Announcement

Collapse
No announcement yet.

question regarding DC/DC supply

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • question regarding DC/DC supply

    Okay guys, I am working on the DC/DC supply for my carputer and had a few questions and wanted a few opinions regarding what i'm using.

    Just for a little background, my system does not need negative voltages for anything (my sbc generates them onboard i think).

    For 5V, I am using an Astec power module that accepts 9-36V DC and adapts it down to 5V at up to (a theoretical) 3A.

    see below link for a pic of the module. http://www.geocities.com/mp3lantra/power.html

    12V is where things may get a little tricky for me. I dont need all that much to run the hard drives or mainboard, but my 10" VGA LCD runs off 12V @ 2A and I would like to run it off of the same supply unit (if possible). My question is, are there any regulators (cheap *** linears only do 1A if i recall) beefy enough to give me the 2-3A I need?

    I also am thinking that I would need some sort of crowbar or tank circuit (I've seen some that use a 50mH inductor and a 2200uF capacitor) to protect from startup voltages and to smooth out the input. What are your thoughts on this?

    Thanks for any help that can be provided.

    -Lee

  • #2
    There are several 12V linear regulators rated from 1-5A. Search the National Semiconductor site and you should find them. You will need to use a "low dropout" variety. You shouldn't need any filtering, except for a few capacitors at the input and output of the regulator.
    Player: Pentium 166MMX, Amptron 598LMR MB w/onboard Sound, Video, LAN, 10.2 Gig Fujitsu Laptop HD, Arise 865 DC-DC Converter, Lexan Case, Custom Software w/Voice Interface, MS Access Based Playlists
    Car: 1986 Mazda RX-7 Turbo (highly modded), 1978 RX-7 Beater (Dead, parting out), 2001 Honda Insight
    "If one more body-kitted, cut-spring-lowered, farty-exhausted Civic revs on me at an intersection, I swear I'm going to get out of my car and cram their ridiculous double-decker aluminium wing firmly up their rump."

    Comment


    • #3
      If you need the current, have a look at the LM2576 voltage "regulators" they'll put out 3amps. I know someone who's used them before and had no problems, and 4 external component's makes them pretty simple.

      Hope that helps.

      Rob
      And you say people actually pay money for M$ Windows?
      www.mp3mini.co.uk (Does what it says on the URL) www.openclassic.co.uk (The new car, with zero rust!) www.rob-web.co.uk (My other site)
      Total re-design underway: on the whole progress is very slow as the car is taking up too much time :)

      Comment


      • #4
        Hey buddy .. i know the exact regulator you can use .. its called LM1084 from national it come in 5, 12, 3.3 its rated 5amps

        Very cool chip !:-) got 10 of them

        Mastero

        Comment


        • #5
          Originally posted by mastero:
          <STRONG>Hey buddy .. i know the exact regulator you can use .. its called LM1084 from national it come in 5, 12, 3.3 its rated 5amps

          Very cool chip !:-) got 10 of them

          Mastero</STRONG>
          They don't work, for some reason, not happy with a 14volt input, the 12volt ones that is, they won't regulate right..

          Comment

          Working...
          X