7805 regulator + diode

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  1. - 13th June 2006, 08:32 #1
    DanPBP's Avatar
    DanPBP
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    Question 7805 regulator + diode

    Hello,

    I was wondering, do I need a diode protecting my circuit against a reverse polarity applied before the 7805 regulator?

    Or, can the 7805 regulator handle a reverse polarity error protecting the circuit attached to it?

    Thank you very much.

    Regards,
    Daniel.
  2. - 13th June 2006, 10:10 #2
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    No, a 7805 is not a reverce polarity protector. A series diode at the input site of an 7805 is a good protection of reverce polarity. Don't forget the extra capacitors at the input and the output of the 7805.
  3. - 14th June 2006, 08:34 #3
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    sayzer
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    Why don't you try?

    You can see the result with your own eyes; good or bad.
    "If the Earth were a single state, Istanbul would be its capital." Napoleon Bonaparte
  4. - 14th June 2006, 10:41 #4
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    Yes, I know I could have tried, but I didn't want to burn a good regulator by changing the polarity.

    Thanks!
  5. - 14th June 2006, 20:45 #5
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    Quote Originally Posted by sayzer
    Why don't you try?

    You can see the result with your own eyes; good or bad.
    Use eye protection (safety glasses)!! ;-)
    Jim Robertson
    "MilesTag" DIY Lasertag
    www.lasertagparts.com/mtdesign.htm
    Dayton, Ohio
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