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12v to 5v 5A Power Supply

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  • 12v to 5v 5A Power Supply

    Hello guys,

    I looked a lot of projects, but this is the best, because with this, we can
    provide clean 5v power with 5A.

    I just made the Circuit Board, and mounted in my Honda Jazz to
    supply 3 USB hubs.

    The heart of this project is the LM338k Regulator, with a BIG Heatsink,
    this will get hot quickly... :-)

    After you place all in board, u just need to adjust the resistor, to get
    the 5v in output.

    C1 1 14000uF or 10000uf 40 VDC Electrolytic Capacitor
    C2 1 100uF 50Vdc Electrolytic Capacitor
    C3 1 0.1uF Disc Capacitor
    C4 1 0.01uF Disc Capacitor
    R1 1 5K Pot
    R2 1 240 Ohm 1/4 W Resistor
    U1 1 LM338K 1.2 to 30 Volt 5 Amp Regulator

    This is the link for the original project...
    ( I removed everything before the C1, because we have 12v DC)

    http://www.aaroncake.net/Circuits/supply.asp
    Attached Files

  • #2
    The LM338 is a linear regulator. About 60% of the power in a 12 to 5 volt linear regulator gets burnt up as heat. To deliver 50W to the load 65W is burnt as heat.

    Also, this design doesn't have a disable. It never turns off. Unless you have a relay controlling power to the circuit, your battery is toast! Running off your car's battery without the eingine running would drain it really quickly.

    I linear regulator is very stable and free of power line noise, but it is just not worth the waste.

    If you need BIG power to run your USB system, and want to do it with style and grace just follow the link in my sig. [email protected], 93% efficient, USB Sync'd, 300 kHz switch freq, and professionaly built.

    |
    |
    \/
    Order your ACPPSv1 Now! [email protected] DC-DC, computer sync'd accessory power supply.

    My Install
    My other hobby is more dangerous...

    Comment


    • #3
      A PT6625 is good for 5V at 5A : http://www.datasheetcatalog.org/data...nts/pt6625.pdf
      Old Systems retired due to new car
      New system at design/prototype stage on BeagleBoard.

      Comment


      • #4
        Originally posted by Rob Withey View Post

        Ooh, I like that chip... And 85%+ efficient for high current 5v out. Never even knew it existed. Good find!
        Fusion Brain Version 6 Released!
        1.9in x 2.9in -- 47mm x 73mm
        30 Digital Outputs -- Directly drive a relay
        15 Analogue Inputs -- Read sensors like temperature, light, distance, acceleration, and more
        Buy now in the MP3Car.com Store

        Comment


        • #5
          Originally posted by Rob Withey View Post
          $36.60 on digikey.com (Link)

          Still needs a little work to become an installable piece, but this will let people with minimal electronics knowlege create a 5V switcher PS for their carpc's in an afternoon.
          Order your ACPPSv1 Now! [email protected] DC-DC, computer sync'd accessory power supply.

          My Install
          My other hobby is more dangerous...

          Comment


          • #6
            lm7805

            Another voltage regulator you could use is the lm7805. Its cheap and if voltage between 5-20V is applied the output voltage is a constant 5V.
            VW GOLF MK1
            2.0L 8V
            T3/T4 TURBO
            NOS

            Comment


            • #7
              Originally posted by Kishon View Post
              Another voltage regulator you could use is the lm7805. Its cheap and if voltage between 5-20V is applied the output voltage is a constant 5V.
              Maximum power draw is less than the maximum draw on a standard USB hub, and definately less than 5A.

              Also it is not very stable over vast ranges of temperature.

              I love and use them all the time, they even appear on the FB.
              Fusion Brain Version 6 Released!
              1.9in x 2.9in -- 47mm x 73mm
              30 Digital Outputs -- Directly drive a relay
              15 Analogue Inputs -- Read sensors like temperature, light, distance, acceleration, and more
              Buy now in the MP3Car.com Store

              Comment


              • #8
                7805c

                Point taken regarding the temp. I don't know which type you are using. I have installed one of these..(below). they seem to handle up to 1.5A and you can add a heatsink.
                VW GOLF MK1
                2.0L 8V
                T3/T4 TURBO
                NOS

                Comment


                • #9
                  7805c

                  forgot the attachment.LOL
                  Attached Files
                  VW GOLF MK1
                  2.0L 8V
                  T3/T4 TURBO
                  NOS

                  Comment

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