Help in making a 5v regulator

Discussion in 'General Electronics Chat' started by Sharfuddin Shawon, Nov 5, 2013.

  1. Sharfuddin Shawon

    Thread Starter New Member

    Nov 5, 2013
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    0
    What to do, if i want to get 5v/2a from a 6v/4.5Ah battery?
    I am totally newby to elecs. Any kind of suggestion is welcome.

    Thanks...
     
  2. ajm113

    Member

    Feb 19, 2011
    176
    5
    What are you powering that need two amps if I may ask? Most projects are fine with 1A. I've seen mass communication appliances that only require 1A from their transformer.
     
    Last edited: Nov 6, 2013
    Sharfuddin Shawon likes this.
  3. Sharfuddin Shawon

    Thread Starter New Member

    Nov 5, 2013
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    Aaah, i am tryna power my Raspberry Pi with it.
    2amps will be fine for using all ports of it...
     
  4. Sharfuddin Shawon

    Thread Starter New Member

    Nov 5, 2013
    6
    0
    Hey r u there?
    Wud u help me in making a power supply from a 6V/4.5AH battery. What puts out 5v and 2amps?
     
  5. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    5,783
    1,103
    The RPi is specified as needing a 700mA supply. If that's the maximum the RPi can handle then is trying to draw more current via its ports a wise move?
     
  6. ajm113

    Member

    Feb 19, 2011
    176
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    I agree. What exactly are you trying to control with the guy? If I'm using a micro controller to control say relays or a motor. I wouldn't exactly try to push 2AMPs into the tiny thing, unless your trying to kill it.

    I would use n-channel mosfets to control high power devices from a microcontroller/Raspberry. Just have an I/O pin from the Pie connected to the Gate pin on a n-Channel MOSFET and on the source pin connect it to the battery. Of course to supply power to the Raspberry just look for small efficient 5v regulators that pump half an amp. Jameco.com is a good place to look for these.

    Or you can build one using a zener diode. Just google voltage regulator zenor diode. Obviously wouldn't be as safe as a prebuilt voltage regulator. Because you loose some of that reverse voltage protection.

    NOTE: If your dealing with anything with a relay/motor/etc with a coil. Add a reverse diode to stop reverse voltage. Something like the 4001 diodes are pretty good.
     
    Last edited: Nov 7, 2013
  7. bountyhunter

    Well-Known Member

    Sep 7, 2009
    2,498
    507
    You need a 2A LDO regulator. BTW, your "6V" battery probably isn't anywhere near 6V as it gets near end of discharge, it's a lot lower. You need to factor that into the LDO design.

    One way to build a simple 5V LDO would be using the LP2975 controller IC and an external FET.
     
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