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Broken arduino uno

Discussion in 'Arduino' started by rascupanamuha, Jun 16, 2013.

  1. be80be

    be80be Well-Known Member

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    There's a lot of If's the higher the voltage the hotter the regulator get's when you use a lot of current.
     
  2. ADWSystems

    ADWSystems Member

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    I'm only concerned about the Arduino (an UNO) and the only other constant load on the regulator would be the LCD display. All the constant loads external to the Arduino are 12V powered, and the remainder are not constant (switch inputs) and are minimalized.

    Do we know how much current the Arduino regulator can provide vs heat? How much of the current is used by the Arduino board itself?
     
  3. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    I would imagine it's fairly low current, as is the LCD display (depending on the back-light LED current) - I see no problems feeding it off 12V, or indeed 24V (as long as the regulator is happy at 24V?).

    The current is easily measured, give it try.
     
  4. dave

    Dave New Member

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  5. b.james

    b.james Member

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    You will have no trouble because although the voltage is high the current usage is very small . If your regulator gets hot on the arduino fit a chunk of aluminium or other heat sink
     
  6. ADWSystems

    ADWSystems Member

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    And just how would you propose to add a heatsink to the regulator on the Arduino UNO board?
     
  7. b.james

    b.james Member

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    Glue it to the top silly
    Chop up a small bit of aluminium to fit
    Even remove the smd and solder a larger or bridge the two
    Pardon me for replying Jeesh!
     
  8. ADWSystems

    ADWSystems Member

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    I couldn't figure out how to mount a heatsink to a SMD regulator. Though attaching the heatsink to the non-conductive package would not be ideal, it would probably add enough margin to run from 12V reliably (ie., forever).
     
  9. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    It's a standard technique, they even make stick-on heatsinks for that very purpose (SM packages).
     
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  10. Rich D.

    Rich D. Member

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    I fried an Arduino (Leonardo) in that same area, the area around the connector gets/got very hot. In my case I was asking for a bit too much from the 5V supply output to power an LCD with backlight. Even with only 8Volts input she burned right up. I find it interesting (annoying actually) that there is no specification from Arduino on the max current you can use for the 5V output, only the 3.3. Apparently it's not a lot. Also I would think that there was a overcurrent/temp limiter in there somewhere, but my $30 lesson is I guess not.

    So if all else fails, consider that the input voltage may not be the problem, but the demand from the power circuit could be frying your electronics. So if you are using any 5V, do yourself a favor and get a nice, tough 7805 in a TO-220 package and don't rely on the Arduino to supply any juice.
     

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