Switching Supplies For A Microcontroller

Discussion in 'The Projects Forum' started by ozwurld, May 13, 2014.

  1. ozwurld

    Thread Starter New Member

    Oct 13, 2013
    2
    0
    Hello all,

    I am currently busy with a project that involves powering a micro controller from a 7V solar panel. I would like for the Micro controller to be able to switch to a back up battery pack whenever the Solar Panel doesn't provide enough output voltage to power the micro controller i.e at night preferably.

    Can anyone please suggest how i can go about doing this.

    :)Thanks.
     
  2. Alberto

    Active Member

    Nov 7, 2008
    169
    36
    Simply use two diodes!

    Battery ----------->|------|MCU|--------- |<--------- Photovoltaic

    Cheers

    Alberto
     
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  3. tracecom

    AAC Fanatic!

    Apr 16, 2010
    3,869
    1,393
    Just be aware that some μCs can be damaged by a 7V power supply. Or maybe you have a regulator between the solar panel and the μC? If you use the diode solution, also note that there will be a voltage drop of up to .7V across the diode.
     
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  4. MrChips

    Moderator

    Oct 2, 2009
    12,414
    3,353
    You don't need 7V. Microcontrollers are now readily available that run on 3.3V.
    Use a low voltage photo-voltaic energy harvester such as LTC3105 to charge the battery. Then power the microcontroller from the battery via a 3.3V low drop-out voltage regulator.
     
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  5. ozwurld

    Thread Starter New Member

    Oct 13, 2013
    2
    0
    Does the picture i have attatched correctly assume your proposed solution "alberto"?


    [​IMG]
     
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