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When is a flyback diode necessary?

Discussion in 'Electronic Projects Design/Ideas/Reviews' started by Trisorion, Nov 3, 2008.

  1. duffy

    duffy New Member

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    Sounds cool.

    Wait, what - ?
     
  2. Hero999

    Hero999 Banned

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    That's not true, with the diode in place the maximum voltage will be the forward voltage of the diode.

    The diode only has to be rated to the same voltage as the maximum power supply voltage.

    Although it doesn't matter here, you can speed the turn off time by including a resistor of the same value as the coil's resistance in series with the diode. This helps to prolong the life of relays as the contacts will open faster and arc less.
     
    Last edited: May 30, 2009

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