motherboard to power on
    By karmann in forum Power Supplies
    Replies: 13
    Last Post: 11-28-2001, 06:27 PM

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
  •