Unsure as to diode polarity in battery charger circuit

Discussion in 'The Projects Forum' started by Max12345, Oct 14, 2016.

  1. Max12345

    Thread Starter Member

    Aug 27, 2013
    63
    0
    Greetings
    I have recently acquired an Einhell 7.2V (Ni-Cd) cordless drill with a battery charger.
    The (only) diode had been removed and was loose.
    I have attached a reverse-engineered schematic as well as a pic of the little board.
    There is a white arrow where the diode goes, but I am still unsure as to the direction/polarity, as I am not sure
    whether it is forward- or reverse-biased.
    Does anybody have any ideas please?

    Also, it seems that the green led which should indicate a full-charged status will aways be on?

    Thank you
    Max
     
  2. MrChips

    Moderator

    Oct 2, 2009
    12,446
    3,362
    1N4001 diode must be forward biased as in B. This branch of the circuit provides the charging current.
    GREEN LED stays ON all the time.
    RED LED stays ON while charging. Goes OFF when battery is charged.
     
  3. Max12345

    Thread Starter Member

    Aug 27, 2013
    63
    0
     
  4. Max12345

    Thread Starter Member

    Aug 27, 2013
    63
    0
    MrChips, my gratitude knows no bounds, thank you.
    Max
     
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