Page 2 of 2 FirstFirst 12
Results 11 to 16 of 16

Thread: Diy Dc Ups

  1. #11
    Fox Furry crenn's Avatar
    Join Date
    Apr 2005
    Location
    In the shadows behind you
    Posts
    4,067

    Default Re: Diy Dc Ups

    Quote Originally Posted by xmastree View Post
    You'll probably find the modem and router will work happily on a wider voltage range, maybe 10 - 14V so I wouldn't worry too much about regulation.
    The battery will be at 13.8 fully charged, you could feed that into a 12V reg if you like (as in the above circuit) but once the battery is running, that will drop and you won't have enough overhead to get 12V at the output even if the battery is healthy.
    That's why I'm looking at a switch mode power supply. A little 60W one for a Mini ITX board is all I should need providing it has the features I want.
    Antec Sonata II | Pioneer DVR-212
    Good news! You can follow my website or follow me on twitter!

  2. #12
    High-tech Redneck crazybillybob's Avatar
    Join Date
    Jun 2005
    Location
    Currently Homeless
    Posts
    1,028

    Default Re: Diy Dc Ups

    Crenn,
    For what your doing you don't need the "inverter" as listed in your linkage.
    You really could do it all from a 12Vdc perspective. In your case the inverter is just a waste of energy, by skipping it you'll make a smaller, lighter, cheaper, more efficient design. Your looking for a DC to DC 2 source converter with auto switching.
    I've got a circuit that does most of what you want except check that the batt isn't dead (under volt). It doesn't use any micros. I'm sure that you can find a chip that will do everything you need, I think maxim has a couple of IC's that will do it.

    Good luck!
    CrazyBillyBob

  3. #13
    High-tech Redneck crazybillybob's Avatar
    Join Date
    Jun 2005
    Location
    Currently Homeless
    Posts
    1,028

    Default Re: Diy Dc Ups

    I think with a little work you could use a microproc to measure the battery voltage, if it's low; trip a load relay off to disconnect the load from the battery.

  4. #14
    SOB Fettler xmastree's Avatar
    Join Date
    Mar 2006
    Location
    Burnley, Lancs. UK
    Posts
    1,704

    Default Re: Diy Dc Ups

    Quote Originally Posted by crazybillybob View Post
    I think with a little work you could use a microproc to measure the battery voltage
    What's wrong with a comparator?

    Quote Originally Posted by aintnothang View Post
    Think of a way to simulate a real bullet hole, like shooting it.

  5. #15
    High-tech Redneck crazybillybob's Avatar
    Join Date
    Jun 2005
    Location
    Currently Homeless
    Posts
    1,028

    Default Re: Diy Dc Ups

    as long as you build a little hysteresis into the limits it should work just fine. I just don't have a comparator circuit within easy reach.

  6. #16
    Fox Furry crenn's Avatar
    Join Date
    Apr 2005
    Location
    In the shadows behind you
    Posts
    4,067

    Default Re: Diy Dc Ups

    A comparator is more simple to implement than a HC12. I don't have any spare HC12 chips either.
    Antec Sonata II | Pioneer DVR-212
    Good news! You can follow my website or follow me on twitter!

Posting Permissions

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