Announcement

Collapse
No announcement yet.

Alternative power

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

  • Alternative power

    Has anyone thought about just using some power transistors set up as emitter followers. I don't know if a drive will spin up at 11.5 volts, but it would eliminate all the switching circuit stuff and amperage wouldn't be a problem.

    home page

  • #2
    Voltage drop to 5V at supply currents that a motherboard requires would mean significant power dissipation. I am certainly considering an emitter follower for the 12V supply (I am currently using a 7812 regulator which has a fairly significant voltage drop, which an emitter follower would reduce to 0.6V (approx)).

    Rob


    ------------------
    -- <A HREF="http://www.nav.to/robwithey" TARGET=_blank>http://www.nav.to/robwithey
    </A>
    Old Systems retired due to new car
    New system at design/prototype stage on BeagleBoard.

    Comment


    • #3
      Why not just use a flyback regulator with input voltage of 8- 16v. that will fix your problem with +12v.

      ------------------

      Fosgate
      Fosgate

      System Comp V3 - In progress.
      Low power MB with C7 CPU, DC-DC PSU, car ECU link, USB TV, GPS, 7" TFT, Wireless, Voice.

      Comment


      • #4
        Simple answer to that, flyback converters are more complicated. I like simple things. Why use an overengineered solution when you don't need to - more expense, complexity, more to go wrong, more to screw up when building it.
        :-)

        Rob


        ------------------
        -- <A HREF="http://www.nav.to/robwithey" TARGET=_blank>http://www.nav.to/robwithey
        </A>
        Old Systems retired due to new car
        New system at design/prototype stage on BeagleBoard.

        Comment


        • #5
          Not really mate.

          Its all matter of getting two free samples (such as IC and Trans) and few more components (3 diods and caps)... and thats it.
          And you can be sure that that flyback rgulator is most relible and pretty much efficent with enough current to power up you mp3 player!


          ------------------

          Fosgate
          Fosgate

          System Comp V3 - In progress.
          Low power MB with C7 CPU, DC-DC PSU, car ECU link, USB TV, GPS, 7" TFT, Wireless, Voice.

          Comment


          • #6
            Power aint a problem with my mobo. a 2A 7812 works just perfect. Motherboard never resets when I start the car. Most switchers I've seen require an inductor. The inductor (8A, 300uH) I hooked up to my L296 cost more then the regulator chip itself. Then the smoothing caps needed to be special high frequency elctrolytics. And the high current diode wasn't cheap. My 7812 based regulator is just one TO220 regulator and a regular electrolytic cap, all very cheap low-tech and compact stuff. Works for me, so I'm sticking with it. :-)

            Rob


            ------------------
            -- <A HREF="http://www.nav.to/robwithey" TARGET=_blank>http://www.nav.to/robwithey
            </A>
            Old Systems retired due to new car
            New system at design/prototype stage on BeagleBoard.

            Comment

            Working...
            X