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A light detecting book light.

  1. Feb 2, 2009 #1
    Firstly, the book light works fine. I'm also attaching a circuit diagram.

    I don't really understand why the emitter of the transmitter (its marked with an E) takes in the current. Could someone explain to me how this circuit works?
  2. jcsd
  3. Feb 6, 2009 #2


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    There's a circuit diagram? :wink:
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