Configuring DC mix connection circuit

Discussion in 'General Electronics Chat' started by Mohammad abdullah, Sep 10, 2016.

  1. Mohammad abdullah

    Thread Starter New Member

    Mar 30, 2015
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    Hi,
    I want to connect Peltier 12706 to solar panel that produce 11A ,3 Peltier in Series and then 3 rows parallel of the series total 9 Peltier in each string I want 2.5A to be passed only so the hot side doesn't get too much hot I should use DC-DC booster to get 18V for every string of 3 but for current, What should I do so it will not pass more than 2.5A?
    P.png
     
  2. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    No Matter what the hot side will get HOT.
    A Heat sink in necessary to prevent peltier melt down
     
  3. AlbertHall

    Well-Known Member

    Jun 4, 2014
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    Each element is ≈2Ω making a string of three ≈6Ω. Applying 18V would give each string about 3A.
    The total power for three strings would be 160W. If the solar panel will produce 11A at 14.5V it will be fully loaded, but there will be losses along the way so it might struggle a bit to manage that.
     
  4. Mohammad abdullah

    Thread Starter New Member

    Mar 30, 2015
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    But I don't have to have any thing between the booster and the Peltier so one string don't take all the power letting the others power less.

    My solar panel rated 180W and I can arrange 200W but I know that it will not produce all that especially our ambient +40 C sometimes 52C because of that I don't want it to got fully loaded so it well not melt down.
     
  5. AlbertHall

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    The three strings will share the available power equally.
    The solar panel will not be harmed at all by overload - they can be quite safely short-circuited. As you draw more current the voltage will fall so there is an optimum load to get maximum power from a solar panel.
     
  6. Mohammad abdullah

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    Mar 30, 2015
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    So the governor of the current will be the panel produce current, but if I want to control the current flow I should put diode.
     
  7. AlbertHall

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    A diode won't control the current. If your DC-DC converter has an adjustable output voltage you can use that to control the current.
     
  8. Mohammad abdullah

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    Mar 30, 2015
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    How is that will be? I know that if you increased the voltage the current flow increases but for the Peltier isn't it has maximum voltage rate.

    I tried one and it explode :)
     
  9. AlbertHall

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    Yes, they have a maximum voltage but the arrangement you have described is well below the maximum for the peltier you have chosen - check the datasheet..
     
  10. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    No matter how you control the voltage.

    Your peltier will explode if you do not mount it on a HEATSINK

    You can adjust the Peltier voltage to minimize current but you will lose efficiency.
    You can ON OFF the peltier power to control the cold temperature
     
  11. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    Why don't you understand that the hot side will get hot. Even with low current, it will heat to the point where it will split into 2 or explode.
    YOU NEED A HEATSINK
     
  12. Mohammad abdullah

    Thread Starter New Member

    Mar 30, 2015
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    What it will be the add of three or one only?
     
  13. AlbertHall

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    Read the datasheet.
     
  14. Mohammad abdullah

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    Mar 30, 2015
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    it will be controlled by thermostat at hot side 50 degree bellow joints melting point
    also I want to use it as water warmer :)
     
  15. Mohammad abdullah

    Thread Starter New Member

    Mar 30, 2015
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    It says 14.2V @25C and 16.4@50C.
    but I had 3 in series should I multiply it by 3 or it will be as one Peltier that what I meant.
     
  16. AlbertHall

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    Three in series will be three times the maximum voltage.
     
  17. Mohammad abdullah

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    Mar 30, 2015
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    So if I adjusted the voltage it will control the current?

    even if I connected it to battery bank it will act the same?
     
  18. AlbertHall

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    Yes.
     
  19. R!f@@

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    Are u mounting the peltier on any thing ?
     
    Mohammad abdullah likes this.
  20. Mohammad abdullah

    Thread Starter New Member

    Mar 30, 2015
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    Thank you very much for your kindness and time :)
     
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