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Charging a capacitor from a 4v solar panel

  1. Mar 12, 2016 #1
    Will a 4V solar panel connected to a 100V rated capacitor stop charging the cap at 4V or will the cap keep pulling ad infinitum? Seems like the capacitor has no knowledge of the notion "I am full so stop drawing current" else they would not get destroyed if the solar panel was 500V instead. I know how to protect the panel with a diode when the panel drops output below the caps charge.
     
    Last edited by a moderator: Mar 12, 2016
  2. jcsd
  3. Mar 12, 2016 #2

    rbelli1

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    Take the datasheet block diagram and make one of your own. Use higher voltage components. I would suggest using a canned switcher for that part of the circuit. Something buck/boost would be best. Search for SEPIC. There will be a "black box" somewhere in the diagram for the main MPPT controller. That special sauce is described in usually fairly good detail in the datasheet. Drop in a micro program it and you're good to go.

    BoB
     
  4. Mar 12, 2016 #3

    meBigGuy

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    The capacitor will charge up to the voltage on the source. Doesn't matter what its rating is. Read a little about RC circuits on wikipedia to make it clear.
     
  5. Mar 12, 2016 #4

    phinds

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    A cap does not care what voltage it's rated at as long as you don't exceed that rating. 4V hardly comes close to exceeding the rating of a 100V cap. How could you expect a 4V source to produce more than a 4V charge on a cap?
     
  6. Mar 12, 2016 #5

    Averagesupernova

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    That's what I was wondering.
     
  7. Mar 12, 2016 #6

    phinds

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    Well, can a 4V source produce more than 4V?
     
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