transistor source

Discussion in 'The Projects Forum' started by sasek, Apr 12, 2010.

  1. sasek

    Thread Starter Member

    Jan 3, 2010
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    hai alll

    Here I want asking few question, could phototransistor work with AC source at collector and emitter terminal??? If possible what max voltage I could put over there, because i tried to find max voltage that phototransistor could support from a datasheet but not included.

    Thanks........:D
     
  2. retched

    AAC Fanatic!

    Dec 5, 2009
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    As long as the gate was supplied with a constant DC, It may work..
     
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  3. sasek

    Thread Starter Member

    Jan 3, 2010
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    is it collector have voltage limit???
     
  4. SgtWookie

    Expert

    Jul 17, 2007
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    Ahh, wait a minute....

    Are you trying to say you want to use a phototransistor with mains AC power?

    What exactly are you trying to do?
     
  5. retched

    AAC Fanatic!

    Dec 5, 2009
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    Ive got to start thinking early in the morning before I start responding..

    I was thinking in terms of low voltage a.c. I couldnt imagine them wanting to put 120vAC or 240vAC through a phototransistor. But I should have asked first.

    Are you wanting to try to use a phototransistor as a photo driven relay?
     
  6. sasek

    Thread Starter Member

    Jan 3, 2010
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    yup. i want use as driven relay with nice response
     
  7. SgtWookie

    Expert

    Jul 17, 2007
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    No, you can't use a phototransistor with mains power.

    You need to use low voltage DC with a phototransistor.
     
  8. sasek

    Thread Starter Member

    Jan 3, 2010
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    hummm...

    thanks info me.......
    do you know the suitable distance to separate LDR and LED to make them have good or maybe very good response....

    thanks reading :)
     
  9. retched

    AAC Fanatic!

    Dec 5, 2009
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    I think you may be trying to recreate the workings of a Solid-state relay. Have a look at SSR.
     
  10. sasek

    Thread Starter Member

    Jan 3, 2010
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    hummm actualy not.....

    im trying to control thyristor gate using digital method....... so i need analog optocoupler to control the firing angle. actually, thyristor gate depend on what???? current or voltage?????
     
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