Photo diode or photo transistor?

Discussion in 'General Electronics Chat' started by Hansen, Jun 7, 2015.

  1. Hansen

    Thread Starter New Member

    May 3, 2015
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    Is there another source?
     
    Last edited: Jun 7, 2015
  2. DickCappels

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    Hansen likes this.
  3. bertus

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  4. Hansen

    Thread Starter New Member

    May 3, 2015
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    If I use a photo transistor and remove the light, will it open the circuit, or is it latched?
     
  5. DickCappels

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    Aug 21, 2008
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    It will open. Very little current through the collector and emitter when it is in the dark.

    Check out those links in earlier posts.
     
  6. Hansen

    Thread Starter New Member

    May 3, 2015
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    If I don't want any current going through when it's dark, would a photo diode work? Note: I prefer not to add any resistors to the circuit.
     
  7. crutschow

    Expert

    Mar 14, 2008
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    Both carry no current in the dark, but the photo diode is much less sensitive to light (less current flows when illuminated).
    What are you doing with the circuit if it has no resistors?
     
  8. Hansen

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    May 3, 2015
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  9. crutschow

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    Y
    It would appear that is correct.
    For that I would recommend a photo-transistor device.
     
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  10. KeepItSimpleStupid

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    Mar 4, 2014
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    Until post #8, I thought I missed something.
     
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